Everyone loves a surprise. That unexpected bonus, that bottle of wine from your colleagues for your birthday. But when it comes to outsourcing electronics manufacturing, it’s fair to say you want as few surprises as possible. That’s why you should always ‘Design for Excellence (DfX)
What is Design for X in manufacturing?
DfX (otherwise known as Design for Excellence) are the systems you use to 'bake' value and quality into products during their design phase.
DfX helps you optimise products for performance, reliability and efficiency as you plan and specify them, rather than having to improve and iterate in post-production.
Design for X: What does the X stand for?
The ‘X’ stands for excellence, but it also refers to the different elements involved in creating quality products which you can address systematically within the design process. These include DfMA (Design for Manufacturing and Assembly), DfT (Design for Testing), DfQ (Design for Quality), DfP (Design for Procurement), DfE (Design for Environment) and so on.
Why you need to Design for Excellence
Famously, 80% of costs are locked into a product at the design phase. In other words, once you’ve started manufacturing there’s not much you can do about any waste you identify later on. And this is a problem, as there’s a lot of waste about in manufacturing. The Lean institute say 95% of process activities associated with manufacturing ultimately add no value to the customer. Meanwhile, HCL Technologies say 70% of the engineering changes which delay production are due to brands trying to retrospectively correct issues with design to deal with assembly, cost & quality problems.
DfX optimises product design
DfX tackles the potential for procurement problems, over-specification and over-processing that can impact quality and make your products uncompetitive.
- Specified materials and components will always be available/replaceable
- Manufacturing waste is minimised
- Production errors are minimised
- Products always meet required standards
- Products can be tested easily and cost-effectively
And it does it from the start, as you plan and specify your products - and the way they should be made.
DfMA (Design for Manufacture and Assembly)
Design for Manufacturing and Assembly (DFMA) is the optimisation of a part, product, or component’s design to create it more cheaply and easily without compromising compliance or expected performance.
DfMA looks to:
- Minimise the number of components in a product: Combining or eliminating parts reduces assembly and ordering costs while simplifying automation.
- Design for ease of part-fabrication: Geometry of parts should be simplified and unnecessary features eliminated.
- Incorporate common parts and materials, including parts already in use in other similar products or assemblies. This helps minimise inventory levels and will result in lower cost and higher quality.
- Optimise for tolerances: Designers should model and evaluate interactions between component parts to avoid tolerance “stack-up” issues. Remember, too, that sub-assemblies made separately will need to fit into the "top level" final assembly.
- Choose modular designs to improve ability to update, service and maintain products. Modular assemblies can be improved and components swapped out with minimal effect on the rest of the product.
Design for Testing
A comprehensive test strategy should be developed concurrently with your product design. This approach will result in a cost-effective test process with the best possible test coverage.
DfT ensures you have designed your products so you can test them appropriately.
Successful design for testing requires designating important test points in your PCB design files, which your EMS will then use for a variety of tests.
The testing strategies you choose to deploy will require different design input levels and incur different levels of expenses. You need to optimise your design to ensure the right tests can be conducted to ensure the level of quality you require. These strategies may include:
- In-circuit test (ICT)
- Flying probe
- Soak test
- Stress screening
- Functional test
- Electrical safety testing
Design for Quality
A DfQ strategy identifies potential product and process failure risks as early as possible to ensure they are ‘designed out’ of the product.
DfQ ensures quality by:
- Identifying potential quality risks through Design Failure Mode and Effects Analysis (DFMEA), ranking potential severity of failures and prioritising areas for action.
- Specifying mistake-proof product design and assemblies: Products are designed so they can only be assembled one specific way, minimising potential non-conformities.
- Simplifying design: e.g. one piece is always better than two. Simplified designs reduce the risk of failure.
- Standardising parts where possible so compliance is easier to establish.
- Having a multi-functional team of experts to drive the process ensures the overall quality of the product is maintained within the design.
- Ensuring required documentation is completed within the design process helps prove regulatory compliance - helping you achieve ISO 13485, ISO 9001, CE marking and FDA certification as required.
- Ensuring design processes are stage-gated to continually validate deliverables against engineering/customer/regulatory requirements. Stage gating your design process is a requirement of the medical device development standard ISO 13485:2016.
- Ensuring required manufacturing processes are documented, validated, and engineers are appropriately trained to produce the product to the right standard.
Using a DfQ approach can also prevent you from getting locked into compliant but not necessarily cost-effective designs. If a design has proceeded to the prototype stage and been validated for regulatory compliance, you may be committed to manufacturing a product in a certain way for a lengthy period. It might not make sense to re-submit your design to regulators at that point - so your ROI and customer value could be severely impacted.
DfQ takes a holistic approach so that the best value and quality outcomes for customers are always achieved.
Design for cost and procurement
You can usefully factor in procurement and cost control expertise at the design stage, too. Done properly, this will help you focus on balancing cost and quality:
BOM (Bill-of-Material) cost is usually a significant portion of the total product cost, so exploring total cost of materials against quality requirements and considering possible alternatives could save you from expensive redesigns in the post-launch phase.
Ensure best value is always sought: For example, understanding that parts can be purchased at a lower price if you choose a particular colour or material will help the design team select the correct product and save cost.
Avoid using materials/components that are about to become obsolete: OEMs specify a particular chip in their design, which may be about to be phased out or become more difficult to source. Thinking about the availability of materials and components and drawing on supply chain expertise within the procurement team is vital.
Design for environment
Product designs can often have unintended environmental consequences, including:
- High level of waste through a lack of repairability.
- Damaging emissions during production.
- Use of unsustainable materials.
- Potential to pollute after disposal.
- An unoptimised supply chain with a large carbon footprint.
By bringing expert manufacturing teams into your design process you can ensure, from the outset, you are following best practice laid out in various environmental codes, including these standards and regulations:
- ROHS (Restriction of Hazardous Substances Directive),
- REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals)
- WEEE (Waste Electrical and Electronic Equipment recycling) standards
Who can deliver DfX?
A strong DfX team will coordinate efforts internally to ensure nothing is missed in the search for cost and quality control in manufacturing.
Bringing manufacturing expertise into your design process early on (as part of a DfX strategy) will ensure your product will be designed and then built in the most efficient and cost-effective way possible.
It will ensure you don’t waste time transferring unoptimised designs to Electronics Manufacturing Services (EMS) providers, but instead have all the required procurement, tooling, testing and logistics plans in place to shift to an optimised NPI without missing a beat.
DfX with a trusted EMS: helping you move seamlessly from design to NPI
How DFX beats traditional engineering approaches
Traditional engineering approaches often focus on vision and functional requirements first, while future product life-cycle and manufacturability concerns are addressed later on.
Design for Excellence, on the other hand, considers all these aspects as an integral part of the design process, so that the first iteration of your product is as efficient, cost-effective, easy to assemble and future-proof as it possibly can be.
If you work with a good EMS provider on a DfX strategy it should save you the time, effort and expense of adjusting designs when you meet the hard realities of production. Ultimately, it should prevent you from having to spend time and money re-engineering failing products in the future.