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We wanted to study and optimize work at all times. With the improvement of technologies and the conclusion of research, there are four main methods for evaluating working time.

Introduction

The desire to identify working time dates back to over 200 years. Thinkers like Leonard da Vinci or Jean-Rodolphe Perront studied the problems of task cutting, elementary operations studies and perfection in working methods to increase efficiency1.

At the beginning of The twentieth century, the chronometer conquered the industrial workshops through the Office of methods. It is the symbol of Taylorism and the organization of work. It is Frederick Winslow Taylor (1856-1915) who is on the initiative to time work2. As a simple machinist and then a team leader at the Midvale Steel Company, it was in the years 1880-1881 that he realized the need to measure the ” Fair working day “. He worked on this subject accompanied by H. L. Gantt and F. A. Halsey. Taylor named his work ” Scientific Management “, an expression he preferred to the ” Taylor system “. In his logic of thinking, Taylor says that ” the public cannot tolerate the kind of employer who has eyes only on dividends, who refuse to share the work and whips the workers to push them to work more with less pay .” Nevertheless, Taylor also believes that the ” public cannot tolerate the tyranny of workers who are increasingly demanding increases while working less hours and less efficiently3. His technique was to do the time study with a worker above average. Also, at that time, working times were determined for the execution of tasks, and this was used as a basis for setting salaries. Step by step, the timing is generalized and goes so far as to break down each of the elementary movements.

Then, Charles Eugène Bedaux (1887-1944), a French immigrant to the United States, improved the idea of measuring time. He introduced the notion of ” rate ” of performance of the worker. His idea was to introduce the notion of rest in time studies. He identified a unit of work, which he called B (b being derived from Bedaux) and defined it as ” a fraction of a minute of work plus a fraction of a minute of rest, constituting a unit together, but varying in proportion depending on the nature of the constraint4. Thus, a rate of 60B per hour was applied as a standard at the time measured to establish standard time. A 80B rate is the optimal rate.

The first to have widely used these methods of measuring time is Henry Ford. Fascinated by efficiency in production, he applied Taylor’s principles rigorously. He created the first lines of assembly in 1913 and introduced the notions of standards in work, design…

Then it will be after the Second World War that more sophisticated methods appeared. They decompose both plant and laboratory tasks and take into account a ” human ” factor5.

All these techniques are now widespread. They are used to define the prices, the costs, to motivate, to compare the design possibilities, to make the schedules or even to appreciate the performance.

Techniques for studying time

Generally speaking, time identification techniques can be grouped into two families:

Time Study

Time Study is the historical technique of working time research. It is defined by the Industrial Engineering Technology Standard as ” the technique of taking care to measure tasks with a suitable instrument, and adjusting the variability of normal effort and rhythm by taking into account elements such as Delays, fatigue… ».

It consists of recording time to do a job by noting the conditions in which the work was done. Depending on these parameters, an analysis can be done to define the time needed and to identify a performance rate. It is generally used for:

  • Short or long repetitive tasks
  • A lot of work is done in masked time
  • Control tasks are performed in the cycle time

Work sampling

Work Sampling, the principle is to carry out measurements in time even if the work is not carried out in good conditions (fatigue…) and to perform calculations (average, standard deviation…) on all these measures to identify a Average time of operations, fatigue coefficients… This technique is used mainly in the following cases:

  • There is a high variability in cycle times.
  • To identify the percentage took to carry out the different activities and put forward the use of machines, tools and space.
  • When you cannot use the Chrono-analysis studies.

Predetermined Time method

The predetermined Motion time System (PMTS) methods have their origins in the late nineteenth and early twentieth centuries. Long opposite, it will be Frank Gilbreth, Mason Training, the man of the analysis of the movements, and Frederick Winslow Taylor, the man of time measurement, who began to work predetermination times6. Then it will be A. B. Segur who developed the first predetermined time method under the name of MTA (Motion Time Analysis) in 1926. Following these early work, many tools could be created7 :

  • 1928: Motion Time Survey in 1928 by General Electric
  • 1934: Work Factor by J. H. Quick, Duncan and Malcolm
  • 1940: Engstrom System by Engstrom and General Electric
  • 1944:400 System by the Western Electric
  • 1948: MTM 1 by H. B. Maynard
  • 1950: Standard Time methods by General Electric
  • 1951: Basic Motion Time Study by J.D. Woods and Gordon
  • 1954: Polymentional Motion Time DMT by General Electric
  • 1965: MTM 2 by H. B. Maynard
  • 1966: MODular Arrangement of predetermined Time Standards by G. C. Hyde
  • Years 1980: BasicMOST, most and maximost, Maynard Operation Sequence Technique, by K. B. Zandin
  • From 1975 to 1984: MTM 3, MTM UAS, MTM MEK, MTM SAM…

These methods are particularly used in the following cases:

  • The work is performed only by an operator (no automatic operation).
  • For short-or medium-cycle time operations.
  • When it is necessary to ” predict ” The operating time (in the process design phases for example).
  • When other techniques are controversial.

