6: Design & Planning – Part 3: Design for Excellence (DfX)

by Mike Freier

Design for Excellence (DfX) is a holistic approach to designing a hardware product that takes into account how the product is made at scale. In addition to understanding your manufacturing plan and target costs, there are six categories to consider: assembly, cost, manufacturing, test, service, and supply chain.

6: Design & Planning – Part 3: Design for Excellence (DfX)

Design for Assembly

Design for Assembly (DFA) is a design approach that aims to optimize the manufacturing process and minimize the complexity and cost of assembling a product. It involves identifying and focusing on the key factors that affect the ease and efficiency of assembly, such as the number of components, the fit and tolerances of the parts, and the order in which the parts are assembled.

One of the best ways for you to design for assembly is to setup a cross-functional team consisting of mechanical design and manufacturing engineers.  Both disciplines bring a perspective about best practices and can recommend several options for each assembly.  Collectively, your team can discuss the pros-cons of each option and arrive at the best DFA solution.  

Design for Cost  

Similar to DFA, a setting up a cross-functional team will help you optimize for cost. But, since Design for Cost (DFC) is such a broad topic, adding the following experts to your bench will help.

• Purchasing/procurement 
• Supply chain 
• Process engineering – eliminate unnecessary steps 
• Fixture/tooling engineers
• Test engineers 

Design for Manufacturing

Design for Manufacturing (DFM) is a design approach that optimizes the manufacturing process and minimizes the complexity and cost of producing a product. It involves identifying and focusing on the key factors that affect the ease and efficiency of manufacturing, such as the materials used, the number of components, the fit and tolerances of the parts, and the manufacturing processes and equipment required.

DFM is similar to DFA, but broader in scope to include the end-to-end manufacturing process. The image below shows how you can save a lot of money when it comes to volume manufacturing (production) by reducing the size, reducing the amount of assembly and test required and moving to mass produced plastic enclosures (where you can). The yellow prototype case on the left is bespoke, whereas the case on the right is a more cost-effective product version.

Design for Test 

Design for Test (DFT) is an important but often overlooked step in the early part of the development process. To improve DFT, it’s helpful to work with design, manufacturing, and quality engineers. While your design engineers understand what needs be tested, other parts of the organization can ask more specific questions like: 

• How many test points are built into the pc-board?  
• Can we automate parts of the test process? 
• Do we need to test sub-assemblies or just the final assembly?
• What is the pass/fail criteria for each item?

Design for Service (DFS) and Supply Chain (DFSC) 

Finally, you should think about how to design for service and supply chain.

Service

• Optimize the maintenance and repair process
• Minimize the time and cost required to keep a product operating at its best
• Identify key factors that affect the ease and efficiency of servicing a product
  • Access to parts
  • Use of standard components 
  • Availability of documentation and tools

Supply Chain 

• Optimize the flow of materials 
• Minimize the time and cost required to produce and deliver a product

Manufacturing Plan 

Choosing the right manufacturing strategy is critically important to save both time and money long term. Once your design is complete and you have a bill of materials (BOM), it’s time to start thinking about manufacturing strategy and plans. Here is a list of considerations: 

Successful product teams also need to think through the context and environment the CM operates in.

Target Costs for Volume Production 

Finally, understanding your target costs for volume production is the foundation of your profit margins.

• Manufacturing Cost
  • Parts (BOM)
  • Labor (estimate)
  • Manufacturing Overhead (markup) 
• Total Cost (markup) 
• LifeCycle Cost (markup) 

While lowering direct costs is advantageous, it’s equally important to keep in mind the risk associated working with low-cost suppliers that provide poor service and the additional cost of product returns and repairs.   

Essentially, DfX is about thinking ahead and understanding the tradeoffs inherent in manufacturing. 

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About the Author

Mike Freier is a Founder and Principal Consultant at the Product Management Consulting Group Inc.  He has 20+ years of experience with high-tech companies, including more than a decade in product management and product marketing.  He was a long-time board member and President of the Silicon Valley Product Management Association, served on the MIT-Stanford (VLAB) executive planning committee and spent several years mentoring start-up founders at the Cleantech Open.  Mike graduated from the University of Massachusetts at Amherst with a BSME degree.