A criticality analysis of kitting processes

A frequently adopted parts feeding policy in assembly lines is kitting, where all components needed to assemble one unit of the end item are placed inside a container to be individually delivered to the assembly line. Kitting supports the assembler's work but is penalized by relevant workforce cost for kits preparation, discouraging the use. However, recent literature highlights that kitting is a cost effective and competitive supply policy if logistic errors are considered. Nevertheless, usually kits are manually prepared. This exposes to manual error during the kit preparation phase (parts picking, counting, moving, delivering etc.), which determine product non conformities and errors correction costs. To reduce or remove the problem, error free kits are required. In this paper a dedicated innovative FMECA approach is proposed to improve kitting operations based on the main errors types occurring kit preparation. In particular, for each kit component the susceptibility to error commission based on its morphological and utilization characteristics (i.e. multiplicity, sequencing etc.) will be assessed. Then a risk priority number will be computed based on the error consequences and detectability at the assembly level (i.e. correction cost, potential harm to the user etc.). This allows to determine critical components based on their properties, and assess the components suitability to kitting. This may lead to kit redesign and improved training procedures for operators in order to reduce errors occurrence.