Fuzzy Analytical Hierarchy Process Based Complexity Index for Investment Casting

The investment casting process is widely acknowledged as a manufacturing process for producing industrial castings with precise tolerances, excellent surface finish, and intricate designs across various sectors. However, the complexity of these castings has been predominantly described qualitatively, and a quantitative measurement of complexity has not been extensively studied. This research focuses on identifying specific characteristics that contribute to the complexity of manufacturing investment castings and developing a quantitative measurement of complexity. An in-person industrial survey conducted in a significant investment casting cluster, which accounts for approximately 25% of India's investment casting foundries, identified 212 meta-attributes that correspond to 52 attributes, further delineating 19 elements and 3 factors: geometry, features, and manufacturability. The Fuzzy Analytical Hierarchy Process (FAHP) was employed to ascertain the relative weights of the factors, components, attributes, and meta-attributes utilized in calculating the complexity index. The established complexity index was evaluated through various industrial castings and shown its utility for designers in using the investment casting technique for the production of intricate castings. This research corresponds with the principles of Design for Manufacturing (DFM) and Design for Investment Casting (DFIC) by offering a quantitative assessment of complexity in the investment casting process.