It is well-known that for many project scheduling problems the space AS of active schedules contains at least one optimal solution for each feasible instance, so restricting heuristic construction methods to AS will improve algorithmic efficiency without foresaking the chance to eventually find an optimal schedule. Yet, for some problems such results are not directly applicable. We address one ...

The overlapping of activities is a common practice to accelerate the execution of engineering projects. This technique consists in executing in parallel two activities, normally executed in a sequential way, by allowing the downstream activity to start before the end of the upstream activity based on preliminary information. In this paper, we propose a constructive heuristic for the Resource-Co...

For most computationally intractable problems there exists no heuristic that is equally effective on all instances. Rather, any given heuristic may do well on some instances but will do worse on others. Indeed, even the 'best' heuristics will be dominated by others on at least some subclasses of instances. It thus seems worthwhile to identify for each instance anew a heuristic that is appropria...

Many meta-heuristic approaches have been suggested for or applied to the Resource Constrained Project Scheduling Problem (RCPSP). The existence of a number of highly accessible standard benchmark sets has promoted a research focus on finding anything that improves average solution quality, without investigating what effect is responsible for the improvement, or what is responsible for holding u...

This paper presents a Particle SwarmOptimization (PSO) algorithm for solving Resource-Constrained Project Scheduling Problems (RCPSP). The PSO model is a new population based optimization strategy introduced by Kennedy and Eberhart in 1995. The PSO is a cooperative and competitive algorithm who belongs to the class of the evolutionary algorithms. We here specialize the algorithm of PSO to the p...

This paper, we presents a new primary-secondary-criteria scheduling model for resourceconstrained project scheduling problem (RCPSP) with uncertain activity durations (UD) and cash flows (UC). The RCPSP-UD-UC approach producing a “robust” resource-feasible schedule immunized against uncertainties in the activity durations and which is on the sampling-based scenarios may be evaluated from a cost...

The aim of this paper is to show the usefulness of the Jackson’s pseudo-preemptive schedule (JPPS) for solving cumulative scheduling problems. JPPS was introduced for the m-processor scheduling problem Pm=ri; qi=Cmax. In the latter problem, a set I of n operations has to be scheduled without preemption on m identical processors in order to minimize the makespan. Each operation i has a release d...

In this thesis, we deal with modeling and solving various problems including vehicle routing and scheduling. We propose approximate methods that aim to solve problems quickly and e ciently. Five problems are addressed. The rst one is the Resource-Constrained Project Scheduling Problem (RCPSP) for which a multi-commodity ow approach is introduced. We also consider methods dealing with extensions...