Design for Nonassembly: Current Status and Future Directions

Nonassembled products, which are produced from a raw material and post-processed to a final form without any assembly steps, form a large and potentially growing share of the manufacturing sector. However, the design for manufacturing literature has largely focused on assembled products and does not necessarily apply to nonassembled products. In this paper, we review the literature on design for nonassembly (DFNA) and the broader literature on design for manufacturing that has design guidelines and metrics applicable to nonassembled products, including both monolithic single-part products and nonassembly mechanisms. Our review focuses on guidelines that apply across multiple manufacturing processes. We identify guidelines and metrics that seek to reduce costs as well as provide differentiated products across a product family. We cluster the guidelines using latent semantic analysis and find that existing DFNA guidelines fall into four main categories pertaining to (1) manufacturing process, (2) material, (3) tolerance, and (4) geometry. We also identify existing product family metrics that can be modified for nonassembled products to measure some aspects of these categories. Finally, we discuss possible future research directions to more accurately characterize the relationships between design variables and manufacturing costs, including investigating factors related to the complexity of operations at particular process steps and across process steps.