Completion time variance and the product rate variation problem

Just-in-time manufacturing necessitates finding short repeated sequences of products. The literature addressed this mixed model scheduling objective using the product rate variation (PRV), which maximises the deviation between the actual proportions and ideal proportions of jobs in the sequence. Researchers have reported application of PRV minimisation in manufacturing as well as in service industry. In this paper, we address this problem considering the completion times of the jobs in the sequence instead of the PRV, and show instances where maximising the sum of completion time variances (SCTVs) is an effective alternative to PRV for the mixed model sequencing problem. We propose algorithms using tabu search and genetic algorithms to solve the SCTV problem and show computational results.