Ultimately, product design is often a balance between functionality, aesthetics, quality, and cost. Cost-effective design decisions are central to DFMA, as even the most innovative product won't succeed in the market if its manufacturing cost makes it uncompetitive or unprofitable. Every design choice has cost implications, from the material selected to the tolerances specified and the assembly method employed.

1. Material Selection:
2. Impact: Materials are a primary cost driver. Choosing less expensive materials can reduce costs, but designers must ensure they still meet performance requirements (strength, durability, appearance).
3. Considerations: Explore alternative materials with similar properties but lower cost. Optimize material usage to minimize waste (e.g., nesting patterns for sheet metal). Use recycled content where appropriate, as it can sometimes be cheaper than virgin material.
4. Part Count Reduction:
5. Impact: As discussed in DFA, fewer parts mean lower costs across the board.
6. Considerations: Integrate multiple features into a single part. Use standard components instead of custom ones. Eliminate unnecessary parts.
7. Process Selection:
8. Impact: Different manufacturing processes have vastly different costs per part, especially depending on production volume.
9. Considerations:
   • Volume: For low volumes, 3D printing or CNC machining might be cost-effective. For high volumes, injection molding (plastics), die casting (metals), or stamping (sheet metal) are often more economical despite high initial tooling costs.
   • Complexity: Some processes are better suited for complex geometries (e.g., 3D printing, CNC machining), while others are better for simpler shapes in high volume.
   • Secondary Operations: Design to minimize secondary operations (e.g., deburring, painting, polishing, drilling). If a feature can be formed during the primary manufacturing process (e.g., a hole molded in plastic), it's generally cheaper than drilling it later.
10. Tolerances and Surface Finishes:
11. Impact: Tighter tolerances and smoother surface finishes require more precise machinery, slower production rates, and more careful quality control, all of which increase cost.
12. Considerations: Specify the loosest possible tolerances and the roughest acceptable surface finish that still meets functional and aesthetic requirements. Don't over-specify. For example, if a part doesn't interact with another moving part, a rougher finish might be perfectly acceptable.
13. Assembly Efficiency:
14. Impact: Labor is a significant cost in assembly.
15. Considerations: Implement DFA principles: use snap-fits, reduce fasteners, make parts easy to handle and orient, and design for modular assembly. Design for automation if volume justifies the capital investment.
16. Tooling and Fixturing Costs:
17. Impact: The molds (for injection molding or die casting) and fixtures (for holding parts during machining or assembly) can be very expensive.
18. Considerations: Design parts that simplify tooling requirements (e.g., fewer complex undercuts in molds). Design for general-purpose fixtures rather than highly customized ones if possible. Consider the lifespan of the tooling in relation to the expected production volume.
19. Testing and Quality Control:
20. Impact: The resources and time dedicated to testing and quality checks add to the product cost.
21. Considerations: Design for testability, making it easy to check critical functions without extensive disassembly. Design quality into the product from the start (Poka-Yoke) to reduce the need for extensive end-of-line testing and rework.