A Quick Look at DFMA

Is DFMA used more often to lower production costs for products already being made or when designing new products? Why? Wouldn’t it make sense to use it starting early in the design phase?

Jon Freckleton:  Once a company is tooled and in production, it is too late for DFM. Therefore, it is essential to have DFMA in mind from the first design concept. How a firm uses DFMA greatly depends on the forecast of production quantities. It is also important that firms have design and advanced manufacturing departments working together.

Baxter: That depends on the OEM. My guess is that DFMA is being used mostly on second- and third-generation products. By that time, OEMs have some real data on which to base DFMA decisions. DFMA at the early stage is always best for cost down initiatives, but there is a huge disparity in the DFMA skills of design and manufacturing professionals, so it makes sense that some companies are less fluent in DFMA for early designs.

Kehoe: I would agree that DFMA is used more for cost reduction after production as opposed to cost avoidance during the design phase. That is because product development has historically been linear. But using DFMA requires back and forth collaborations between design and manufacturing. That back-and-forth helps designers better understanding the manufacturing processes and helps manufacturing better understand the designs they are building.

Which has the biggest economic return, DFM (how to improve the manufacturing of parts and components) or DFA (how to improve the processes of putting together parts and components into assemblies and then completed products)?

Freckleton: They are not separate; they must be considered together and must include repair if that is a factor, and recycling, which is always a factor unless it is an expendable item such as a bomb. A non-repairable item can be ultrasonically welded or have a permanent snap fit, but not if it needs to come apart for maintenance or repair.

Baxter: This depends on a host of factors, but a good rule of thumb would be to Pareto lower cost ideas and first attack high-fliers with the lowest risk. Sometimes the two are intertwined, such as when redesigning a part to make its assembly easier (like adding a keyway) but increasing the part’s price. It also depends on how quality is affected at either the manufacturing or assembly levels.

Kehoe: Both. DFA takes a “big picture” approach and DFA software helps “visualize” those savings. DFA analysis is best done with product and manufacturing knowledge. Simply applying a DFA analysis to an assembled product is only beneficial if there is an intimate knowledge of the available design options from the design and manufacturing perspectives.

What key features are companies adding to DFMA software?

Baxter: There are some DFMA platforms that give real-time feedback about features that can be really handy, such as locations or relations of features, and hole sizes as compared to nominal drill sizes. These are very powerful. Once these platforms can analyze and compare DFMA features against production volumes and make process suggestions, DFMA software packages will make huge leaps.

Kehoe There are some DFMA packages that provide on-the-fly cost feedback from CAD models and how changes can affect cost.

Is DFM well-covered in undergraduate engineering curriculums? If not, how should it be taught—as one major course (and lab) for all engineering students, or as part of several required courses in a student’s chosen field of engineering? As an aside, are there enough people qualified to teach college-level DFMA to handle all the engineering undergrads?

Baxter: Luckily for me, I took a DFMA class with a lab at Rochester Institute of Technology, and I am glad they offered it. It taught me the principles of DFMA and in our final project each of us applied those principles to a real product and developed new designs and cost estimates. It taught me a lot.

But based on what I’ve garnered from designers I’ve met, college-level DFMA courses are not well-staffed. DFMA courses also require real-world interaction (for getting prices, for example) that most colleges cannot offer.

Freckleton: First off, a Ph.D. who has never worked in product development and production cannot teach it. Ideally it should be covered in many engineering courses and also covered in a course devoted to DFMA. It should also be an important part of any appropriate capstone senior design project. Hose senior projects should be industry sponsored and involve actual design problems and challenges. They should also be multi-department or multi-discipline projects where appropriate, as this is usually the case in the real world.

I cannot answer as to how well it is covered these days, but as a hiring manager at several tech companies, I never found a properly prepared B.S. grad.

Since Industry lacks enough people with this background, they are in demand. And since colleges look down on—and usually will not hire—anyone lacking a Ph.D., it is often taught by adjuncts who cannot present a demanding-enough course, and do not have daytime office hours and availability to students for project support.

Kehoe: No. Undergraduates do not have enough design or manufacturing knowledge to apply DFMA. I would support the influx of DFMA any time critical thinking of product development is part of a curriculum. Dedicated DFMA classes can be considered specialized since engineering undergrads would need to do significant research to understand design factors and manufacturing factors of cost.

That is a major challenge for a younger student. Mostly this can only be substituted with practical experience. The principles of DFMA are questioned throughout the curriculum and then re-enforced with research. Only then can this become a tool for use in practical application.

I cannot speak the state of education at this time, but I can attest to the fact that through six years of graduate work, the education department was not able to embed DFMA principles into programs of study. I took a dedicated class as a graduate student, but also had close to 20 years of experience. I was able to absorb the principals and apply them from my extensive knowledge of Manufacturing and Design.

What industry seems to be the best at using DFMA and enjoying significant benefits from it? Why is this industry doing so well?

Baxter: One thing I know is that every industry wants DFMA. I’d guess that automotive and electronics are the best at using DFMA based on their deep pockets, R&D commitments and predictable, high-volume forecasts. They also have lots of weight with their suppliers so they can easily get pricing and cost ideas from the supply chain to verify their DFMA concepts.

Why haven’t other branches of DFMA taken off, such as Design for Reliability, Design for Serviceability, Design for Environment, Design for Recyclability, Design for Disassembly and so on?

Freckleton: Idiots in management.

Kehoe There needs to be culture or paradigm shift in a company to where these approaches are infused into the design while it is being developed, not after the design has been completed.

Baxter: Usually cost is the first thing I hear regarding DFMA efforts. The costs in DFMA efforts are immediate and less theoretical. In other words, DFMA costs seem to be more tangible, so they get more consideration from decision makers.