Labor processes and methods of their research. Methods for studying labor processes and working time costs

Labor standardization method - this is a way of studying the labor process according to its main elements and determining the method by which the labor standard is established. In general, there are two fundamentally different methods of labor standardization - summary and analytical (element-by-element).

Summary method of labor standardization is that labor standards are established taking into account the average level of their implementation based on own experience standardizer. It provides for the development of labor standards experimentally not for individual elements of the labor process, but for the entire process at once, that is, in total, by determining the average actual output of one or a group of workers (find the average statistical value).

Application this method is extremely limited due to the fact that it does not sufficiently take into account the advanced experience of production technology and labor organization, its rational methods and techniques, and does not reveal possible reserves for increasing labor productivity through advanced training of workers, the introduction of more advanced technical means and other factors. Therefore, the method of summary labor standardization can be applied only to a limited range of work that is rarely performed, as well as to urgent work that needs to be completed, but there are no labor standards for them.

Taking into account the above in the practice of labor standardization in agriculture mainly used analytical (element-by-element) method of labor standardization , which is also called technical labor standardization, since it involves dividing the labor process into separate components, followed by a detailed study of the time spent on each of them, methods and techniques of labor, and determining the rational sequence of the labor process.

The study of working time costs in a particular labor process is preceded by an analysis of its organization, which involves dividing it into its component elements. To do this, lay out production process , which is a collection labor processes, combined and based on accepted production technology with the aim of producing material goods necessary to meet people's needs. The decomposition of the production process into its component parts is the starting point of the main method of labor standardization - analytical, or element-by-element.

Each production process can be considered in two aspects: as a set of changes that affect the subject of labor and as a set of actions of workers aimed at expedient changes in the subject of labor. In the first case we are talking about the technological process, in the second - about the labor process. In some cases, all operations of such a group create a continuous technological chain along which the subject of labor moves until a certain technological goal is achieved. The presence of such groups of operations makes it possible to introduce the current organization of labor in agricultural production. Therefore, the division of the harvesting process into production stages or partial production processes, operations and their groups is not only technological, but also of a certain organizational nature.

Production stage (partial production process) - this is a homogeneous and technologically complete part of the production process, which is characterized by a sequence of changes in the state of objects of labor and organizational isolation. A separate production process, in turn, is divided into separate labor processes and labor operations.

Separate labor process - This is a purposeful set of influence of one or a group of workers on objects of labor with the help of means of labor in order to change their content and transform them into a different quality.

Under labor operation understand a technologically and organizationally isolated element of the labor process, which is periodically and sequentially repeated in time and space and is carried out by one or a group of performers at the same workplace using the same tools.

Operations and work processes are divided into simple and complex depending on whether they involve one or more actions on the subject of labor. Simple ones include plowing, harrowing, rolling and others, and complex ones include sowing, transporting seeds and fertilizers, harvesting, etc.

Labor reception - This is a complete set of actions and movements of the performer in time, which are performed sequentially one after another and have a specific purpose.

Labor action is a set of several movements performed without interruption by one or several working organs of a person (arms, legs, body) with unchanged objects and means of labor and have a specific purpose.

Labor movement - This is a one-time movement of a person’s working organs when performing a labor action.

A diagram of the relationships between these elements of the production process is shown in Figure 11.1.

The analytical (element-by-element) method of labor standardization has two complementary methods: analytical-experimental and analytical-calculated.

Analytical and experimental method of labor standardization provides for the decomposition of the production process into its component elements - operations, techniques and their complexes, actions and movements through certain observations. Based on the results obtained, reasonable standards for the time spent on performing individual elements of the labor process are established and the labor standard is calculated from them. Directly on farms, this method is used in cases where there is a need to check and clarify standard standards, in the absence of standards in reference books or when they are defined for work using new types of equipment. Its value lies in the fact that it makes it possible to identify shortcomings in the existing labor organization and outline measures to eliminate them. Disadvantages - it is quite complex and labor-intensive, since in order to establish a technically sound labor standard it is necessary to perform a certain number of high-quality observations.

Rice. 11.1.

Taking this into account, it is often used analytical and calculation method of labor standardization, when labor standards are calculated according to pre-established time standards for performing individual elements of labor operations. Such standards are given in special reference books with differentiation in accordance with specific natural, organizational, technical and other production conditions. When rationing labor in this way, passports of fields and livestock buildings are used, therefore in agriculture this method is the main one. It should be noted that these standards are developed using the analytical and experimental method of standardized institutions.

To calculate labor standards using an analytical and calculation method, those that meet certain production conditions are selected from reference books of labor standards, which are substituted into the appropriate formulas and the labor standard is determined. Calculations must be accompanied by certification of fields and farms. The analytical and calculation method of labor standardization is less labor-intensive compared to the previous method, and provided that farms are provided with reference books of standards and their correct use, it is possible to determine reasonable labor standards.

Introduction

2.4 Timing

Conclusion

Introduction

In market conditions and competition, it is of great importance for every enterprise to reduce production costs and thereby obtain greater profits. An important area of reducing production costs is improving labor processes and reducing lost working time. Based on the information obtained as a result of research into labor processes, most problems related to the design of labor organization and its standardization are solved.

The relevance of this topic is due to the search for new approaches to labor management of enterprise personnel in modern conditions; the need to increase professional level to change traditional management systems of social and labor relations, personnel and production, using more effective forms and methods of management. Labor problems affect the interests of all categories and groups of the population in matters of organization and regulation of labor, its payment and other issues considered by economics and the sociology of labor.

The study of the labor process involves an analysis of all its characteristics that affect labor costs and the efficiency of use of production resources. The design and technological parameters of the equipment, its compliance with the manufactured products and ergonomic requirements are studied; professional qualifications, psychophysiological and social characteristics of workers; working conditions, technology used, organization of the workplace, its maintenance, etc.

Based on the objectives of the study, methods for obtaining and processing information are selected. The optimality criterion is the minimum total costs associated with obtaining the necessary information and its subsequent use.

When organizing work highest value have two tasks related to the study of labor processes:

1) determination of the actual time spent on performing elements of operations (labor movements, actions, techniques, etc.);

2) establishing the structure of time spent throughout work shift or parts thereof.

Determining the duration of the elements of operations is necessary for developing time standards, choosing the most rational labor methods, establishing the components of time standards, and analyzing the quality of standards and standards.

