MTM is a process that analyses all elementary motions movements and gestural useful for a manual operation realization.
It’s assign to anyone basic motion, identify a predetermined standard time which depend on the kind of gestural and conditions in which it’s done.
Those execution time, corresponding to a 100 running work, are gathering in a simply table which delete chronometry for all executive manuals work study of all factory’s subdivision.
MTM doesn’t have to be only considering like a time table. First of all, it’s a work simplification irreplaceable tool, using for methods improvement. The last few years, MTM using has spread in France, the systematic reach of the better operation method and the better fabrication method is becoming a constant necessity for all factories.
3 levels of MTM :
MTM 1 method allows you to study post and executive time coding for repetitive manual operation which cycle time doesn’t exceeding 1 minute.
MTM 2 method allows you to study post and executive time coding for repetitive manuals operation which cycle time is superior to 1 minute until 10 minutes,
MTM 3 method allows you to study posts and executive time coding for really short series or unitary manuals operation. (superior at 10 minutes)
MTS, UAS and SAM are method of the same level as MTM-2.
EQUINOXE is according by the French MTM association.
EQUINOXE implements the method of ergonomic quotation OCRA (OCcupational Risk Assessment).
This method calculates the risk of appearance of musculo-skeletal disorders on the level of the upper limbs. It takes into account :
the posture of the hand, the wrist, the elbow and the shoulder,
the effort made,
the gestures frequency (cycle time),
the periods of recovery frequency and duration.
It does not hold account of the environment of the operator:
environmental conditions such as temperature and hygrometry (without extreme conditions),
human relations at work,
It is based on the analysis of the technical actions carried out by the operator during his operating cycle. A technical action can be defined as an action which brings a biomechanical activity of the upper limbs.
The ergonomic risk incurred by an operator is characterized by an index which is the relationship between the number of technical actions carried out by the operator and the maximum number of technical actions that it should make taking into account the work realization conditions.
In EQUINOXE, the seizure of basic information is made on the level “work elements”:
number of Technical actions carried out in the element,
effort class according to the Borg scale,
percentage of the element time during which the hand carries out a pinching,
percentage of the element time during which the hand carries out a tightening,
percentage of the element time during which the wrist is requested,
percentage of the element time during which the elbow is requested,
percentage of the element time during which the shoulder is requested,
percentage of the element time during which particularly unfavorable conditions appear (pressure located on a part of the body, vibrations, irregular movements, jerked or with passing, need for a high degree of accuracy gesture, objects slipping, extreme temperatures).
The OCRA index is calculated on the level:
of an operation (case of individual stations),
balancing, for each working station.
Diagram of index OCRA calculated for each station of a line:
Map of risks
EQUINOXE draws a risk cartography by synthesizing the data by lines, by centers of expenses, process and for the entire factory.
Simulations of risk
for a line: average OCRA index workplace by workplace according to the products manufactured and to the production volume,
for an operator: average index OCRA according to the occupied workplace and to the manufactured quantities.