Predetermined motion time system

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A predetermined motion time system (PMTS) 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 three variations, commonly known as MTM-1, MTM-2, and MTM-3. Another popular PMTS is the Maynard Operation Sequence Technique, which was first released in 1972. That method also has several variations, with the most commonly used being BasicMOST, and others being MiniMOST, MaxiMOST, and AdminMOST. The variations of both systems differ from each other based on their level of focus. MTM-1 and MiniMOST are optimal for short processes with only small hand motions, while MTM-3 and MaxiMOST are more properly used for longer processes that are less repetitive. Unlike time studies, in which an analyst uses a stopwatch and subjectively rates the operator's effort to calculate a standard time, a PMTS requires that the analyst break apart the process into its component actions, assign time values to each action, and sum the times to calculate the total standard time.

Most predetermined motion time systems use time measurement units (TMU) instead of seconds for measuring time. One TMU is defined to be 0.00001 hours, or 0.036 seconds. These smaller units allow for more accurate calculations without the use of decimals. In the most in-depth PMT systems, motions observed will be on the level of individual TMUs, like toss (3 TMUs in MiniMOST) and simple pick-up (2 TMUs in MTM-1). More general systems simplify things by grouping individual elements, and thus have larger time values – for example, a bend and arise (61 TMUs in MTM-2) and one or two steps (30 TMUs in BasicMOST). Systems with even less detail work with TMU values in the hundreds, like climbing 10 rungs on a ladder (300 TMUs in MaxiMOST) or passing through a door (100 TMUs in MaxiMOST).

The choice of which variation of a certain PMTS to use is dependent on the need for accuracy in contrast to the need for quick analysis, as well as the length of the operation, the distances involved in the operation, and the repetitiveness of the operation. Longer operations often take place on a larger spatial scale, and tend to be less repetitive, so these issues are often treated as one. For longer, less repetitive operations, statistical analysis demonstrates that the accuracy of less detailed systems will generally approach the accuracy of more detailed systems. Thus, in order to reduce the time required for analysis, less detailed systems (like MTM-3 and MaxiMOST) are usually used when possible. Conversely, very short, repetitive processes are commonly analyzed with more exact methods like MTM-1 and MiniMOST because of the need for accuracy.

[edit] References

• Zandin, Kjell B (2003). MOST Work Measurement Systems. New York: Marcel Dekker. ISBN 0-8247-0953-5