Economic comparison of manual and automation-assisted kitting systems

Parts kitting is a frequently adopted method to feed parts from a warehouse to an assembly line. While kitting allows minimization of space occupation and Work In Process holding cost at the workstations, also simplifying materials flow and supporting manual assembly, it is penalized by high workforce cost for manual kits preparation. For this reason automated kitting systems have been also proposed although their practical application is somewhat limited owing to the relevant capital investment and scarce performances of robotized kitting systems. Nevertheless, economic models allowing a quantitative comparison of manual and automated kitting systems are not yet available in the literature. In this paper a cost model to compare manual and automated parts retrieval in kitting systems is presented. It can be used as a decision making tool when planning and justifying kitting systems. The model includes capital investment, workforce, space occupation and quality costs. An application example is also included to demonstrate the model capabilities, showing that automation-assisted kitting systems can be competitive in comparison to manual kitting and that break-even conditions can be identified resorting to this model.