an alternative for decreasing risk for knowledge workers is effective & optimized work break.major performance criteria in r&d; based organization is successful projects. selection of opproporiate members can be a most effect on the projects achievement. but as the selection of r&d; special members lead to decrease of risk, repeatative participation of this people in the same project lead to kn...

 In this research, a tri-objective mathematical model is proposed for the Transportation-Location-Routing problem. The model considers a three-echelon supply chain and aims to minimize total costs, maximize the minimum reliability of the traveled routes and establish a well-balanced set of routes. In order to solve the proposed model, four metaheuristic algorithms, including Multi-Objective Gre...

In industries machine maintenance is used in order to avoid untimely machine fails as well as to improve production effectiveness. This research regards a permutation flow shop scheduling problem with aging and learning effects considering maintenance process. In this study, it is assumed that each machine may be subject to at most one maintenance activity during the planning horizon. The objec...

This paper presents a bi-objective MIP model for the flexible flow shop scheduling  problem (FFSP) in which the total weighted tardiness and the energy consumption are minimized simultaneously. In addition to considering unrelated machines at each stage, the set-up times are supposed to be sequence- and machine-dependent, and it is assumed that jobs have different release tim...

Much attention has been paid to evolutionary multi-objective optimization approaches efficiently solve real-world engineering problems with multiple conflicting objectives. However, the loss of selection pressure and non-uniformity in distribution Pareto optimal solutions objective space can impede both dominance-based decomposition-based optimizers when solving many-objective problems. In this...