Data on the structure of working time costs are used in developing standards for workplace service time and preparatory and final time, assessing the efficiency of using working time, and analyzing the existing organization of labor and production. Thus, this topic remains quite relevant today.

The purpose of the work is to study the problem of studying labor processes and working time costs. To do this, it is necessary to identify the types and classification of labor processes, methods of studying labor processes, such as timing, photography of working hours, etc.

The work consists of an introduction, two parts, a conclusion and a list of references.

1. General characteristics of methods for studying labor processes

It is possible to rationally design the labor process and ensure the validity of labor standards only on the basis of initial information and special research. The main goals of such studies are:

analysis of the operation structure and working time costs;

obtaining information about factors affecting working time costs;

determination of the magnitude and causes of losses and waste of working time;

obtaining data for the development of norms and standards;

assessment of the quality of applied norms and standards, reasons for non-compliance (over-fulfillment) of norms;

comparative assessment of the rationality of the techniques and methods of work used;

obtaining initial data for the development of instructional and technological maps.

The main object of rationing is the production operation.

An operation is understood as a part of the production process performed on a specific object of labor by one or a group of workers at one workplace. The production operation is divided into its component parts:

A) Labor movement. It is the initial element of the labor process and represents one-time actions of the worker.

b) Working technique. It is a complete set of worker actions, characterized by a purpose.

V) Set of techniques. A group of techniques combined according to technological characteristics.

G) Passage - repeated actions carried out on the same object of labor at one workplace.

d) Transition- part of the surface treatment operation with the same tool used and equipment setup. There are several transitions in an operation - roughing, finishing, trimming, etc.

For scientific and organizational work and the establishment of technically sound standards in production, it is necessary to study the content of the work and the time spent on its implementation by workers and equipment. This allows:

identify and eliminate lost working time due to more full use reserves of equipment, technology, labor and production organization;

achieve an optimal relationship between man and machine in the workplace;

generalize and specify the main directions for improving the organization of labor and production, as well as mobilize workers’ initiatives to increase production efficiency.

The objects of research on working time costs can be:

all types of costs and losses of working time, highlighting elements of operations and operational time;

preparatory and final time;

working hours for servicing workplaces;

certain types of lost working time;

time to complete individual elements of operations.

Methods for studying the labor process are divided into two groups: single-factor, in which one indicator is studied and recorded (for example, time), and multifactorial ( complex), in which not one, but a whole series of production indicators, directly related to the studied process.

For example, when studying the work process of a team, the quality of products, the employment of each member of the team, and the degree of use of equipment are recorded. Such a comprehensive study of working time costs is one of the main means of identifying and using reserves for increasing labor productivity through further tightening of the working day, best use technology, improvement of technology, organization of labor and production.

In the course of studying the labor process and its standardization, two problems are solved: determining the actual time spent on performing the operation and its elements; determining the structure of time spent during a shift (or part of it). Methods for studying working time costs implemented through direct measurements and momentary observations. Direct measurement method consists of continuous monitoring of the labor process, operation or its parts and recording current time readings or the duration of individual elements of the operation.

The study of labor processes is carried out taking into account the fact that the time spent on performing an element of an operation or a certain type of work depends on many organizational, technical and psychophysiological factors that usually cannot be completely controlled. In particular, measuring the duration of the same element of an operation under the same conditions gives a number of values that in most cases do not coincide with each other, i.e. the results of this measurement will form a variation series. Therefore, in order to obtain reliable conclusions about the duration of elements of operations and the structure of working time costs, methods of organizing and processing observations should be used that allow taking into account the probabilistic nature of the processes under study.

To obtain the necessary information from minimal costs It is very important to justify the number of observations. Methods for studying labor processes can be classified according to: the purpose of the study, the number of objects observed, the method of conducting observation, the form of recording its data, etc. Depending on the purposes and technique of observation, the following are distinguished: basic methods: photograph of working hours, method of momentary observations, timing.

Timing serves to analyze labor techniques and determine the duration of repetitive elements of operations. Working Time Photography (FWP) used to establish the structure of its costs during a work shift or part of it. The term “photography” quite accurately reflects the essence of this method. If, in timekeeping, the object of study is, as a rule, elements of operational time on specific type products, then the FWF records the time spent on all types of work and breaks that were observed during a certain period of time. In this case, the elements of operational time are allocated enlarged (before techniques or complexes of techniques).

The structure of time spent during FRF can be established according to various classification schemes. Photochronometry used to simultaneously determine the structure of time costs and duration of individual elements of a production operation.

Based on the number of objects observed, individual, group, and route observations are distinguished:

individual is the observation of one object (worker, machine);

group- for several objects. Types of group observation: brigade (over the workers of the team) and multi-machine (over workers and machines at a multi-machine workplace) observation;

route is considered to be the observation of an object that moves along a specific route, or of several objects located relatively far from each other and for which the observer moves along the corresponding route.

Depending on the objectives of the study and the characteristics of labor processes, there are various methods conducting timekeeping, photographs of working hours, phototiming.

Timing may be continuous(current time), selective and cyclic. When conducting timing observations based on the current time, all elements of the work are examined in the order in which they are performed. Selective timing is used to study individual elements of operations, regardless of their sequence. In cases where it is difficult to accurately measure the time spent on elements of an operation that have a short duration (3-5 s), cyclic timing is used. It lies in the fact that successive techniques are combined into groups with different composition elements being studied. Based on measurements of the duration of execution of groups of elements, the duration of each element of the operation included in them is determined. So, if there are techniques a, b, c, then they can be combined into three groups:

a + b = A, a + c = B, b + c = B.

Next, through observations, the execution time of each such group of techniques (A, B, C) is determined. As a result, we get three equations with unknowns a, b and c. After solving them, the execution time of individual elements is found.

Photographs of working hours differ in two main ways: the objects observed and the methods of conducting and processing observations. Based on the first criterion, photographs of the use of workers’ time are identified ( individual, group, self-photography), equipment, as well as a photograph of the production process. At individual photograph, the observer studies how time is used by one worker during a work shift or other period of time. Group photography is carried out in cases where work is performed by several workers, in particular with a team organization of work. One of the important tasks of this type of FW is to study the correctness of the existing division and cooperation of labor in the team. The main purpose of the self-photographs- attracting workers and employees to active participation in identifying and eliminating lost working time. Self-photography is carried out by the workers themselves, who record the amount of lost working time and the reasons for their occurrence.