How to choose the method of predetermination of time?

MTM1

MTM2

MTM3

BasicMOST

The most

The most

Number of MHC analyzed per hour8

300

1000

3000

12000

4000

25000

Level of detail

+++

0

0

+

Comment

The MTM1 is undoubtedly the most known and recognized PMTS tool.

This is the heaviest version todescribe operations in the most accurate way possible.

Version more light than the MTM1, it will describe with a level of accuracy of 95% the operations of more than 3 hours

Version lighter than the 2, it aims to reduce the time of analysis.

It will be used for low-repetitive operations where measurement accuracy is not important.

Used for repeated sequences between 150 and 1500 times per week.

The duration of the operation is 30 seconds to 10 minutes.

Used to describe repeated operations more than 1500 times a week.

The duration of the operation is from 2 sec to 30 sec maximum.

Used to describe repeated operations less than 150 times per week.

The duration of the operation is from ten minutes to several hours.

 

Standard data

Standard Data is based on all historically capitalized data (graphs, time data tables…) or obtained using time predetermination techniques. It is designed to identify a mathematical formula for calculating the time of operations in advance of production. This technique is used when:

  • Work operations are similar and in short or long cycle times.
  • When the technique of Chrono analysis is controversial.
  • When the standard data is no longer up to date.

Comparing methods

Technical by Direct Observations

Technique by indirect measures

Time study

Work sampling

Time Predetermination

Standard data

Benefits

Allows the analyst to see the whole cycle and thus identify sources of progress.

The only way to measure current actual time to perform a task.

Quick to identify a first time base.

Relatively simple to implement and explain.

Quickly provided values for machine-related operations.

Eliminates the problem of the need to make constant observations or over a long period of time.

Represents the average regardless of the conditions.

Ideally suited for studies related to machine operations.

Can be used with a performance rate.

Force to be precise in the analysis.

Allows you to compare different methods to perform a new task.

Encourages the simplification of movements.

Eliminates the need for a performance rate.

Allows to establish time in advance of production.

Safe and reliable method.

Allows you to update the time data easily according to the method changes.

Allows you to measure even times on small movements.

Set a standard language for all operations.

Gives an average performance rate.

Allows to establish time in advance of production.

Safe and reliable method.

Allows you to set standards quickly and at low cost.

Allows you to update the time data easily according to the method changes.

Disadvantages

Requires a rate of performance based on the skill of the operator and the effort.

Requires many observations on several operators.

Low performance on non-repetitive operations.

Requires one person per operator to perform the analysis.

is based on the assumption that the operator uses an acceptable and standard working method.

Requires an analysis of many types of work.

Depends on the accuracy of the task description.

Requires training time.

More complex to explain to the operational.

Requires a lot of time in the analysis.

Requires time studys or standard times for “machine” times.

High cost application to establish the first version.

Unreliable to see the small variations in the method change.

Requires good analyst skills for complex formulas.

Difficult to explain to the operational.

Source

1 – A. Bett, P. S. Brandon (2006) – Management, quality, and economics in building

2 – S. L. Macey (2010) – The Dynamics of Progress: time, methods and measure

3 – F. W. Taylor (1911) – The Principles of scientific management

4 – C. E. Bedaux (1928) – Bedaux measure Labour

5 – L. Boltanski (1982) – Frameworks: The formation of a social group

6 – D. W. Karger, F. H. BAYHA (1975) – Rational Measurement of work – MTM and predetermined time systems

7 – G. Caragno, H. Fisher (2005) – MTM – First time right

8-K. B. Zandin (2003)-MOST Work Measurement Systems

G. Salvendy (2001) – Handbook of Industrial engineering: Technology and Operations management

I. A. Salih, O. Duffuaa, D. Raouf, J. D. Campbell (1999) – Planning and control of maintenance system: Modeling and analysis

S. Kreis (1992) – The Diffusion of scientific management: the Bedaux company in America and Britain, 1926 – 1945

D. Nielson (1992) – A Mental Revolution: scientific Management since Taylor

Y. Levant, M. Nikitin (2006) – was Bedaux really a utopian socialist

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