In this paper, we treat an optimal control problem of a stochastic two-machine flowshop with machines subject to random breakdown and repair. While the problem is difficult to solve, it can be approximated by a deterministic problem when the rates of machine failure and repair become large....

We have developed a non-linear multi-objective model for optimal design of railway timetables. The objectives of the model are to maximize schedule reliability and minimize energy consumption, rolling stock and crew deployment. Metrics have been derived for each of these objectives. AHP is used...

The Shift Design Problem is an important optimization problem which arises when scheduling personnel in industries that require continuous operation. Based on the forecast, required staffing levels for a set of time periods, a set of shift types that best covers the demand must be determined. A...

We establish the computational complexity of the problem of minimizing makespan in a flowshop, where each jobs requires a pallet the entire time, from the start of its first operation until the completion of the last operation. We prove that the problem is NP-hard in the strong sense for m =2...

Combinatorial optimization problems are usually NP-hard and the solution space of them is very large. Therefore the set of feasible solutions cannot be evaluated one by one. Artificial Bee Colony (ABC), Particle Swarm Optimization (PSO) and Genetic Algorithms (GA) are metaheuristic techniques...

Supply chain scheduling is an integrated approach to the production planning and inventory control of systems. The purpose of this paper is to formulate the generalized supply chain scheduling issue in which the objective is to minimize sum of the costs incurred within all of the echelons of...

This paper calls for a change in paradigm in lot sizing and scheduling. Traditionally, a discrete time scale is chosen to model lot sizing and scheduling. As an alternative, the so-called block planning concept is proposed which is based on a continuous representation of time. A mixed-integer...

The paper is concerned with the problem of optimal production planning in deterministic pull flow lines with multiple products. The objective is to specify the production policy that minimizes the total inventory and backlog costs overtime. Assuming constant product demands and non-decreasing...

The multi-commodity network flow problem (MCNF) consists in routing a set of commodities through a capacitated network at minimum cost and is relevant for routing containers in liner shipping networks. As commodity transit times are often a critical factor, the literature has introduced hard...

We consider a production planning problem in an N-machine flowshop subject to breakdown and repair of machines and to non-negativity constraints on work-in process. The machine capacities and demand processes are assumed to be finite-state Markov chains. The problem is to choose the rates of...