- this is an observation of the elements of his work and breaks in it. It is carried out to determine the efficiency of equipment use and the time spent on its maintenance by workers of various groups. When photographing the production process, a study is simultaneously carried out of the working hours of the performers, the time of use of the equipment and its operating modes. This type of photography is sometimes called two-way observation.

There are different methods for conducting FRF: direct measurements of time, when the duration of observed time expenditure elements is recorded, and momentary observations, when the states of jobs are recorded, and the structure of time spent is established by the number of moments when the corresponding states were noted.

Depending on the purposes of labor process analysis, technical means are used: stopwatches, chronoscopes, movie cameras, television cameras and etc.

All methods for studying working time costs include the following main stages: preparation for observation, its conduct, data processing, analysis of results and preparation of proposals for improving the organization of work. The content of work at each of these stages depends on the method of studying working time costs.

2. Study of labor processes

2.1 Classification of working time costs

The purpose of classifying working time costs is to group them, which allows you to objectively analyze the feasibility of using working time in relation to performance, equipment and the production process. The classification of methods for studying working time costs by observation is presented in Fig. 1.

Figure 1 - Classification of methods for studying working time costs by observation.

In relation to the performer, all working time costs can be grouped so as to reveal not only the workload, but also the nature of the performer’s employment during the working day. According to this classification work time divided into work time and break time.

Working hours consists of the time spent on completing a production task, as well as on performing work not required by the task (excessive time). The work time associated with the implementation of a production task is divided into preparatory and final operational time (main plus auxiliary) and workplace maintenance time (technical and organizational). Work breaks can be of two types: regulated (necessary) and unregulated (superfluous).

To the preparatory-final time refers to the time required to familiarize yourself with the upcoming work, prepare for it and complete it. This time is spent once for the entire batch of processed parts or once for the entire working day. The proportion of this time spent depends on the type of production and the nature of the work performed. It reaches its greatest value in conditions of single production, where there is frequent turnover of work (detail operations) at workplaces. In mass production, the preparatory and final time is small.

The classification of working time costs for workers is presented in Fig. 2, for managers and specialists in Fig. 3.

Figure 2 - Classification of working time costs for workers

Figure 3 - Classification of working time costs for managers and specialists

Basic (technological) time represents the time during which the technological process is directly carried out.

Auxiliary time is spent on actions related to preparation for the main (technological) work. For example: time of installation and removal of the product, supply and removal of tools, starting and stopping the mechanism, selective measurements of the product, checking technological modes, etc.

Workplace service time- this is the time that should be spent by workers on caring for the workplace (mechanism, tool, device) during a given specific work and work shift.

Workplace maintenance time is spent on changing tools, adjusting and fine-tuning the mechanism during work, straightening the tool and similar actions of the worker associated with caring for the workplace during a certain specified work.

Organizational service time workplace covers the worker’s time spent caring for the workplace throughout the work shift (laying out and cleaning tools at the beginning and end of the shift, lubricating and cleaning the mechanism, cleaning the workplace).

Time of regulated breaks consists of time for rest and personal needs, as well as breaks due to the organizational and technological features of the process. Unregulated breaks in work occur mainly due to organizational or production and technical problems, due to violations of labor discipline.

2.2 Photograph of working hours

Working time photography (WPH) refers to a method of studying the labor process in order to identify the expenditure of working time during the studied period (usually an entire shift). The following tasks are solved with the help of the PDF:

identification of losses of working time, indicating their causes and the subsequent development of organizational and technical measures to eliminate losses;

designing a normal working time balance;

study of costs and compilation of the actual balance of working time by category and assessment on this basis of current standards and norms;

accumulation of materials for the development of standards for preparatory and final time, time for servicing the workplace, time for rest and personal needs;

determination of the number and standards of service for various categories main and auxiliary workers, establishing the level of use of working time and the appropriate distribution of responsibilities between foremen, foremen, technologists and other line managers.

Observations are carried out on one worker or a group of workers; accordingly, individual and group photographs of working time are distinguished. The PDF consists of four stages.

Preparation for observation consists of establishing the purpose of observation, selecting objects and the method of observation, becoming familiar with the object of observation and the system for organizing the maintenance of workplaces, preparing everything necessary for carrying out the observation (observation sheets, time devices, etc.). When conducting individual FW, observations and recordings are carried out according to the current time, when all the worker’s actions are recorded with a time stamp for the start of each next action (Table 1). In case of deviations, the observer records comments on defective records; the worker’s actions are also recorded on the observation sheet, allowing him to reveal (or hide) shortcomings in the organization of work.

Table 1 - Observation sheet for individual photographs of working hours

When processing observation data, an index is placed next to the recording of time costs in the observation sheet and the value of these costs is determined by subtracting the previous time from the subsequent one. Based on these data, a summary of the time spent by workers is compiled (Table 2). Next, the observation results are analyzed. At the same time, irrational costs and losses of working time are determined. Their reasons are established.

The percentage of operational time is determined:

percentage of operational time

K o. in = (t op / T n) 100,

where T n - observation time, min.;

percentage of lost working time dependent on workers

where t from. f - time of actual rest; t from. p - regulated time for rest and personal needs; t p.r - loss of working time allowed by the worker;

percentage of lost working time that does not depend on the worker

where t n. R. and t p.o - loss of time for production work and for organizational and technical reasons, respectively.

Lost working time is a reserve for increasing labor productivity. To determine a possible increase in labor productivity, a normal and actual balance of working time is drawn up. The normal balance is drawn up according to standards without seeing the work being performed, but the actual balance is drawn up based on photographic materials. The percentages of a possible increase in labor productivity by eliminating the loss of working time depending on the worker are established.

a 1 = (100·K p.r) / (100 - K p.r),

as well as loss of working time for organizational and technical reasons and unproductive work

a 2 = (100 K p. n) / (100 - K p. n),

Overall possible increase in labor productivity

a = a 1 + a 2.

At large quantities Observed objects take a group photograph during working hours. It uses periodic recording methods at certain, predetermined intervals. The content of preparation for observation is similar to the individual PDF, but is supplemented by specific characteristics of groups of workers, equipment and industrial buildings. In strictly observed periods and when walking around objects in order, the observer for each of them records the content of work or breaks in work with indices. At the end of the observation, a summary of the same costs for each observed object is compiled, conclusions and the development of measures are carried out similarly to individual PDFs.

