Method-Time Measurement (MTM) is defined as a system that “analyzes any manual operation or method into the basic motions required to perform it and assigns to each motion a predetermined time standard which is determined by the nature of the motion and the conditions under which the motion is made”, (Maynard, Stegementen, Schwab, 1948).
In other words MTM’s allow an individual's performance to be compared to a competitive industrial standard. Using MTM’s helps to give an accurate and quantitative judgment of a person's ability to perform a job; which is particularly important when assessing return to work capabilities and pre- and post-employment screenings. MTM scores also present a good way to track improvement over time, for example during a work conditioning or work hardening program.
Industrial time standards for performance of the Matheson Dexterity and Range of Motion Panel System (MPS) were established with the MTM Benchmark software (MTM-B) developed by the MTM Association for Standards and Research.
In order to set an MTM standard, a trained and qualified MTM practitioner studied digital video of well-trained workers disassembling and assembling the MPS. Video was analyzed to determine the MTM-based motions present in physical demands required of each protocol. These motions were then broken down into a system that looks at human performance in units equal to 100,000 segments per hour. These tiny units of time are referred to as “TMU” or Time Measurement Units. There are 27.8 TMU’s per second. Finally, the practitioner used the MTM Benchmark software to calculate the time standard. MTM engineering is a well established method of analyzing work tasks to determine how long a well trained industrial worker will require to complete a certain task at a rate that can be sustained for an eight hour work day.
MTM versus Normative Data
A normative-based system of test scoring is typically predicated on identifying a unique human population. That is, the system is based on comparing the performance of one group of humans against another group. Disadvantages of using normative-based systems over MTM systems include:
- Normative-based tests are usually based on a sample population and the sample may be biased by gender or race. MTM bases performance requirements on industry-based performance standards.
- Normative-based percentile scores do not necessarily predict whether or not someone meets an industry standard. For example, if a client performs at the 10th percentile on the Minnesota turning test this does not mean that he or she is too slow to do work that requires similar hand and finger dexterity demands. Perhaps 95% of the population is fast enough to meet industry standards for this kind of work. MTM bases performance requirements on industry standards which are reliable in determining suitability to perform specific short duration motions of work.