This is a series of short articles as an overview and a simple guide, for how new products come to market. This article is Step 4, the Design Engineering for The Product Development Process.
Step 4 - Design Engineering
The Design
Phase
True design engineering is science and art; analysis and synthesis. It is compromise in the balance of conflicting constraints. It is drawing on, and improving upon previous knowledge for solutions - in new challenges, or new solutions to previous concerns.
At Synthesis, our goal is to find the Elegant Solution - not just any solution. It is our objective to find the best blend of compromise in all the conflicting constraints.
In development, the Design Phase has 2 main components (and often a third):
- Conceptual Design - (the macro level) where fundamental and sweeping ideas are considered, evaluated, and put together to achieve the product goals;
- Principle Design or Characterization - (the micro level) where the details are composed;
- Oft times Proof of Principle phase(s) are intertwined with the design engineering to assure a complete and secure final product deployment.
Discussion on each phase is in the sections below. Click the links for direct access.
Iteration in Design Engineering
Design phase is just one of the iterative steps in complete product development. Referring back to the map in the Process Overview (Step 1), the design phases often require iteration with Prototypes (step 5) and with Testing.
The process of Design to Prototype to Testing and back again is one of learning, usually with new inputs like customer acceptance, or manufacturing feasibility. It is part of understanding and perfecting the product so it will succeed in the market. How many iterations? That depends on the amount of learning and the final objectives.
Either way, the design engineering phases are the best effort at perfection, with prototyping and testing as verification and acceptance.
Conceptual Design
This is the big picture. Finding the best overall design always starts by considering various possibilities. A more complex problem deserves more concepts to consider. Start, with something like a brainstorming session, and measure all kinds of ideas. A reasonable list of requirements at this point is extremely valuable for assessment.
Side Note: There are many methods for collecting ideas, like Brainstorming or Sprints, and each has beneficial attributes. These alone do not constitute conceptual design, because there is no substitute for quiet, individual contemplation. Activities like Brainstorming can stimulate ideas and thinking in different directions, but they should be used to enhance and accelerate the design processes, not short-cut them.
The conceptual phase is a time for sketching on the whiteboard or on paper. It is a time for bringing good brains together, and a time for discussion. Also, it is a time for quiet contemplation where the group ideas are carefully thought through. Capture ideas, the evaluate, mutate, blend and reincarnate them, because design engineering is a process of sorting through possibilities.
It is my firm belief that the best ideas come from multiple good sources. By bouncing ideas back and forth, mutating them through the filter of various perspectives, the elegant solution rises to the surface.
"There is no smartest person . . . The best ideas come from synergy of multiple sources."
A "HARD" Note to Inventors
As an inventor you are the creative stimulus behind your idea. Obviously, that puts you in a key position, but realize that your ideas will stimulate creativity in others, too.
Many inventors suffer from NIH, "Not Invented Here" Syndrome. Unfortunately, that puts them on the defensive when others offer suggestions. This truly limits the potential of both the inventor and their product. Plus it makes the design engineering processes more difficult because of the physco constraints.
The good ideas of others can enhance and perfect your original concepts. Even when the new propositions are, in the end, not included, if they were honestly considered they will benefit the product by assuring all aspects are examined. New ideas or additions do not devalue the inventor; they enhance the product. Resistance to outside input degrades both.
A bad case of "NIH" is really a reflection of immaturity and lack of self confidence. Rise above it and success is far more likely.
* See also our web article feature for Inventors. *
Evaluating Concepts
There are always many ideas to sort through. Some stand out immediately. Other ideas are good, but conflict with each other. Here are some things to consider while evaluating and choosing which ideas are best:
- Analyze concepts for adherence to goals and requirements. (This is one reason you need the Engineering Specification of the previous step.)
- Determine areas of improvement over the competition.
- Find areas of technical stretch (if any) for each new concept.
- Does the concept require a new invention to make it work?
- Is there technology available to accomplish all the tasks?
- How can a Proof of Principle (PoP) assure that areas of technical stretch won't delay launch?
- Are there substitute technologies to use if a new technology does not make it?
- Examine impact on time and cost goals for each new idea.
- Think like your customer, or ask your potential customer(s), then use their input as part of your decisions.
In many cases, technical innovation makes the task or project possible. For areas of technical stretch, it is important to prove concepts in advance with a PoP (Proof of Principle) demonstration. A careful evaluation can help see if the innovation will fit within time and/or cost constraints. Separating these areas of technical stretch into their own mini-projects (as a parallel path) can keep the main project rolling. We call these design engineering mini projects PoP's. (See below for more discussion on PoP's.)
Design Engineering Competitive Analysis
The conceptual design phase is also a time for comparing competitive products against your list of requirements. Use the comparison to see how your ideas are similar, and to see how your requirements drive the new product to improve on what exists.
I have seen this process short-cut many times with a blind ambition that the new ideas are superior. This can lead to missing the most obvious things that potential customers already like, meaning it will be harder to gain acceptance in the market.