Table 2 - Summary of working time costs

Conclusions and development of organizational and technical measures to eliminate extra costs time are based on a summary of time expenditures of the same name, in which for each of their categories it is indicated total time and the relationship to total time is determined. During the analysis process, actual costs are compared with standard costs, which are determined based on the design of the most effective system workplace services.

Based on a comparison of the actual and projected work organization, an action plan is developed to improve the use of working time, indicating the timing of their implementation, the expected effect, the necessary costs, sources of financing and those responsible for implementation.

2.3 Method of moment observations

If necessary, simultaneous monitoring of a large number objects use the method of instant observations, based on the application of probability theories in mathematical statistics. When studying working time costs using this method, the number of observations (moments) must be large enough to correctly characterize the phenomena being studied and ensure the desired accuracy of the results; the duration of the series of observations must be sufficient to cover the elements of work. The general formula for determining the number of moments (observations) is as follows

where is the coefficient that determines the level of probability of the observation error not exceeding the established limits; P - the probability that a worker or machine is busy performing a particular job, characterized by their workload coefficient (the proportion of time spent on performing the work under study, or the operating time of the equipment), I-P - the probability that the worker or machine is in a state of inactivity ( specific gravity interruptions in the work of a worker or downtime of a machine); - permissible relative error of observation results (usually depending on the P value).

In mass and large-scale production, they are usually satisfied with a confidence probability of 0.64, which corresponds to 2 = 2. In medium- and small-scale production, in order to obtain greater confidence in the reliability of the observation results, they proceed from a confidence probability of 0.92 ( L 2 =). Depending on the type of production, special tables have been developed to determine the number of observation moments. The duration of one round T bypass is determined by the formula

where L obx is the length of the route to bypass workplaces, m;

0.6 - average length of one step, m; 0.01 - average duration of one step, min.

Number of moments recorded per shift M" will be

where the coefficient taking into account the discrepancy in round times (deviations) is 0.5< < 0,7; m - число объектов наблюдения при одном обходе.

The number of work shifts C required for observation is determined by the formula

C n = M / M"

When an observer sequentially walks around objects, the state of each of them in this moment is recorded in the map of moment observations, the final result of observation for the shift according to the categories of time expenditure is determined by counting the number of corresponding marks (fixed moments) for each of the indices and the machine (workplace) and in total for the area with the determination of the cost structure. etc., as with FW, analyze the time spent, develop organizational and technical measures to eliminate losses of working time and determine the indicator of a possible increase in labor productivity.

Table 3 - Observation sheet of photography using the method of momentary observations

2.4 Timing

Under the timing refers to the method of studying the content of an operation, the sequence of its implementation and measuring the cost of working time to perform individual cyclically repeating main and auxiliary elements of the operation.

Purpose of timing: obtaining initial data for developing time standards for work elements; establishing time standards for individual operations; checking and clarifying time standards established by the technical calculation method; study, generalization and dissemination of rational methods and techniques for the work of advanced workers; checking the possibility of combining in time labor actions and movements not taken into account when calculating standards according to standards; synchronization of work on production lines and conveyors in order to fully load units and workers - operators.

The timing process consists of several stages.

Preparing for Timed Observation is:

justifying the choice of workplace based on the structure of the operation and its compliance with the equipment, working conditions and worker qualifications;

dividing the operation into its component elements - complex techniques, techniques or movements;

establishing factors influencing the duration of each element.

The choice of observation objects is determined by the purpose of timing. If the purpose of timekeeping is to establish or clarify time standards, then workers or teams whose performance results are at a level between the average productivity achieved by all workers and the productivity of advanced workers are usually recommended as objects of observation. It is important to take into account that with the usual timing technique, the actually established time is recorded. this area a pace of work that may not correspond to the normal intensity of work for given conditions. When conducting timekeeping for the development of standards, the objects of observation should be typical performers of this work, who have the necessary psychophysiological characteristics, qualifications and perform the operation at the required pace. If timekeeping is used to study best practices, then the object of study should be the workers using the most effective techniques and working methods. Timing can be carried out to identify the reasons for non-compliance with standards by individual workers, which makes it possible to identify phenomena that interfere with the implementation of reasonable standards and to identify erroneous standards.

This stage ends with entering the listed information and elements of the operation into the observation sheet with the establishment of fixation points.

Fixation points are sharply expressed (according to sound or visual perception) moments of the beginning and end of elements of operations. For example, fixation points can be: the touch of a hand on a tool or workpiece, a characteristic sound when the metal cutting process begins, etc.

Based on standard estimates of variation, as well as the required accuracy and reliability of timing results, a preliminary number of measurements is established. Tables and formulas are used for this. The resulting preliminary estimate of the number of measurements is refined based on the results of observations.

Time observation be reduced to measuring and recording the duration of each standardized element of the operation using time instruments (stopwatches, chronometers, special time recorders). Based on the method of conducting, a distinction is made between continuous and selective timing. With continuous timing, the current time for performing all methods of a technological operation is continuously measured. With selective timing, only the duration of individual standardized techniques is measured, regardless of their sequence. To carry out timing and subsequent data processing, a special timing and observation sheet is used. On the front side chronocards All data about the operation, equipment, tools, materials, workers are recorded, and the state of organization and maintenance of the workplace is indicated. In preparation for timing, the operation under study is divided into elements: sets of techniques, techniques, actions, movements. The degree of division of the operation depends mainly on the type of production.

Processing and analysis of observation results when timing is carried out according to the current time, they are as follows:

for each element of the operation, its duration is determined by subtracting the current time of the previous element from the current time of the given element; defective elements noted during observation are excluded from the formed time series;

For each time series, the stability coefficients K y =t max /t min are determined, where t max and t min are the maximum and minimum duration of the element execution, respectively.

The actual values of the stability coefficients of the resulting chronosequences should not exceed the standard values.

Timing series of manual work methods are less stable than series of machine-manual work. The closer the value of the stability coefficient K is to one, the higher the stability of the series.

For a stable time series, the time standard for an operation element is determined as the arithmetic mean

where t i is the particular value of the i -th duration (options) in this series; q i - repeatability of the value of the i-th option (frequency); - the number of terms (measurements) remaining in the series after its processing.

Final stage timing - analysis of results, which includes identifying unnecessary movements and actions, assessing the possibility of combining them and reducing duration. Based on the results of the analysis, the required time to complete the operation is finally established.

Conclusion

When studying labor processes, the solution of two problems is of greatest importance: determining the actual time spent on performing elements of operations (labor movements, actions, etc.); determining the structure of time spent during a work shift or part of it.

