In this research, we study the multi-skill resource-constrained project scheduling problem, where there are generalized precedence relations between project activities. Workforces are able to perform one or several skills, and their efficiency improves by repeating their skills. For this problem, a mathematical formulation has been proposed that aims to optimize project completion time, reworki...

Resource Constrained Project Scheduling Problem is a very important problem in project management, manufacturing and resource optimization. We focus on a variant of RCPSP with time lags and variable activity durations. The solving approach is based on Precedence Constraint Posting that adds new precedence constraints to the original project graph so that all resource conflicts are solved and a ...

given a set  of  points in the plane and a constant ,-center problem is to find two closed disks which each covers the whole , the diameter of the bigger one is minimized, and the distance of the two centers is at least . constrained -center problem is the -center problem in which the centers are forced to lie on a given line . in this paper, we first introduce -center problem and its constrain...

In this paper we consider a constrained optimization problem where the objectives are fuzzy functions (fuzzy-valued functions). Fuzzy constrained Optimization (FO) problem plays an important role in many fields, including mathematics, engineering, statistics and so on. In the other side, in the real situations, it is important to know how may obtain its numerical solution of a given interesting...

Crossover operators that preserve common components can also preserve representation level constraints. Consequently, these constraints can be used to beneficially reduce the search space. For example, in flow shop scheduling problems with order-based objectives (e.g. tardiness costs and earliness costs), search space reductions have been implemented with precedence constraints. Experiments sho...

Constrained graphs are directed graphs describing the control flow of processes models. In such graphs, nodes represent activities involved in the process, and edges the precedence relationship among such activities. Typically, nodes and edges can specify some constraints, which control the interaction among the activities. Faced with the above features constrained graphs are widely used in the...

The resource-constrained project scheduling problem (RCPSP) consists of activities that must be scheduled subject to precedence and resource constraints such that the makespan is minimized. It has become a well-known standard problem in the context of project scheduling which has attracted numerous researchers who developed both exact and heuristic scheduling procedures. However, it is a rather...