Lagrangian relaxation technique is successfully applied to solve sequence dependent setup time flowshop problem to minimize the total weighted tardiness. The relaxed problem can be decomposed into each job-level subproblem that can be effectively solved by dynamic programming. Two types of the additional constraints for the violation of sequence dependent setup time constraints are imposed to t...

in paper (2004) chang studied an inventory model under a situation in which the supplier provides the purchaser with a permissible delay of payments if the purchaser orders a large quantity. tripathi (2011) also studied an inventory model with time dependent demand rate under which the supplier provides the purchaser with a permissible delay in payments. this paper is motivated by chang (2004) ...

background: breast cancer is the most frequently diagnosed cancer and the leading global cause of cancer death among women worldwide. radiotherapy plays a significant role in treatment of breast cancer and reduces locoregional recurrence and eventually improves survival. the treatment fields applied for breast cancer treatment include: tangential, axillary, supraclavicular and internal mammary ...

This paper presents a new mixed-integer goal programming (MIGP) model for a parallel machine scheduling problem with sequence-dependent setup times and release dates under the hypothesis of fuzzy processing time’s knowledge. Two objectives are considered in the model to minimize the total weighted flow time and the total weighted tardiness simultaneously. At the end, the effectiveness of the pr...

The flowshop scheduling problem with sequence dependent setup times is considered and shown to be NP-complete. A traveling salesman problem formulation is proposed for the case where jobs are processed continuously through the shop. These results are used to describe an approximate algorithm for the case where limited or infinite intermediate storage space is available to hold partially complet...

We consider scheduling a single server in a multi-class queue subject to setup times and setup costs. We examine the issue of whether or not reductions in the mean and variance of the setup time distributions can lead to degraded system performance. Provided that setups are reduced according to a stochastically smaller ordering, we show that if an optimal policy is used both for the original sy...