Conceptual Design (our Speaker Example)
For our speaker project, many speaker box and driver combinations were considered - some short and fat, some tall, some deep, and some shallow. It included drivers of all types and sizes. Then, as the designs were evaluated, just a couple rose to the top. The front runners were those that best met the requirements for dynamic range and consistent full sound.
The design finally chosen was certainly not the easiest or cheapest. Yet, it best meets the most important requirements, and it has a desirable personality from an artistic viewpoint. The design engineering of both the shape and the performance make it the best.
Principle Design or Characterization
This is the stage of hard-core design engineering. Now, the computer comes in very handy - both for CAD and for design analysis. This is when fundamental design engineering takes center stage, and the prior work of the Engineering Specification is the focus.
Typically this stage of the design includes work in all the areas of the project - perhaps by several individuals or teams depending on size and complexity. The routine generally includes individual work as well as design review meetings at appropriate intervals.
Design review meetings typically consist of:
- Design analysis reporting for adherence to the requirements (step 2).
- Coordination and Resolution of issues - especially those crossing between teams.
- Discussions about the incorporation of new knowledge and/or technology.
- Review of DFM, Design For Manufacturing feasibility, and other manufacturing questions.
- Reporting of progress with respect to timing.
The principle design stage should also include optimization where areas of the design may iterate in getting to the elegant solution - one of the ways a product transforms from good to GREAT.
A Note About Quality:
How do you define "Quality?" The best definition I have seen is:
"Quality is what the CUSTOMER says it is."
- L.P.Goates, Hewlett Packard
That means it is different for each customer. And, it requires research to know how a customer will view it. Truly, quality is quite different for a disposable product than for a durable one. Or for a software product compared to a physical product. It is also different if a warranty is provided. Know your customer.
If you build quality into the product and processes from the start, then it is free. If you wait, quality problems are very costly. For an example, look at the US auto industry design engineering - especially through the 1970's and 1980's.
Design Engineering (our Speaker Example)
After choosing the "GO" concept, engineering for all the details including audio dynamics, exact sizes, driver placement, volume calculations, angles, etc.. Without going into a lot of explanation, performance curves were optimized, and the final design engineering details were completed. Speaker plans ready to build are the output of this phase.
Proof of Principle - or - PoP
When conceptual design includes something technologically new, it creates a special condition. In many cases, it is not a completely new concept, but something new as part of the product. It is these new, or inventive areas that make a product exciting, but they are also areas that can bog down development. We reference these as PoP, because we must Prove the Principle before it can go to market.
We sometimes call these areas of innovation - "Technical Stretch" - that require Proof of the Principle.
So, prior to inclusion with the main design, areas of technical stretch get separate treatment. This may include prototypes ahead of time to determine if certain subsets of the technology will function to accomplish the goal.
For areas where current technology or a precedent does not exist, it must be invented. These areas must be identified early, then worked in parallel to see if they pan out. The main design engineering will usually have a back-up or "safe" plan to implement if the invention does not pan out. If, or when, the idea is proven or determined as safe for the prime design, it is incorporated.
This a development phase of product design engineering often requires invention or optimization using tools like Statistical Design of Experiments. Testing can be a big part of defining and achieving a technical stretch goal.
Proof of Principle Example 1:
A special lightweight part was needed for a support in a machine design. However, there was a conflict with the weight and strength requirements. To address the need a special version (lightweight) was conceived. The lightweight version was made with powdered metal sintered around a machined part. The powdered metal provides the shape and density desirable for weight, while the machined part provides the necessary strength and contact properties.
Though the concept seemed sound, at that time, a mixed material part as proposed had never been done. Could the process be reliable? Would it be safe?
To assure the component experiment does not delay product launch, a cast part (heavier, and more expensive) is a back-up if the new process did not work. A lot of effort went into the design engineering of the lightweight part, in parallel to the rest of the work. Once it proved, the lightweight design replaced the casting.
This is an example of using the PoP process to achieve desired goals without risking an entire product launch. Usually it satisfies the bosses that launch will be on time. Often, great things come in small ways.
Proof of Principle Example 2:
For one client, our job was simply to find the right combination of material, size, plating (if required) and geometry to accomplish a task. The function was extremely critical, so literally thousands of tests were conducted in a Design of Experiments fashion to find, and statistically verify a workable design. Tests included environmental chamber testing, pull testing, and many others. It also required the invention of a process to make the parts to fill the desired outcome.
We incorporate both design engineering and manufacturing process engineering. After many design and process attempts, the work finally concluded with a robust design combined with a proprietary process to satisfy the need and exceeded the given requirements.
This example illustrates how the proof for an inventive design came with not only with the invention, but it required the second invention of a process to implement it.
Concluding Thoughts About Design Engineering . . .
The design phase of product development includes several sub-steps that are usually iterative. First designs and first prototypes usually show opportunities for improvement, then additional design cycles hone the product. Especially for new technology, time for learning pays big dividends. Design engineering refinement in this way yields the best possible products.
Next Up: Step 5 - The Purpose of Prototypes