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 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...