M.B. Aryanezhad - Department of Industrial Engineering, Iran University of Science and Technology,
E. Roghanian - Department of Industrial Engineering, Iran University of Science and Technology,

Bi-level programming, a tool for modeling decentralized decisions, consists of the objective(s) of the leader at its first level and that is of the follower at the second level. Three level programming results when second level is itself a bi-level programming. By extending this idea it is possible to define multi-level programs with any number of levels. Supply chain planning problems are concerned with synchronizing and optimizing multiple activities involved in the enterprise, from the start of the process, such as procurement of the raw materials, through a series of process operations, to the end, such as distribution of the final product to customers.Enterprise-wide supply chain planning problems naturally exhibit a multi-level decision network structure, where for example, one level may correspond to a local plant control/scheduling/planning problem and another level to a corresponding plant-wide planning/network problem. Such a multi-level decision network structure can be mathematically represented by using multi-level programming principles. This paper studies a bi-level linear multi-objective decision making model in with interval parameters and presents a solution method for solving it; this method uses the concepts of tolerance membership function and multi-objective multi-level optimization when all parameters are imprecise and interval .

Multi-level programming; Multi-objective decision-making; Multi-level multi-objective decision-making; Fuzzy decision-approach; Linear- programming with interval coefficients