Methods-time measurement
Encyclopedia
Methods-Time Measurement (MTM) is a predetermined motion time system
Predetermined motion time system
A predetermined motion time system is frequently used to set labor rates in industry by quantifying the amount of time required to perform specific tasks. The first such system is known as Methods-time measurement, released in 1948 and today existing in several variations, commonly known as...

 that is used primarily in industrial settings to analyse the methods used to perform any manual operation or task and, as a byproduct of that analysis, set the standard time
Standard time (manufacturing)
In industrial engineering, the standard time is the time required by an average skilled operator, working ata normal pace, to perform a specified task using a prescribed method...

 in which a worker should complete that task.

History

The basic MTM data was developed by HB Maynard, JL Schwab and GJ Stegemerten of the Methods Engineering Council during a consultancy assignment at the Westinghouse Brake and Signal Corporation, USA in the 1940s. This data and the application rules for the MTM system were refined, extended, defined, industrially tested and documented as a result of further work in later years.

In 1948, Maynard, Stegemerten and Schwab published the book “Methods-Time Measurement” giving full details of the development of the MTM system and its application rules. The use of MTM
MTM
-Computing and electronic games:* Mario's Time Machine, an educational game for the SNES* Midtown Madness, a series of racing computer games* Monster Truck Madness, another series of racing computer games-Science, technology, medicine and engineering:...

 spread, firstly in the USA and then to other industrialised countries. In 1951 the USA / Canada MTM Association for Standards and Research was formed by MTM Users. The system originators then assigned the MTM copyrights to the MTM Association.

Other national MTM Associations were founded and, at a meeting in Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

 in 1957, it was decided to form an International MTM Directorate
International MTM Directorate
The International MTM Directorate, originally constituted in Paris on June 25, 1957, is a Federation of National MTM Associations incorporated under the laws of Ohio on November 6, 1968...

 (IMD
IMD
- As a word :* IMD, Interchange Member Descriptors. * Imd, a family name* Imd, a giantess in Norse mythology, one of the nine Mothers of Heimdall- As an acronym :...

) to co-ordinate the work of National Associations. National MTM Association members of IMD now hold the MTM copyright
Copyright
Copyright is a legal concept, enacted by most governments, giving the creator of an original work exclusive rights to it, usually for a limited time...

s for their territorial areas.

Other MTM based systems have since been developed. MTM-2, a second generation system was developed under IMD auspices in 1965; MTM–3, a further simplification, was developed in 1970. The original MTM system is now commonly referred to as MTM-1. Other systems based on MTM have been developed for particular work areas by National Associations.

Methodology

Films were taken using constant speed cameras, running at 16 frames per second, of the work performed by qualified workers on the shop floor
Shop floor
--The Shop floor literally is the floor of a factory where people work on machines, or the space in a retail establishment where goods are sold to customers...

 at the Westinghouse Brake and Signal Corporation. Each sequence was rated during filming by three qualified Industrial Engineers
Industrial engineering
Industrial engineering is a branch of engineering dealing with the optimization of complex processes or systems. It is concerned with the development, improvement, implementation and evaluation of integrated systems of people, money, knowledge, information, equipment, energy, materials, analysis...

. These ratings had to agree within a close band, otherwise the sequence was not used.

The rating, or Levelling, system used was the Westinghouse or LMS system – so called after its originators Lowry, Maynard and Stegemerten. This system considers four factors independently:
  • Skill – Proficiency in following the given method
  • Effort – The will to work
  • Conditions – The general work surroundings
  • Consistency – of performance


Each factor is assigned an alpha rating, e.g. “B-“, “C+”, “A”, etc. which has a numeric value which is applied later. This reduces the possibility of “clock rating” and ensures that all factors are considered in the composite rating. Appendix 1 shows the model for Causes of Difference in Output on which the LMS system is based.

Layout
Layout
Layout may refer to:* Page layout** Comprehensive layout** In computer graphics, another name for a scene used to render 2D/3D graphics or animation* Layout , software that automatically calculates the positions of objects...

, distances, sizes of parts and tool
Tool
A tool is a device that can be used to produce an item or achieve a task, but that is not consumed in the process. Informally the word is also used to describe a procedure or process with a specific purpose. Tools that are used in particular fields or activities may have different designations such...

s and tolerances were accurately measured and recorded on the shop floor to complement the later analyses.

The films were then projected frame-by-frame and analysed and classified in to a predetermined format of Basic Motions. These Basic Motions were Reach, Grasp, Move, Position, Release, etc. A motion was taken to begin on the frame in which the hand first started performing the motion and was taken to end on the frame in which the motion was completed. This allowed a time for each recorded motion to be calculated in seconds, by means of a frame count, and then “levelled” to a common performance.

Plots of the levelled times for the various motions were drawn. Analysis determined the best definitions of limits of motions and their major, time-determining variables, and resulted in, more or less, the structure which the manual motions of MTM-1 have today. Later work, using Time Study, gave the table of Body Motions.

In 1949, Cornell University
Cornell University
Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...

 conducted an independent study of MTM for the American Society of Mechanical Engineers
American Society of Mechanical Engineers
The American Society of Mechanical Engineers is a professional body, specifically an engineering society, focused on mechanical engineering....

. It used camera speeds of 64fps. The MTM data was replicated within very close limits. Minor discrepancies revealed by the faster camera speeds have since been corrected in the MTM-1 data.

Detailed research conducted under the auspices of the USA / Canada MTM Association have resulted in minor changes to the data and the application rules and in a greater understanding of the nature of the motions. The last change was made to the detail of the Apply Pressure data in 1973.

MTM is complementary to other Industrial Engineering
Industrial engineering
Industrial engineering is a branch of engineering dealing with the optimization of complex processes or systems. It is concerned with the development, improvement, implementation and evaluation of integrated systems of people, money, knowledge, information, equipment, energy, materials, analysis...

 charting analytical techniques; it does not replace them. It should be used after broader techniques have established the Necessity and Purpose, Place, Sequence, Person and Means of the tasks to be evaluated.

Unit

The unit in which movements are measured for MTM is TMU (time measurement
Predetermined motion time system
A predetermined motion time system is frequently used to set labor rates in industry by quantifying the amount of time required to perform specific tasks. The first such system is known as Methods-time measurement, released in 1948 and today existing in several variations, commonly known as...

unit): 1 TMU = 36 milliseconds ; 1 hour = 100,000 TMU

1 TMU = 0.036 second

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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