Studying the duration of the elements of operations is necessary for developing time standards, choosing the most rational labor methods, establishing the components of time standards, and analyzing the quality of standards.

Methods for studying labor processes depending on the purpose of the study: timing; photograph of working hours; photographic timing.

Timing serves to analyze labor techniques and determine the duration of repetitive elements of operations.

Photo of working hours ( FRF) is used to establish the structure of its costs during a work shift or part thereof. If in case of timing the object of study, as a rule, is the elements of operational time for a specific type of product, then in case of time-lapse the time spent on all types of work and breaks that were observed during a certain period of time is recorded.

Photochronometry used to simultaneously determine the structure of time costs and duration of individual elements of a production operation.

Forms and methods of conducting timekeeping, photographs of working time, phototiming, depending on the objectives of the study and the characteristics of labor processes:

Timing can be carried out in three ways: continuous (according to the current time), selective (necessary when studying non-cyclical elements of operations, as well as when conducting additional observations on individual elements to replace those rejected during the processing of time-keeping observations) and cyclic, when it is difficult to measure with sufficient accuracy the time spent on separate elements of the operation that have a short duration (3-5 seconds.

Photos of working hours differ according to the observed objects. This is how the following can be carried out: photography of the use of workers’ time (individual, group, self-photography); photograph of equipment operation time; photograph of the production process.

1. When individual photography working time observer studies the time use of one employee during a work shift or other period of time.

2. Group photo of working hours carried out in cases where work is performed by several workers, in particular in collective labor organization. One of the important tasks of this type of PDF is, for example, to study the correctness of the existing division and cooperation of labor in a team.

3. Main purpose self-photographs is to involve staff in active participation in identifying and eliminating lost working time. Self-photography is carried out by the workers themselves, who record the amount of lost working time and the reasons for their occurrence.

4. Photo of equipment usage time is an observation of elements of his work and breaks in it. It is carried out with the aim of obtaining initial data to determine or clarify the equipment maintenance time by one worker or a group of them.

5. When production process photos At the same time, a study is carried out of the working hours of performers, the time of use of equipment and its operating modes. This type of photography is sometimes called two-way observation, i.e. the monitoring process can be carried out by two observers: one watches the workers, the other watches the equipment.

All methods for studying working time costs include the following main stages: preparation for observation, its conduct, data processing, analysis of results and preparation of proposals for improving the organization of work.

Based on a summary of costs of the same name, actual and standard balances of working time are compiled; the possible increase in labor productivity is calculated; measures are being designed to eliminate losses and waste of working time.

Bibliography

1. Abakumov, V.V. Fundamentals of management. Tutorial/ V.V. Abakumov, A.A. Golubev, V.P. Kustarev, V.I. Podlesnykh and others; Ed. IN AND. Podlesnykh. - M.: Business press, 2006. - 240 p.

2. Avrashkov, L.Ya. Enterprise economics / L.Ya. Avrashkov, V.V. Adamchuk, O.V. Antonova and others - M.: UNITI, 2001. - 455 p.

3. Genkin, B.M. Organization, regulation and remuneration of labor industrial enterprises. Textbook / B.M. Genkin. - M.: Publishing house: "NORMA", 2003. - 400 p.

4. Egorshin, A.P. Organization of personnel work. Textbook / A.P. Egorshin, A.K. Zaitsev. - M: INFRA-M, 2008. - 320 p.

5. Kobets, E.A. Organization, standardization and remuneration of labor at industry enterprises / E.A. Kobets, M.N. Korsakov. - Taganrog: TRTU Publishing House, 2006. - 79 p.

Abakumov V.V. Fundamentals of management. Textbook / V.V. Abakumov, A.A. Golubev, V.P. Kustarev, V.I. Podlesnykh and others; Ed. IN AND. Podlesnykh.- M.: Business press, 2006. – P.175.

Introduction

2. Study of labor processes

2.1 Classification of working time costs

2.2 Photograph of working hours

2.3 Method of moment observations

2.4 Timing

Conclusion

Bibliography

Introduction

The relevance of this topic is due to the search for new approaches to labor management of enterprise personnel in modern conditions; the need to improve professional levels in order to change traditional management systems of social and labor relations, personnel and production, using more effective forms and methods of management. Labor problems affect the interests of all categories and groups of the population in matters of organization and regulation of labor, its payment and other issues considered by economics and the sociology of labor.

When organizing labor, two tasks related to the study of labor processes are of greatest importance:

1) determination of the actual time spent on performing elements of operations (labor movements, actions, techniques, etc.);

2) establishing the structure of time spent during a work shift or part of it.

The work consists of an introduction, two parts, a conclusion and a list of references.

1. General characteristics of methods for studying labor processes

It is possible to rationally design the labor process and ensure the validity of labor standards only on the basis of initial information and special research. The main goals of such studies are:

analysis of the operation structure and working time costs;

obtaining information about factors affecting working time costs;

determination of the magnitude and causes of losses and waste of working time;

obtaining data for the development of norms and standards;

assessment of the quality of applied norms and standards, reasons for non-compliance (over-fulfillment) of norms;

comparative assessment of the rationality of the techniques and methods of work used;

obtaining initial data for the development of instructional and technological maps.

The main object of rationing is the production operation.

A) Labor movement. It is the initial element of the labor process and represents one-time actions of the worker.

b) Working technique. It is a complete set of worker actions, characterized by a purpose.

V) Set of techniques. A group of techniques combined according to technological characteristics.

G) Passage - repeated actions carried out on the same object of labor at one workplace.

d) Transition- part of the surface treatment operation with the same tool used and equipment setup. There are several transitions in an operation - roughing, finishing, trimming, etc.

identify and eliminate losses of working time due to more complete use of reserves of equipment, technology, organization of labor and production;

achieve an optimal relationship between man and machine in the workplace;

generalize and specify the main directions for improving the organization of labor and production, as well as mobilize workers’ initiatives to increase production efficiency.

The objects of research on working time costs can be:

all types of costs and losses of working time, highlighting elements of operations and operational time;

preparatory and final time;

working hours for servicing workplaces;

certain types of lost working time;

time to complete individual elements of operations.

For example, when studying the work process of a team, the quality of products, the employment of each member of the team, and the degree of use of equipment are recorded. Such a comprehensive study of working time costs is one of the main means of identifying and using reserves for increasing labor productivity through further compaction of the working day, better use of technology, improvement of technology, organization of labor and production.

