Most often referred to as DFX, "Design for Excellence" is a tool used across disciplines in development and engineering to identify and formally address factors intimately related to a product's specific features when considering the entirety of the product's life cycle. As shown by the term's variant "Design for X," "excellence" in this case is not a value or standard but a variable to be defined case-by-case.
While DFX strategies may be applied at any stage of development, their focus on risk mitigation means that their success is increased exponentially when implemented early on, with specific advantages including shorter development timelines with faster go-to-market; reduced development costs; improved financial performance with comprehensive cost management; streamlined transitions when entering production; reduced supply chain risk; and higher device quality.
In the world of medical devices, efficacy, cost, and safety are the primary concerns in any development effort; at MIDI, DFX is deployed as a means of ensuring that they are prioritized both early in the design and throughout, defining "x" by a small list of factors for which all designs must be optimized, including:
- Manufacture
- Assembly
- Cost Optimization
- Testability
- Usability
- Supply Chain
- Service
- Reliability
Here, we'll take a look at these components of DFX, how they can be preemptively addressed, and why one should look to do so.
Design for Manufacture (DFM) and Design for Assembly (DFA)
- Aimed at ensuring that a product is producible in appropriate quantities at acceptable costs, DFM entails weighing functional requirements against production capabilities from early in the design process. When selecting materials, one should explore alternatives and consider options based on their methods of manufacture while keeping in mind the quantity projected to be produced per year. Under an AGILE development approach, by introducing these constraints during the POC (Proof of Concept) and prototyping phases, development is iteratively de-risked enhancing the results of production phases. Early implementation of DFA also occurs during these phases. It mitigates risks within some preliminary assembly approaches while considering device margin optimization as various assembly methods are evaluated for efficiency and resulting reliability.
Design for Cost Optimization
- While DFM and DFA both work to optimize manufacturing costs, DFC is distinguished as an independent variable to stress the importance of particular development techniques that, when performed preemptively, reduce BOM costs substantially. These include:
- Maintaining focus on high-cost components and assemblies.
- Engaging with vendors early in the development process to pinpoint optimum DFM/DFA methods easily converted to readily available and deployable industry practices.
- Carefully minding target production cost and price sensitivities within the target markets, often provided by competitive benchmarking analysis performed by marketing.
Design for Testability (DFT) and Design for Usability (DFU)
- When developing under an AGILE approach, design iterations are produced as soon and often as possible as a rapid method of de-risking. To comply with ISO-13485, design control documentation must be tightly controlled and closely tracked. System requirements are listed, distilled into design inputs, then used to generate verification and validation parameters for the device. These two components of DFX, then, are keyed to these parameters, with DFT pertaining to verification and DFU to validation. They go on to bear influence in the POC and prototyping stages and at the production level. Optimal results when performing DFT and DFU are contingent upon focusing early on balancing the functional requirements of your device with how easily it may be tested and validated.
Design for Service (DFS)
- The extended life cycle of a product is perhaps one of the most important things one should consider early in the design process, and this is probably especially true in the case of medical devices, where neglecting DFS can not only plant the seeds for hidden costs to both manufacturer and customer but present real risks to health and safety as well. Most development programs at MIDI optimize for DFS by integrating a robust service approach within the device in the form of IoMT (Internet of Medical Things) capabilities, which make remote diagnostics that allow for passive, minimally invasive attendance with a high level of risk mitigation.
Design for Reliability (DFR)
- Under the DevelopmentDNA™ approach, MIDI’s ISO-13485 Quality Management System (QMS) includes a SOP (Standard Operating Procedure) dubbed Product Realization, which dictates our AGILE development method's procedural steps, the INNOVATION ROADMAP™. Within, one may find DFR's introduction with the early implementation of a highly detailed approach to risk identification and tracking, Failure Mode and Effects Analysis or FMEA, which utilizes MIDI's cloud-based Design History File (DHF) in detailing all potentialities, including:
- DFMEA (Design Failure Mode and Effects Analysis): Focuses on functional design risks, enhancing device safety through the development of mitigation tactics.
- PFMEA (Process Failure Mode and Effects Analysis): Evaluates device design for any potential manufacturing and assembly risks during production or due to human error.
DFX is far more involved than the simple acronym would suggest, and executing its strategies effectively is no small task. For development teams, here are some practices that can help to ensure success:
- Build DFX activities into development plans and SOPs to ensure continual focus.
- Track DFX checklists for functional areas, including manufacturing, assembly, cost, testing (both verification and validation), procurement, service, and reliability.
- Institute a cross-functional team with representative experts in each "X" variable at the beginning of development.
- Test and review designs early and often, requiring DFX objectives within all project and technical review criteria.
- Develop an intentional plan for scaling with a keen understanding of your target production volume; executing this will be critical to effective design transfer into production.
Advanced DFX strategy is not just a means of ensuring safety or reducing costs but a tool that allows developers to gear design towards a specific product, project, and business objectives, something truly invaluable in times of change and instability.
Design for Supply Chain (DFSC) has been excluded from this overview; with global events as they are, the need to precisely and carefully address matters of supply during the development process is more significant than ever, and our strategy has grown to match. Keep an eye out for our next blog, which will cover how and why DFSC is attended to during a device's journey on the INNOVATION ROADMAP™.
To find more information on the other Xs in our definition of DFX, visit the MIDI Innovation Vault.
To hear more about Advanced DFX Strategy at MIDI, check out our new MIDI Innovation Vault™ podcast series: Advanced DFX Strategy & Supply Chain Paradigm Shift for Medical Device Development.