We study simulation optimization methods for the stochastic economic lot scheduling problem. In contrast to prior research, we focus on methods that treat this problem as a black box. Based on a large-scale numerical study, we compare approximate dynamic programming with a global search for parameters of simple control policies. We propose two value function approximation schemes based on linea...

⎯In this paper, we investigate the economic lot scheduling problem (ELSP) with fuzzy demands. We assume that the demand for each product i can be approximated using some triangular membership functions. In this study, we solve the fuzzy ELSP using two basic solution approaches, namely, the Independent Solution (IS) and the Common Cycle (CC) approach. For both approaches, we derive the optimal f...

We formulate the well-known economic lot scheduling problem (ELSP) with sequence dependent setup times and costs as a semi-Markov decision process. Using an affine approximation of the bias function, we obtain a semi-infinite linear program determining a lower bound for the minimum average total cost rate. The solution of this problem is directly used in a price-directed dynamic heuristic to de...

The economic lot scheduling problem has driven considerable amount of research. The problem is NP-hard and recent research is focused on finding heuristic solutions rather than searching for optimal solutions. This paper introduces a heuristic method using a tabu search algorithm to solve the economic lot scheduling problem. Diversification and intensification schemes are employed to improve th...

We deal with a multi-echelon inventory system in which one warehouse supplies an item to multiple retailers. Customer demand arrives at each retailer at a constant rate. The retailers replenish their inventories from the warehouse which in turn orders from an outside supplier. It is assumed that shortages are not allowed and lead times are negligible. These distribution/inventory systems are en...

although lot streaming scheduling is an active research field, lot streaming flexible flow lines problems have received far less attention than classical flow shops. this paper deals with scheduling jobs in lot streaming flexible flow line problems. the paper mathematically formulates the problem by a mixed integer linear programming model. this model solves small instances to optimality. moreo...

Economic lot scheduling problem has been an important topic in production planning and scheduling research for more than four decades. The problem is known to be NP-hard due to its combinatorial nature. In this paper, a meta-heuristics algorithm based on Simulated Annealing (SA) is proposed. Besides on explaining how to use SA, the effects of changing in production frequency on sequence and als...