MTM-based ergonomic workload analysis

Production engineers are urged to take ergonomic considerations into account when planning for production. However, the means to do so are often inadequate with respect to training as well as support. There is a lack of methods to predict, at a reasonable cost, biomechanical load on an operator performing a task not yet observable on a product and in a workplace not yet existing. The purpose of this study was to develop an ergonomic complement to a modern MTM system called SAM that gives the production engineer a first insight into the future ergonomic quality of a planned production. A method was developed that requests the engineer to supply two additional pieces of information to the analysis: the zone relative to the operator's body in which the movement takes place or ends, and the weight or force involved in the operation. As method of comparison for validation purposes was selected the operator self-evaluation method VIDAR. The method was tested at the Torslanda final assembly plant of Volvo Car Corporation and at the ITT Flygt plant for large submersible pumps at three different balances and compared with two different methods of assessing biomechanical load. The results show that the method identifies the events causing high biomechanical load on the operator so that they can be redesigned. The suggested method has proven to be a useful tool and is being introduced at Volvo Car Corporation. Under the concept of concurrent engineering the production engineer will have less time for experimenting with new production layouts. Given access to early design drawings of the product she or he must be able to decide on the future layout. There is a need for a tool giving the possibility to estimate simultaneously the consumption of time in the envisaged production, and the biomechanical load inherent in the planned tasks.