To obtain the necessary information at minimal cost, it is very important to justify the number of observations. Methods for studying labor processes can be classified according to: the purpose of the study, the number of objects observed, the method of conducting observation, the form of recording its data, etc. Depending on the purposes and technique of observation, the following are distinguished: basic methods: photograph of working hours, method of momentary observations, timing.

Timing serves to analyze labor techniques and determine the duration of repetitive elements of operations. Working Time Photography (FWP) used to establish the structure of its costs during a work shift or part of it. The term “photography” quite accurately reflects the essence of this method. If in case of timing the object of study, as a rule, is the elements of operational time for a specific type of product, then in case of FW the time spent on all types of work and breaks that were observed during a certain period of time is recorded. In this case, the elements of operational time are allocated enlarged (before techniques or complexes of techniques).

Methods for studying labor processes

Most problems related to HOT are solved based on information obtained from studies of labor processes. Thus, through the study of labor, three tasks are solved:

1) determination of existing labor costs for performing operations, types of work or their constituent elements(labor movements, labor actions, labor practices);

2) identifying the structure of working time costs during the working day or part of it and assessing its components from the point of view of their rationality and necessity;

3. Creation of a basis for long-term calculations of working time costs - labor rationing. To measure labor, various methods and types of observations are used (Table 2)

table 2

Classification of methods for studying labor processes

Continuous observation method used for photographs of working hours, when a preliminary study of the content of work is necessary. Advantages of the continuous observation method: detailed study of the labor process and the use of equipment; obtaining data in absolute terms (s, min, h) and their high reliability; establishing actual working hours for the entire observation period; obtaining information about the sequence of individual work elements; the possibility of involving workers themselves in research. Disadvantages of the continuous observation method: observations are lengthy and labor-intensive, data processing is quite complex; observation time is limited, observation cannot be interrupted; one observer, as a rule, is not able to provide high-quality observation and recording of results for more than 3–4 objects; The reliability of the results is affected by the constant presence of an observer.

Periodic observation method, is used for group and route photography and allows you to obtain data on the number of cases of occurrence of certain costs, loss of working time or equipment downtime. Monitoring is carried out simultaneously during work large number workers or pieces of equipment. Sample observation method used mainly in timing, when individual elements of an operation are studied. It is most widely used in conditions of multi-machine work organization. Cyclic observation method– a type of selective observation method – used only for timing, when it is necessary to measure the time of performing techniques (actions or movements) with a very short duration, and therefore it is impossible in the usual ways observations (using stopwatches) to accurately record the time they were completed. Here, time measurements are made in groups of individual techniques.

Momentary Observation Method is a study of labor time, workload, and equipment use over time based on sample observations taken at random points. The necessary data on the composition and amount of working time spent using this method are obtained through a series of sudden, short and irregular observations. After establishing the number of cases of recurrence individual species the costs of working time, work or equipment downtime, the specific weights and absolute values of the time spent on an operation are determined. In order for the observation results to be close to the actual working time spent, using this method, the following conditions must be met:

1) each observation should be so short as to cover only one object being studied;

2) the period of conducting a series of observations should be long enough to cover all elements of the work;

3) observations of certain working time expenditures must be random and equally possible;

4) the sample size (i.e., the number of observations) must be large enough to correctly characterize the phenomena being studied and ensure the desired accuracy of the results. The volume of observations is determined by the formula:

where M is the sample size (the number of measurements per unit of observation that need to be recorded) or the number of momentary observations, units; – coefficient of working time use, determined according to data from previously conducted observations, share; – share of breaks and downtime, shares; p – the permissible value of the relative error of the observation results is 0.03–0.1 parts; – reliability coefficient associated with the confidence probability of the observation error not exceeding the established limits of 0.84–0.95 shares; with a further increase in reliability, the number of observations increases sharply.

Advantages of Momentary Observation: one researcher can observe an almost unlimited number of objects; the reliability of the observation will not be affected if it is interrupted and then resumed; labor intensity is 5–10 times less than with the continuous observation method; there is no psychological impact on the object of observation. Disadvantages of Momentary Observation: the result is the averaged data; there is no way to directly record the causes of downtime, losses, and waste of time; there is no data on the consistency and rationality of performing techniques and operations.

Observation methods are divided into the following types:

1) visual observation without measuring the work time spent by the performer on individual elements of the labor process. It is used during initial acquaintance with the labor process to establish the content of labor, the list and sequence of operations, and to draw up a plan for studying experience;

2) observation, accompanied by measurements of the duration of execution of individual or all elements of the labor process using watches, stopwatches, chronoscopes and other means;

3) surveillance using television cameras. It makes it possible to increase the efficiency of monitoring, carry it out without distracting the employee’s attention, and quickly view different workplaces;

4) conversation with an employee, interview, questionnaire. The information obtained allows us to supplement and clarify visual observation data, and to deeply analyze the factors that positively and negatively influence the course of the labor process.

5) observation using recording and fixing instruments and apparatus: cameras, movie cameras, video cameras, chronographs, momentographs, oscilloscopes, etc. Right choice technical means for studying the labor process allows you to carry out research with the necessary accuracy and with minimal labor intensity.

Depending on the purpose and object of observation, different methods for studying working time costs–timing and photograph of the working day.

Timing is a method of studying labor time costs by observing and measuring individual repetitive elements of an operation. When timing, the object of study is a production operation or its elements performed by a worker or their group at a specific workplace. Timing is carried out for the following purposes: 1) establishing time standards for the operation; 2) verification and clarification of applied standards; 3) studying the methods and techniques of advanced workers; 4) obtaining initial data for developing time standards for elements of manual and machine-manual work.

Timing may be continuous, selective and cyclic. When conducting continuous time observations At the current time, all work elements are examined in the order in which they are completed. Selective timing used to study individual elements of operations, regardless of their sequence. In cases where it is difficult to measure with sufficient accuracy the time spent on individual elements of an operation that have a short duration (3–5 s), it is used cyclic timing. It lies in the fact that successive techniques are combined into groups with different compositions of the elements being studied. Based on measurements of the duration of execution of groups of elements, the duration of each element of the operation included in them is determined. So, if there are techniques a, b, c, then they can be combined into three groups: a + b = A, a + c = B, b + c = C. Next, the execution time of each such group of techniques is determined by observation (A , B, C). As a result, we get three equations with unknowns a, b and c. After solving them, the execution time of individual elements is found.

