C Rajendran

This paper is the second of two papers that deal with the problem of scheduling in the permutation flowshop and flowline-based manufacturing cell with the consideration of different buffer-space requirements (or different in-process inventory levels) for jobs and the constraints on buffer-storage capacity between machines. We consider two sets of twin objectives of scheduling: one set consists of minimizing the idle-time of machines and waiting-time of jobs, and another set consists of minimizing idletime of machines and weighted waiting-time of jobs. We present a bicriterion heuristic, with a variant, to obtain a sequence that minimizes the twin objectives under consideration. The heuristic works in two phases. The first phase, i.e., ‘initial seed-sequence generation phase’, deals with the development of a good seed sequence with respect to twin objectives under consideration. The second phase is the ‘improvement phase’ in which the seed sequence, obtained from the first phase, is improved by using a new perturbation technique called ‘multiple random insertion technique’. An extensive computational experimentation has been carried out to compare the performance of the proposed heuristic and its variant with those of the existing heuristics for scheduling in the buffer-constrained and flowline-based manufacturing systems under study. The results of the experimentation reveal that the proposed heuristic and its variant emerge to be better than the existing heuristics. © 1997 Taylor and Francis Group, LLC.

We address the problem of scheduling in a Kanban-controlled flowshop with dual blocking mechanisms. The flowshop is also characterized by missing operations for part-types. We first present recursive equations for time-tabling of containers in a given sequence. We then present two heuristics for scheduling with the objectives of minimizing the sum of weighted waiting-time of containers and weighted flowtime of part-types. An extensive computational evaluation of the proposed heuristics is also presented. © 1997 Taylor & Francis Group, LLC.

In this paper, the problem of scheduling in a Kanban system with dual blocking mechanisms is considered. These blocking mechanisms are due to part-type and queue size. For such a type of static Kanban system, recursive equations are formulated for timetabling of containers. Subsequently, two heuristics are proposed with the twin objectives of minimizing the total weighted waitingtime of containers and total weighted flowtime of part-types. The results of computational evaluation are presented and discussed. © 1997 Elsevier Science B.V.

This paper is the first of two dealing with the problem of scheduling in a permutation flowshop and a flowline-based manufacturing cell. We consider the presence of different buffer-space requirements (or different in-process inventory levels) for jobs and constraints on buffer capacity between machines. We first identify that the existing formulation for scheduling in the buffer-constrained flowshop—which assumes the same buffer-space requirements for all jobs—is restrictive. Hence, we propose the generalized formulation of recursive equations for time-tabling of jobs in the buffer-constrained flowshop. The formulation also takes into account different buffer-space requirements for jobs. We extend the formulation to address the situation where transport times are separated from process times. Subsequently, we propose the formulation for time-tabling of jobs in the buffer-constrained manufacturing cell. © 1996 Taylor & Francis Group, LLC.