Cell formation is the first step in the design of cellular manufacturing systems. The main objective of this step is to cluster machines and parts into machine cells and part families respectively so that the minimum of intercellular part movements will be achieved. In this paper, we will focus on the configuration of machine cells considering production volumes and process sequences of parts. Also, we will study alternative process routings for part types and machine reliability considerations. A pure linear integer program will be developed to formulate this situation. The results of solving numerical examples show that the reliability consideration has significant impacts on the final block diagonal form of machine-part matrixes.