We propose a general-purpose heuristic approach combining metaheuristics and Mixed Integer Programming to find high quality solutions to the challenging singleand parallel-machine capacitated lotsizing and scheduling problem with sequence-dependent setup times and costs. Commercial solvers fail to solve even medium-sized instances of this NP-hard problem, therefore heuristics are required to fi...

A dynamic (multi-stage) stochastic programming model for the weekly cost-optimal generation of electric power in a hydro-thermal generation system under uncertain demand (or load) is developed. The model involves a large number of mixed-integer (stochastic) decision variables and constraints linking time periods and operating power units. A stochastic Lagrangian relaxation scheme is designed by...

We consider the problem of determining (for a short lifecycle) retail product initial and replenishment order quantities that minimize the cost of lost sales, back orders, and obsolete inventory. We model this problem as a two-stage stochastic dynamic program, propose a heuristic, establish conditions under which the heuristic finds an optimal solution, and report results of the application of ...

Fleet management addresses the problem of managing fleets of trailers, containers, boxcars, taxicabs, locomotives and business jets. In many applications, requests to be moved from one location to another arrive randomly over time. Since it may take days to move from one location to the next, it is often useful (even necessary) to reposition equipment before a customer demand is known. We use t...

in traditional portfolio selection model coefficients often are certain and deterministic, but in real world these coefficients are probabilistic. so decision maker cannot estimate them exactly. financial optimization is one of the most attractive areas in decision under uncertainty. in the portfolio selection problem the decision maker considers simultaneously conflicting objectives such as ra...

Mixed-model assembly line (MMAL) is a type of production line where a variety of product models similar to product characteristics are assembled. Line balancing and model sequencing problems are important for an efficient use of such lines. This paper presents integer programming formulation and a solution for a loading and assembly plan selection problem in a mixed-model assembly system. The p...

this article aims at designing the mathematical model for aras dam reservoir in time operation with missions of agriculture needs safeguarding, water electric energy production and torrent controls. reservoir system relations determinate and these relations at framework of are determined and stochastic dynamic programming are calculated executive results of this model are presentation of guides...

aggregate production planning (app) is one of the most important issues carried out in manufacturing environments which seeks efficient planning, scheduling and coordination of all production activities that optimizes the company's objectives. in this paper, we develop a mixed integer linear programming (milp) model for an integrated aggregate production planning system with closed loop su...