The methods time measurement - universal analyzing system (MTM-UAS) is a methodology to clearly measure the processing times of some determined processes made by the operators, both manually and with the aid of some tools. The MTM methodology has been introduced in the '90s, and the last version is one of the most flexible and fast-to apply techniques, suitable in cases where relatively simple and short actions of the operator are involved. It is based on the classification of the possible operations done by the operator in 7 sections, that are translated in tables with different attributes from each other that returns values of processing TMUs depending on the situation.
MTM-UAS is a widely used method in the industry, especially when speaking about lot production. It is fast to use and quite flexible at the same time but it can have some limitations:
the focus is on basic operations and not on basic motions like some other versions of the MTM: this lead to a less accuracy in the evaluation, an important issue in situations where complex and high-effort actions are required;
subactivities are not taken into account, since the single activity has to be univocally assaigned to a specific section, and the time value is founded basing on the weight of the part handled, the accuracy needed in the movement and its difficulty;
due to this, it could be necessary to put attenction in the definition of the activities, to avoid the underestimation of the time due to a choice of a very large aggregate activities not providing the due details for the analysis.