MTM1 is a powerful technique but it takes a lot of time. Usually a one-minute cycle analysis is limited. To palliate, the MTM2 was developed in 1965 by the MTM International Committee with the participation of the Swedish MTM Association and the Swedish industry. It reduces the analysis time by 2. It is especially useful for doing a time analysis on multi-minute operations. Based on the work of the MTM1, it has a reliability level of 95%1 for cycle times of more than 5000 TMU.
The principle of MTM2 is based on the same functioning of the MTM1. The difference is that the MTM2 simplified the system by consolidating the actions. For this reason, it will be less precise than the MTM1 for small cycles.
The MTM2 comprises 2 categories of primary movements divided into 2 tables:
- The GET gestures : They combine reach (reach), grasp (grasp) and Release (Decher).
- PUT Movements : They combine Move and position.
The combined movements
When two movements are performed at the same time by the same member or part of the body.
Weight Correction for PUT and GET
- GW, weight correction for GET actions: Add 1 TMU/Kg per hand. If the object is taken with two hands, divide the weight by two.
- PW, weight correction for PUT actions: Add 1 TMU each 5kg.
Regrasp – Table R
The action of recapturing has the same definition as in the MTM1 with the assumption that the hand keeps control even between the two actions to grasp. If an action requires an action to re-enter, it must add 6 TMU.
Apply Pressure – AP Table
14 TMU are added when a hand or other member is used to apply an effort to an object. During the application of the effort, the object must not move on more than 6mm. Beyond that, we’ll take the AP table of the MTM1.
Eye Action – Table E
The actions of the eyes are the same as for the MTM1. We find both the movements of the eyes to look for an object and to look for a characteristic on an object. Whatever the action, a time of 7 TMU is added. If this action is part of another movement, no value is added.
Foot Action – Table F
A foot action has a value of 9 TMU. An action of the foot is considered for movements less than 30 cm and without movement of the trunk.
Step (walk) – Table S
A value of 18 TMU is added to each step (2 foot movements). Unlike a foot action, a step requires a movement of the trunk and is often larger than 30cm.
Bend and Rise – Table B
Whatever the movement, kneel, rise… a time of 61 TMU is allocated.
Crank – Table C
The definition of C is the same for the MTM1. Simply, a movement of less than 180 ° is considered a PUT and not a Crank. Beyond a half turn, we are well in a crank movement. In that case:
- If the resistance is low, it is allocated 15 TMU/turn.
- 1 TMU is added each 5kg.
In the same way as the MTM1, version 2 takes into account the fact that movements can be made at the same time and the rule of limiting principle applies. When two movements are performed at the same time by two different members:
- The total time of an easy or requiring exercise simultaneity (case 1 and 2) is the time of the greatest movement.
- The time taken for a difficult combination (case 3) is the addition of all times.
1 – J. P. Tanner (1991) – Manufacturing Engineering, an introduction to the basic functions
2 – Mr. Lehto, S. J. Landry (2013)-Introduction to human factors and ergonomics for engineers
S. Konz, S. Johnson (2000) – Work Design
S. Sakamoto (2010) – Beyond World class productivity