This paper reports a lot-sizing and scheduling problem, which minimizes inventory and backlog costs of multiple products on M parallel machines with sequence-dependent set-up times over T periods. Problem solutions are represented as product subsets (ordered or unordered) for each machine m at each period t. The optimal lot sizes are then determined applying a linear program. A genetic algorith...

We study lot streaming in shops in which the order the jobs are to be processed is immaterial. For a single job case, the properties of the optimal routing is determined. For the multi job case, two machine shops are analyzed. It is shown that lot streaming will improve makespan only if there is a job with large processing times. We show that there can be at most one such job and derive the opt...

This paper deals with the single machine multi-product lot scheduling problem in which defective items are produced in any production run of each product. We have adopted the common cycle scheduling policy and assumed that the setup times for production of each product can be non-zero. Further, we have assumed that defective items will be reworked and the inspection costs during the normal prod...

The Microbiological Criteria (MC) is a set of parameters used to determine whether a specific lot of food is acceptable or not. These parameters are the microbial test protocol and its sensitivity, the confidence level that an unacceptable lot will be detected, the number of samples to be taken and the number of positive samples that are allowed before rejecting the lot. Determining the microbi...

This paper presents a hybrid metaheuristic for solving the lot streaming problem in job shop production systems. In contrast with conventional tabu search implementations, where the disjunctive graph is adopted to represent the scheduling problem, our tabu search approach is based on permutation with repetition. Moreover, a specific procedure inspired by genetic algorithms is incorporated to se...