m Bashiri - Department of Industrial engineering, University of Shahed, Tehran, Iran.
m Bagheri - Department of Industrial engineering, University of Shahed, Tehran, Iran.

Design of Cellular Manufacturing System (CMS) involves four major decisions: Cell formation (CF),Group layout (GL), Group scheduling (Gs) and Resource assignment (RA). These problems should beregarded, concurrently, in order to obtain an optimal solution in a CM environment. However; solvingcomplexity by simultaneous consideration of these problems will be increased. In order to over come this difficulty, in this paper a two stage heuristic procedure is proposed for CF and RA decision problems. The solution approach contains a heuristic multivariate clustering technique as the first stageto find the best machine-cluster center distances. Next in the second stage a new mathematical model based on extracted distances and also worker related issues including salary, hiring, firing and crosstraining is proposed. In order to verify and validate the performance of proposed approach amathematical model considering the inter-intra cell part trips and also operator related issues are developed and some numerical examples are solved using Lingo Software. Moreover, the necessity of simultaneous consideration of CF and RA is investigated. The analysis of results verifies the solution approach in both optimality and computational time aspects.

Cellular Manufacturing System,Clustering,Cell Formation,Operator Assignment,Linearization