In timekeeping, digital recording is most widely used. In some cases, the graphic record is supplemented with digital and index marks (combined record). When conducting observations in order to identify the best, as well as unnecessary and irrationally performed actions and movements of a worker, photography, filming, and oscillographic recording are used. Timing can be carried out using various kinds of stopwatches, and then the measurement results are counted visually by the observer according to the indications of the stopwatch hand and entered by him into the observation card. In other cases, graphic instruments such as chronographs and special photographic and film equipment are used. In this case, the observer is freed from reading and recording time readings, since the chronograph shows the total time for each element of the operation, the total number of measurements and gives a chronogram that records the duration of individual costs, their sequence and any overlap in time.

Timing should be carried out 50–60 minutes after the start of work, i.e. at the end of the working period. It is also recommended to take measurements 1.5–2.0 hours before the end of work. Compliance with these conditions makes it possible to more accurately determine the labor costs of a worker or their group, because the observation covers shift periods with an average pace of work, which are determined by the curve of changes in performance. It is not practical to conduct time-keeping observations at the beginning and end of a shift. It is also necessary to avoid observations on the first and last day of the work week. When determining the time for conducting timing observations, it is necessary to take into account changes not only in the pace of work of the same worker due to workload and fatigue, but also in the organizational and technical conditions of the production process.

The choice of observation object during timing is determined by the purpose of the study.

1. To study and generalize the best experience, observations are made of the best workers. For this purpose, the best practices of other workers are used and analyzed.

2. To implement and eliminate the causes of poor performance, observations of lagging workers are analyzed.

3. To develop production (time) standards, average workers are selected as the object of observation. By methodological recommendations, such a choice is made simply based on data on the worker’s fulfillment of production standards for the month. Workers who do not meet production standards are not taken into account. For the remaining workers, the arithmetic average level of compliance with standards is calculated. The objects of observation are workers who have a level of compliance with standards close to this level. The disadvantage of this technique is the low accuracy of the result, therefore it is used for single and small-scale production, where, with reduced requirements for the accuracy of standards, simplicity and efficiency of their development are necessary. In stable production, it is more expedient to select workers with an average pace of work based on data from preliminary moment-to-moment observations.

Having determined the object of observation, they make up detailed description operations, which are entered into a special document - chronocard. On its front side, all data about the operation, equipment, tools, materials, workers are recorded, and the state of organization and maintenance of the workplace is indicated. In preparation for timing, the operation under study is divided into elements: sets of techniques, techniques, actions, movements. The degree of division of the operation depends mainly on the type of production. After dividing the operation into elements, their boundaries are determined, determined by fixing points– sharply expressed (according to sound or visual perception) moments of the beginning and end of elements of operations. For example, fixation points can be: the touch of a hand on a tool or workpiece, a characteristic sound when the metal cutting process begins, etc.

With selective timing, the starting and ending fixing points are set for each element of the operation. In preparation for timing, the required number of observations is determined. In this case we are talking about a preliminary assessment. This is due to the fact that the duration of an operation element is a random variable. From mathematical statistics it is known that the number of observations required to obtain the average value of a random variable depends on the variation of its values, determined by variance or other indicators. A sufficiently accurate estimate of variation can be established only from observational data. Therefore, at the stage of preparation for timing, standard estimates of variation are used for various production conditions.

The simplest of these estimates is the stability coefficient, which is determined by the ratio of the maximum duration of the observed element of operations:

It should be noted that the stability coefficient is a very rough estimate of the variation, since it takes into account the ratio of only the extreme values of the variation series. To increase the validity of timing results, it is advisable to use more accurate statistical estimates (variance, mean linear deviation, etc.).

Based on standard estimates of variation, as well as the required accuracy and reliability of timing results, a preliminary number of measurements is established. The resulting preliminary estimate of the number of measurements is refined based on the results of observations. After receiving the required number of measurements, the observation data is processed. For each element of the operation, a number of values for its duration are obtained, i.e. time series.

Stages of time series processing.

– The first stage of its processing is the elimination of defective measurements, which are identified primarily on the basis of entries in the observation sheet about deviations from normal operation.

– The second stage is time series analysis. Typically, for this purpose, actual stability coefficients are used, calculated using the formula for , and their values are compared with standard ones. If the actual value is not greater than the normative one, then the time series is considered stable; otherwise, it is recommended to exclude the maximum value of the duration of the operation elements and then calculate again. It should be noted that the exclusion of defective measurements based on stability coefficients cannot be considered sufficiently justified. It is considered more correct to use the methods of mathematical statistics (based on the assessment of the probabilities of obtaining sharply prominent elements of the chronosequence).

– The third stage – after eliminating defective measurements, the average duration of each element of the operation is found. It is usually defined as average arithmetic values time series corresponding to normal operating conditions. When justifying standard values for the duration of elements of an operation based on timing data, it is necessary to take into account the distribution law of the random variable under study. Its character is established primarily based on the physical essence of the observed process. So, if deviations from the average value are equally likely both upward and downward, the distribution law can be considered normal. The hypothesis about the distribution law is tested using statistical criteria based on observational data. Research shows that random variables, observed during timing, are usually characterized by a normal distribution law or laws close to it.

– The fourth stage of timing is analysis of the results, which includes identifying unnecessary movements and actions, assessing the possibility of combining them and reducing the duration. Based on the results of the analysis, the required time to complete the operation is finally established.

Under working time photograph (FW) refers to the type of study of working time by observing and measuring all costs without exception during the working day or a separate part of it. Time photography can be used for a variety of purposes.

1) to determine the rational use of working time, identify losses of working time for various reasons and develop organizational and technical measures to eliminate such losses, improve the organization of production and labor. In this case, the FW should be carried out without prior intervention in the existing organization of labor and maintenance of the workplace, and the object of observation should be all workers employed in this area;

2) to study and generalize best production practices in the distribution of working time during a shift and establish a more rational balance of working time. In this case, it is advisable to observe the work of advanced production workers;

3) to compare the actual workload of the worker with his possible workload when carrying out any organizational and technical activities. In this case, the FW is carried out before the implementation of the planned activities, but after the loss of working time has been eliminated.

Main stages of FR:

1) preparation of photographs;

2) conducting FRF;

3) processing of observation results;

4) analysis of results and development of measures to improve the use of working time.

