Reduction of changeover time in a small manufacturing make-to-order enterprise: A case study

Increasing competition has led more and more companies towards a careful waste identification and removal process, often by introducing lean oriented concepts and tools. However, especially for the application outside of the Japanese automotive sector, the implementation of lean manufacturing could face barriers that are difficult to overcome. This is particularly true in Small-and Medium-Sized Enterprises (SMEs), where, as a matter of fact, several of the management principles proposed in one of the most accepted characterizations of lean manufacturing are not respected (e.g. lack of a long term philosophy; scarce training of management and staff; insufficient organizational processes and standardized procedures). Scientific literature agrees that not all lean tools are sustainable and effective for companies of different sizes and sectors. In this study, we focus on the SMED (Single-Minute Exchange of Dies), a set of techniques that allows to reduce the changeover times, and thus it is particularly suitable for make-to-order companies. In these contexts, short changeover times bring several advantages, such as less inventory, greater production capacity or wider production mixes, and shorter lead times. Goal of this work is to report a case study of SMED implementation in a metalworking SME, which produces small mechanical parts for oleodynamic systems. We focused on the changeover times of multi-spindle cam lathes. To implement SMED, we followed these steps: after data collection and processing, we split activities between internal and external ones, maximizing the latter and dividing them between two different types of operators. This work led us to design a to-be changeover process and its standard procedures. The results we achieved present a significant reduction in changeover times, and cost-savings generated by the shift of activities on less-expensive operators. Also, the to-be process reduces inventory levels and it increases production mix or capacity.