Time study

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Professional time recording device

The term study or time of recording is, according to REFA a method of time determination , and describes the determination of target times by measuring and evaluating actual times by means of a time recording device . The most common method in German-speaking countries is the time study based on the REFA methodology .

The origins of the term study lie in the Scientific Management by Frederick Taylor . Through the work of Frank Bunker Gilbreth and his wife Lillian , they were systematized primarily with movement studies. Charles Bedaux contributed to the systematic of recovery and distribution times .

Structure of the types of process

REFA structure of the types of processes for humans

To perform a time recording, the work processes of people and equipment are divided into different types of process (see: Time per unit ).

On the first level these are:

  • In use:
    people or equipment are available to carry out work tasks.
  • Out of work:
    Long-term work during working hours is not possible, e.g. illness, vacation; or the company cannot employ them because of a lack of orders.
  • Company holidays :
    Are statutory, collectively agreed or operationally agreed work breaks.
  • Not recognizable:
    This class includes processes, the type of which cannot be determined.

In a further step, there is only a subdivision of the workers in action . The main activity or main use serves the planned, immediate fulfillment of the work task and is oriented towards the processing of the objects. Secondary activities or secondary uses serve only indirectly to fulfill the work task, such as retrofitting machines, bringing objects up. The occurrence and sequence of additional activities is unpredictable and therefore cannot be determined in advance, e.g. malfunctions, repairs. In the case of interruptions , a distinction is made between process-related, disruption-related, recreational or personal-related.

Time determination through time study

Traditional, mechanical "REFA stopwatch" in HM graduation in front of a time sheet

REFA has developed a standard program with the following main steps to determine the default times .

  1. Definition of the purpose of the time recording. The intended use determines the care and accuracy to be applied in the subsequent study.
  2. Description of the work to be measured: A description of the work system is made so precise that a trained work organizer could restore comparable working conditions. The work task to be carried out, the working procedure and the working method used must be precisely specified using the above-mentioned structure. It is also determined which activities belong to the work and into which work steps the process can be divided.
  3. Carry out time recording: divide the process into process sections and describe them. Definition of measuring points , which indicate the beginning and the end of the process sections. Record reference quantities and influencing factors . The actual times measured are documented in the REFA time recording sheet in the form of a log and then evaluated.
  4. Assessment of performance level : the measured performance is compared with a reference performance, the so-called REFA normal performance , even during the recording . This is characterized by the fact that it can be provided by every experienced and fully integrated employee on a permanent basis and as the average performance of a shift, and is used to determine the target time for performing a work.
  5. Statistical evaluation of the determined times for validity. Since the times measured in a time recording always scatter, the extent of the scatter is determined. If it exceeds a specified value, either more times have to be taken or a more stable workflow has to be achieved through work design .
  6. Calculation of the target times for the process sections and summation to the basic time for the work process of a unit.
  7. As far as necessary: ​​determination of recovery times .
  8. Determination of the distribution times : Since the duration of the distribution times depends on personal needs or machine malfunctions, they are determined with the help of a distribution time recording or statistical methods such as multi-snapshots are estimated. Many collective agreements contain blanket values ​​for personal and factual distribution times to be applied. In such cases they are negotiated.
  9. Determination of any other time allowances.
  10. Calculation of the default time as time per unit : The basic, recovery and distribution times related to a unit are added.

Time studies can be carried out based on individually specified tasks, but also systematically to obtain time modules for the development of a plan time catalog and to obtain a database for comparison and estimation .

Advantages and disadvantages

advantages

  • Information accuracy is statistically secured
  • Objectivity of the information obtained
  • Shows potential for savings

disadvantage

  • Mental activities cannot be observed
  • High effort for recording and evaluation
  • Employees are exposed to direct external observation

Conditions of use

Since this is a very complex method of determining time, it should rather be used for frequently recurring material processes. Typically, the work processes should be able to be broken down into individual steps in order to be able to chronologically record all processes as precisely as possible.

Since the employees are exposed to direct external observation, they must be informed in advance and involved in the process so that the highest possible level of acceptance among all those involved is guaranteed.

Alternative timing methods

Timing methods

The best known techniques of time determination besides time recording are:

bibliography

Web links

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  1. ↑ a b REFA Association for Work Studies and Business Organization e. V. (Hrsg.): Methodology of work studies: Part 2 data determination . Munich: Hanser, 1978. - ISBN 3-446-12704-6 . P. 81.
  2. ^ Hopp, Wallace J .: Factory Physics: foundations of manufacturing management. 2nd ed. New York: McGraw-Hill Higher Education, 2000. - ISBN 0-256-24795-1 . P. 31.
  3. ↑ REFA Association for Work Studies and Business Organization e. V. (Hrsg.): REFA-Lexikon company organization, work study, planning and control . Munich: Hanser, 2011. - ISBN 978-3-446-42821-8 . P. 121