On preparatory stage The purpose of photography is determined (identification of lost working time, development of standards, etc.) and the object of observation is selected in accordance with the goal. Next, you should carefully study the technological process, the organization of the workplace, the procedure for its maintenance, the division and cooperation of labor between different groups of workers, choose a place from which it is convenient to observe the worker without disturbing him, and inform him about the purposes of photography. When preparing to take photographs of a working day, it is also necessary to determine fixation points - clearly defined moments of the beginning and end of the operation.

Depending on the observed object, the PDF can be of three types.

1) photograph of the use of workers’ working time;

2) photography of the time of use of the equipment, this is monitoring the operation of the equipment and recording breaks in it. It is carried out in order to determine the efficiency of use of the equipment and the time spent on its maintenance by workers of various groups;

3) photography of the production process, used in hardware (thermal, galvanic, foundry) processes. This is a simultaneous study of the working time of performers, the time of use of equipment and its operating modes.

Working time photography can be done in two ways: continuous observations and momentary observations. A photograph of a working day (working time) can be individual when observing an individual worker; group when observing several workers; mass when studying the working time costs of a large part of workers; self-photography when an employee personally fills out an observation sheet. Common to all types of working day photography is the sequential recording in the observation sheet of all the performer’s actions and breaks in work in chronological order, indicating the current start time of each type of time expenditure.

Widespread individual photograph of working hours, in which the object of observation is one employee at a certain workplace. When processing observation data in the observation sheet, their index is put against the record of time costs and by subtracting the previous time from the subsequent one, the value of these costs is determined. Based on this data, a summary of the worker's time spent is compiled. Next, the observation results are analyzed. At the same time, irrational costs and losses of working time are determined, and their causes are established. In the process of analysis, the actual costs of preparatory and final time, organizational and technical maintenance time are compared with the standard ones, which are determined on the basis of the design of the most effective workplace maintenance system. The required time for rest and personal needs per shift is established on the basis of industry standards for given working conditions and the design of a rational work and rest regime. After this, the actual and standard balance of working time is compiled. Based on them, the shares of operational time, maintenance time, loss time for various reasons, etc. can be established.

The methodology for conducting group, mass and route photography of working hours is basically similar to individual photography. However, continuous observation is labor-intensive and requires a large number of observers. It is possible to carry out PDF using the method of momentary observations. In contrast to the previously discussed method, when conducting momentary observations, continuous recording of individual elements of working time costs is replaced by selective recording. Observations with this method are carried out randomly, so their number should be sufficient to obtain a reliable idea of the working time used. The number of rounds is determined by division total number observations (M), by the number of people or pieces of equipment that must be inspected (N):

The duration of one walk is determined either by direct measurements, or by calculation based on tables of microelement standards, where it is given that one step (600 mm) takes 0.01 minutes in time. The observation route must be chosen so that all observed workers or equipment can be seen one by one. It should be as short as possible and, if possible, exclude idle transitions. When determining it, it is necessary to establish fixing points, i.e. those places along the observer’s route where the recording of what is happening at the workplace will be made. To determine the duration of observations, a trial walk along the intended route is carried out. Knowing this time and the number of rounds, the total time required to conduct the observation is determined. The main requirement of momentary observations is that the recording of certain types of working time costs be random and equally possible. In this regard, it is very important to choose the right moments for conducting observations. Compliance with the condition that the number of rounds in each hour of work is the same and the start times of rounds in the same hours of work on different observation days do not coincide, ensures the same opportunity to observe all elements of working time costs. This condition is especially important to observe in those areas of production where there is synchronization of operations, the rhythm and tact of work are determined. The observation technique is very simple. Consistently moving from one workplace to another, the observer at each fixation point notes what he sees, without recording at what point in time this state was noted and how long it lasted. This requires compliance with some rules.

1. Each round must begin exactly at the appointed time, determined by the round schedule.

2. The walk must be carried out along the route at a uniform pace, without speeding up or slowing down the walk; the observer must record what is happening at the workplace when he is at the fixing point for these workers, and not from another place; the volume of observations (number of rounds) provided for per unit of time (hour, shift) should be strictly carried out.

Having completed the entire volume of observations, the received data is processed, which begins with counting the number of moments for each observed element. Then the specific gravity (in percentage) of each element is determined. Based on these data, the actual working time balance is compiled. Then a balance of time in minutes is compiled, taking into account (as a percentage) their share in the duration of the shift. The choice of the PDF method depends on the nature of the processes being studied, the stated purpose of the research, the effort expended, the time budget and financial resources.

Photochronometry combines timekeeping methods to study operational time and working time photography to study other elements of working time.

Bibliography

1. Egorshin A.P. Organization of personnel labor: textbook / A.P. Egorshin, A.K. Zaitsev. – M.: Infra-M, 2009. – 320 p.

2. Lezhenkina T. I. Scientific organization of personnel labor: textbook. allowance / T.I. Lezhenkina. – M.: Market DS, 2010. – 232 p.

3. Ostapenko Yu.M. Economics and sociology of labor in questions and answers: textbook. allowance / Yu.M. Ostapenko. – M.: INFRA-M, 2006. – 268 p.

4. Labor economics ( social and labor relations): textbook / ed. ON THE. Volgina, Yu.G. Odegova. – M.: Exam, 2006. – 736 p.

Control questions:

1. What is labor and work activity? What are characteristic properties labor?

2. What types of labor is divided into? By what criteria?

3. What is meant by division of labor and what are its main forms?

4. What boundaries and criteria for the division of labor do you know?

5. How does labor productivity depend on the level of its content?

6. What is meant by labor cooperation? What types and forms of cooperation exist?

7. What is the production process? What processes does it consist of?

8. What is a technological process? What is the classification of technological processes?

9. What is the labor process? What is the classification of labor processes?

10. Define operation, production operation and complex of production operations?

11. What elements are technological and labor operations divided into?

12. What are the principles of organizing labor movements?

13. List and describe the essence of methods for studying labor processes.

14. What is timing and what is the essence of this method of studying working time costs?

15. What is working time photography and what is the essence of this method of studying working time costs?

Labor processes and methods of their research. Methods for studying labor processes and working time costs

Introduction

1. General characteristics of methods for studying labor processes

2. Study of labor processes

2.1 Classification of working time costs

2.2 Photograph of working hours

2.3 Method of moment observations

2.4 Timing

Conclusion

Bibliography

Introduction

1. General characteristics of methods for studying labor processes

Methods for studying labor processes

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