Part family formation: coding and classification systems

Abstract

Batch manufacturing produces a variety of different parts and accounts for 60–80% of all manufacturing activities (Chevalier, 1984). Moreover, at least 75% of all such parts are made in batches of less than 50 units (Groover, 1987). This large variety of parts and small batch sizes leads to part design and manufacturing inefficiencies such as inefficient use of design data, inaccuracies in planning and cost estimation, poor workflow, high tooling cost, high setup cost, large inventories and delivery problems. The remedy to these problems lay in sorting parts into families that have similar part design attributes and/or manufacturing attributes for a specific purpose. Design attributes include part shape (round or prismatic), size (length/diameter ratios), surface integrity (roughness, tolerance etc.), material type, raw material state (casting, bar stock etc.) etc. The part manufacturing attributes include operations (turning, milling etc.) and sequences, batch size, machine and cutting tools, processing times, production volumes etc.