Authors:
Fatma Hermès
1
;
Jacques Carlier
2
;
Aziz Moukrim
2
and
Khaled Ghédira
3
Affiliations:
1
Faculté des Sciences Mathématiques, Physiques et Naturelles de Tunis, Tunisia
;
2
Université de Technologie de Compiègne, France
;
3
Université de Tunis, Tunisia
Keyword(s):
Scheduling, Job Shop, Two Machines, No-idle Constraint, Makespan, Optimal Solution.
Related
Ontology
Subjects/Areas/Topics:
Artificial Intelligence
;
Formal Methods
;
Informatics in Control, Automation and Robotics
;
Intelligent Control Systems and Optimization
;
Optimization Algorithms
;
Planning and Scheduling
;
Simulation and Modeling
;
Symbolic Systems
Abstract:
This paper deals with two-machine job shop scheduling problems working under the no-idle constraint, that is, machines must work continuously without idle intervals. The makespan (Cmax) has to be minimized. First, we study the problem where each job consists of at most two operations and we show that it can be solved polynomially using Jackson’s rule (Jackson, 1956). Second, we study the problem where the number of operations per job can be greater than two and all operations are of unit time and we extend the results of (Hefetz and Adiri, 1982). Finally, we discuss the possibility of getting feasible solutions and then optimal solutions in the general case where the number of operations per job can be greater than two and all operations do not have the same processing time.