Assembly work execution and materials kit functionality in parallel flow assembly systems

Abstract

This paper reports on materials kit functionality — usefulness of the materials kit in respect of operators’ handling of materials and cognition during assembly work. That is, how the materials kit facilitates assembly work as well as promotes learning. This analysis comprises video recordings of nine automobiles in total from the closed down Volvo Uddevalla plant; a plant with parallel flow, long cycle time assembly work, where the materials supply was designed to facilitate the assembly work. To evaluate the usefulness of a materials kit from an assembly point of view, its configuration was related to the observed assembly work, and the level of structural congruence was estimated in order to judge to what extent the materials kit actually supported the assembly work. Briefly summarised, by using an analysis method in the form of ‘signal component’ methodology, this analysis showed that the assembly work proved to be almost identical when there were no technical differences between the layouts. It was thus assumed that it is possible to design materials kits in accordance with the observed assembly work, even though the materials kits configuration in the case study was not fully optimised and the stipulated work patterns were not in agreement with the observed work patterns. The ideal situation is that the operator picks components from one materials container at a time; however, it turned out that the operators picked from nearly two materials containers simultaneously. Relevance to industry Parallel flow, long cycle time assembly systems call for knowledge about conformity in the execution of assembly work within a work group. This paper reports on a case study focusing on the possibility to design common materials kits and assembly instructions, which in turn influences e.g. materials supply and learning times.