We study an iterative beam search algorithm for the permutation flowshop (makespan and flowtime minimization). This combines branching strategies inspired by recent branch-and-bounds a guidance strategy LR heuristic. It obtains competitive results on large instances compared to state-of-the-art algorithms, reports many new-best-so-far solutions VFR benchmark minimization) Taillard (flowtime wit...

The four-machine flowshop scheduling problem is investigated with the objective of minimizing total completion time. Job processing times are uncertain where only lower and upper bounds known. This common in some manufacturing environments. Some mathematical (dominance) relations established, an algorithm (with ten scenarios) proposed. proposed converts to a single machine for which optimal sol...

The issue of sequencing and scheduling has received considerable critical attention in many fields since the early 1950s. In this research, we studied an important production scheduling system, which generally called flexible (or hybrid) flowshop scheduling problem (FFSP or HFSP). We studied this production system with an important restriction called the no-wait. The objective was to optimize t...

The three-machine flowshop scheduling problem to minimize total completion time is studied where setup times are treated as separate from processing times. Setup and processing times of all jobs on all machines are unknown variables before the actual occurrence of these times. The lower and upper bounds for setup and processing times of each job on each machine is the only information that is a...

This paper studies a new generalization of the regular permutation flowshop scheduling problem (PFSP) referred to as the distributed permutation flowshop scheduling problem or DPFSP. Under this generalization, we assume that there are a total of identical factories or shops, each one with machines disposed in series. A set of n available jobs have to be distributed among the factories and then ...

Flowshop scheduling deals with determination of optimum sequence of jobs to be processed on some machines in a fixed order so as to satisfy certain scheduling criteria. The general problem of scheduling has been shown to be NP-complete. Exact algorithms, such as integer programming and branch-and-bound, guarantee optimality but do not yield the optimum solution in polynomial time even for probl...