The partially-concurrent open shop scheduling problem is presented. The standard open shop scheduling problem is generalized by allowing some operations to be processed concurrently. This generalization is directly motivated from a real-life timetabling project of assigning technicians to airplanes in an airplane garage. A schedule for the partially-concurrent problem is represented by a digrap...

An interesting research area is to solve scheduling problems using network flow models and algorithms. Most of the existing papers in this research area deal with scheduling problems with parallel machines (identical and / or uniform machines). This paper considers the specialized case and develops network flow models and algorithms to solve open shop and flow and job shop problems.

Many problems in industry are a form of open-shop scheduling problem (OSSP). We describe a hybrid approach to this problem which combines a Genetic Algorithm (GA) with simple heuristic schedule building rules. Excellent performance is found on some benchmark OSS problems, including improvements on previous best-known results. We describe how our approach can be simply amended to deal with the m...

This is a summary of the journal article (Malapert et al. 2012) published by Journal on Computing entitled “An Optimal Constraint Programming Approach to the Open-Shop Problem”. The article presents an optimal constraint programming approach for the Open-Shop scheduling problem, which integrates recent constraint propagation and branching techniques with new upper bound heuristics. Randomized r...

We consider the open shop, job shop, and ow shop scheduling problems with integral processing times. We give polynomial-time algorithms to determine if an instance has a schedule of length at most 3, and show that deciding if there is a schedule of length at most 4 is N P-complete. The latter result implies that, unless P = N P, there does not exist a polynomial-time approximation algorithm for...

This paper presents a state of the art overview on Ants Systems. Initially the work proposes the fundamental concepts of Ants Theory and offers a description of the main algorithms (based on Ants Theory) and the respective fields of application. Among different fields of application, the paper focuses on industrial plants scheduling problems in open shop, flow shop and job shop systems. The las...

scheduling for job shop is very important in both fields of production management and combinatorial op-timization. however, it is quite difficult to achieve an optimal solution to this problem with traditional opti-mization approaches owing to the high computational complexity. the combination of several optimization criteria induces additional complexity and new problems. in this paper, we pro...

Scheduling problems in an open shop is more complicated than others since jobs do not follow a certain route in the system. This study uses computer simulation to compare the performance of different dispatching rules in an open shop. We find that the choice of the best dispatching rule is affected by the utilization factor, due-date factors, and the process time distribution at each station. I...