This paper addresses the problem of minimizing the makespan on a two-stage parallel flow shops with proportional processing times. The problem of scheduling n independent jobs on m proportional parallel flow shops to minimize makespan is known to be NP-hard and hence too difficult to solve in polynomial time. A multiphase heuristic algorithm to minimize the makespan on two proportional parallel...

The global competition imposes minimizing the time-to-market and cost parameters, simultaneously increasing products quality and response to the customer demands. Information sharing, concurrent engineering and virtual enterprising prove to be stringent necessities in order to optimally achieve a better product design in an appropriate time. Automatically choosing the best products (accepting t...

In this paper, the idle speed control problem is addressed via maximal safe set computation. A hybrid model of the engine in idle mode is used. The solution is based on the transformation of the continuous dynamics from the time-domain to the crank-angle domain and on the linearization and discretization of these dynamics. A ‡exible and portable algorithm in the discrete-time domain is proposed...

In the past, we demonstrated how fuzzy concepts can easily be used in the Johnson algorithm for managing uncertain scheduling on two-machine flow shops. This paper extends these concepts to fuzzy flow shops with more than two machines. A new fuzzy heuristic flow-shop scheduling algorithm (the fuzzy Gupta algorithm) is then designed since optimal solutions seem unnecessary for uncertain environm...

We derive estimators of throughput sensitivity to changes in buffer capacity for continuous flow models of a transfer line comprising two machines separated by a buffer of finite capacity, where machines are subject to operation-dependent failures, i.e., a machine cannot fail when it is idle. Both repair times and failure times may be general, i.e., they need not be exponentially distributed. T...

This paper addresses the gradient estimation of transfer lines comprising two machines separated by a buffer of finite capacity. A continuous flow model is considered, where machines are subject to operation-dependent failures, i.e., a machine cannot fail when it is idle. Both repair times and failure times may be general, i.e., they need not be exponentially distributed. The system is hybrid i...

Flexible flow shops are becoming increasingly common in industry practice because of higher workloads imposed by jobs on one or more stages, thus requiring two or more units of the same machine type. We present a methodology for solving this important problem, namely group scheduling, within the context of cellular manufacturing systems in order to minimize the total completion time of all grou...