AN APPLICATION OF LAGRANGIAN RELAXATION ALD SUBGRADIENT METHOD FOR A DYNAMIC UNCAPAITATED FACILITY COCATION PROBLEM

AN APPLICATION OF LAGRANGIAN RELAXATION ALD SUBGRADIENT METHOD FOR A DYNAMIC UNCAPAITATED FACILITY COCATION PROBLEM

The dynamic uncapacitated facility location model is formulated by a mixed integer programming. It has the objective of minimizing total discounted costs for meeting demands specified in different time periods at various demand centers. Costs include those for operation of facilities to demand centers and a fixed cost associated with the capital investment. The problem is decomposed into two simple Lagrangian relaxed subproblems which are coordinated by Lagrangian multipliers. We explored the effect of using the subgradient optimization procedure and a viable solution approach is proposed. Computational results are presented and further research directions are discussed.