Design for Manufacturing Part III - Optimizing for Production

Design for Manufacturing Part III - Optimizing for Production

February 7, 2020 | Posted by Devin Carroll

Velentium offers a selection of services that represents the entire lifecycle of a device. Our engineers, developers, SMEs, manufacturing technicians, and production managers who support those services work together continuously: they aren’t segregated by project stage.

Having production engineers working side-by-side with concept designers gives us an unusual vantage point on both the design and manufacturing processes. In this series, for which we are joined by Production Manager Devin Carroll and Technical Manager Soumendu Bhattacharya, we aim to share some of our insights.

Welcome back! In this post, we’ll look at some of the manufacturing challenges the Production Team will consider. Think of the following as a highlight reel, not a comprehensive list. It should help illustrate the kinds of concerns that the design & development team may not prioritize.



The Production Team will evaluate off-the-shelf components listed in the design BOM against any known issues with item cost, availability, quality, or security. The Development Team’s first-pick components may not be suitable for mass production, for a variety of reasons. There may be less expensive alternatives. Some components may be frequently subject to backlogs or shipping delays when ordered at scale. A component may be readily available at the right price, but is known to have higher failure rates, requiring more extensive QA to weed out the bad ones during receiving inspections, thus driving up manufacturing time and costs.

Finally, a component with known security vulnerabilities may pose a security risk, or may necessitate additional manufacturing steps to mitigate those vulnerabilities. Note that security concerns will be flagged not by Production, but by Product Development Security while conducting a Design Vulnerability Assessment (VA). When the VA identifies mitigation solutions that involve manufacturing steps, the Production Team will be in a better position to evaluate the cost in time and resources to implement that solution and recommend for or against a component change.



In addition to the components themselves, the Production Team will evaluate the suppliers of proposed components. In controlled manufacturing, all suppliers are vetted against established criteria for inclusion on an Approved Supplier List (ASL). ASL vetting criteria include such things as:

  • Quality and maturity of the component production line
  • Responsiveness and effectiveness of customer service
  • Contract and confidentiality terms the supplier considers acceptable or unacceptable
  • Disclosure of details about the supplier’s facilities, operations, business culture, quality system, security practices, and outsourcing
  • Control of sub-suppliers and other business partners
  • Disaster recovery and incident response plans and readiness
  • Followup responses from supplier-provided references

When the Production Team reviews the design BOM, they will compare the proposed suppliers against their ASL and recommend changes based on discrepancies. Substitutions will need to be made for components provided by suppliers that have (A) failed to make the ASL, or (B) been removed from the ASL for any cause and not reinstated.

If the development or production schedule has sufficient lead time, rather than recommend design changes the Production Team may kick off ASL audits for any new or unapproved suppliers called out on the design BOM. Manufacturing cannot proceed unless all suppliers listed on the final production BOM have earned their place on the ASL.



Finally, the Production Team will look at the factory processes required by the proposed design, asking such questions as:

  • What are the sub-assemblies required? Can they be built concurrently with other steps of the main build or other sub-assemblies, each on its own dedicated production line?
  • What process validation and factory acceptance testing is required? At what stages of the build should each verification test take place? Has each necessary verification test been identified by the design team and captured in the Test Plan? Are factory-suitable test systems being designed to perform the testing, and is their impact on factory resources and takt time known?
  • Do any steps have the potential to introduce errors into the device, to damage or cause undue wear to equipment, or to harm operators? Do any steps introduce cybersecurity exposures, either of the device or of manufacturing infrastructure?

Ultimately, the Production Team is interested in ensuring that assembly processes will be efficient, repeatable, controllable, and assessable. Although they aren’t necessarily at odds with the Design Team’s interests, these aren’t the concerns foremost in the designers’ minds - especially for projects classified as R&D. Designers are working to create a device that can solve a particular problem or set of problems defined by user needs, use cases, and requirements. Although it may not feel this way on some projects, the R&D schedule affords designers plenty of time to physically assemble and pilot a few prototypes and early builds by comparison with the production schedule, which must conserve every possible second without sacrificing quality to achieve high-volume production cost-effectively.

Given those constraints, Production may request changes to the design that will make the commercial version more efficient to build, simpler to test with confidence, more impervious to process-induced variances and cybersecurity exposure, less likely to damage equipment or cause harm to manufacturing personnel, and less likely to produce a significant volume of units needing rework.



Now that we’ve reviewed some of the general concerns that Production Engineers bring to design evaluations, we’re better positioned to weigh the differences between our Scenarios A and B. Our next post will take a closer look at Scenario B, the more typical approach where Production is not involved in the design and development process until the Release / Transfer to Manufacturing Phase, and point to situations where a project is better served by this approach than by early optimization.



Get Started On Your Next Project