Sequencing for minimal tooling replacements via a variety of objective functions

This research presents a technique dedicated to obtaining production sequences resulting in minimal tooling replacements. Having sequences that result in fewer tooling replacements can result in savings owing to a smaller requirement for tooling media, and the reduced labour required to change the tooling. A variety of objective functions were used to assess the 'evenness' of tool wear, as it is assumed here that more evenness in tool wear would extend the life of the tooling. Because of the combinatorial complexity of sequencing problems, simulated annealing was used as a search engine to find sequences having desirable levels of the aforementioned objective function values. These obtained sequences were then simulated in a manufacturing environment to determine how many tooling replacements were required for the objective function of interest. Experimentation has demonstrated that the research presented here provides results generally superior to those of an earlier published effort in terms of the required tooling replacements (McMullen et al. 2002).