C Rajendran

The problem of scheduling in a flowshop, where setup, processing and removal times are separable, is considered with the objective of minimizing makespan. Heuristic algorithms are developed by the introduction of simplifying assumptions into the scheduling problem under study. An improvement method is incorporated in the heuristics to enhance the quality of their solutions. The proposed heuristics and an existing heuristic are evaluated by a large number of randomly generated problems. The results of an extensive computational investigation for various values of parameters are presented. © 1997 Taylor & Francis Ltd.

This article deals with the development of a heuristic for scheduling in a flowshop with the objective of minimizing the makespan and maximum tardiness of a job. The heuristic makes use of the simulated annealing technique. The proposed heuristic is relatively evaluated against the existing heuristic for scheduling to minimize the weighted sum of the makespan and maximum tardiness of a job. The results of the computational evaluation reveal that the proposed heuristic performs better than the existing one. © 1999, Taylor & Francis Group, LLC. All rights reserved.

Most of the heuristics for flowshop scheduling aim at minimizing makespan. However, scheduling with multiple objectives, such as that of minimizing makespan, total flowtime and machine idletime, is more effective in reducing the total scheduling cost. In this article, we first address the problem of scheduling to minimize makespan and total flowtime, and propose a new heuristic algorithm. A heuristic preference relation is developed as the basis for the heuristic so that only the potential job interchanges are checked for possible improvement with respect to these two objectives. The proposed as well as the existing heuristics are evaluated in a large number of randomly generated large-sized problems. The proposed heuristic algorithm is then extended to cover the problem of scheduling to minimize makespan, total flowtime and machine idletime. The results of the experimental investigation of the evaluation of this heuristic algorithm and the existing heuristic in meeting these objectives are also reported. It is found that both the proposed heuristics are more effective than the existing one for scheduling with multiple objectives. © 1995.