Predetermined Motion Time System

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 several variations, commonly known as MTM-1, MTM-2, MTM-UAS, MTM-MEK and MTM-B. Obsolete MTM standards include MTM-3 and MMMM (4M). The MTM-2 standard has also largely been phased out by the organization, but is still used in some commercial applications.

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. BasicMOST, MODAPTS and MTM-UAS are more suitable for processes that average around 1 to 5 minutes, while MTM-B and MaxiMOST are more properly used for longer processes that are less repetitive.

Yet another popular PMTS used today in the automotive, sewing and healthcare industries is the MODAPTS technique. This technique was introduced in 1966 by G. C. "Chris" Heyde who originally learned the MTM-1 and MTM-2 methods in the 1950s and sought a simpler technique to use and apply. Unlike the MTM and MOST standards, MODAPTS uses a MOD as its basic unit of measurement (1 MOD = 0.129 seconds). However, like Basic-MOST, MODAPTS uses a coding technique that consists of a letter and an integer number (all but 1 code), where the integer numbers each represent MODS that can be easily added to determine a coded task's time.

General Sewing Data is a PMTS for the sewn products and apparel industires and is based on MTM Core Data both proprietary data systems of GSD (Corporate) Ltd of Preston, UK. The Time standards for General Sewing Data are used in GSD Enterprise and GSD QUEST.

SewEasy is a more recent system used in Ready Made Garment (RMG) manufacturing, which is based on lean concept developed by Toyota. This system focuses on providing quick Standard Minute Values (SAM, SMV) for “sewing load balancing" in line with Value Stream Mapping (VSM) and "added value." SewEasy (Pvt.) Ltd has trained many juniors and seniors alike, to quickly establish standard garment sewing data by using this easy PMTS system.

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 (MTM and MOST) 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-B 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.

As technology advances and new solutions appear in the market, many myths and misconceptions also accompany the same. In a series of ‘Myth Busters’, Professor Prabir Jana from National Institute of Fashion Technology, New Delhi demystifies preconceptions of PMTS technologies; a link provided under references.