The Product Development Process – Step 4 – Design
The Product Development Process
Step 4 – Design
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 3rd):
- Conceptual Design – (the macro level) where fundamental and sweeping ideas are considered and evaluated;
- Principle Design or Characterization – (the micro level) where the details are composed;
- Oft times Proof of Principle phase(s) must be intertwined within to assure a complete and secure 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. 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 phases should be the best effort at perfection, with prototyping and testing as verification and acceptance.
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 schemes 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 white board or on paper. It’s a time for bringing good brains together, and a time for discussion. It is also a time for quiet contemplation where the group ideas are carefully thought through. Ideas are captured, evaluated, mutated, blended and reincarnated, 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 multiple sources.”
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.)
- 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) be created and tested in advance to assure that areas of technical stretch won’t delay launch?
- Are there substitute technologies to use if a new technology doesn’t make it?
- Examine impact on time and cost goals for each concept.
- Think like your customer and use that input as part of your decisions.
In many cases, technical innovation makes the task or project possible. These areas of technical stretch — or PoP’s (Proof of Principle) — must be evaluated carefully to see that they can be contained within time and/or cost constraints. Separating these areas of technical stretch into their own mini-projects (as a parallel path) keeps the main project rolling. We call these mini projects PoP’s. (See below for more discussion on PoP’s.)
The conceptual design phase is also a time for comparing competitive products against your list of requirements. Use the comparison to see how yours is similar, and to see how your requirements drive the new product to improve on what exists.
Conceptual Design (our Speaker Example)
For our speaker project, many speaker box and driver configuration ideas 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, and just a couple rose to the top. The front runners were those that best met the stated requirements.
The design finally chosen was certainly not the easiest or cheapest. It best meets the most important requirements, and it has a desirable personality from an artistic viewpoint.
Principle Design or Characterization
This is the stage of hard-core design engineering. It’s where the computer is handy — both for CAD and for design analysis. This is when fundamental design engineering takes center stage.
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 inputs or requirements.
- Coordination and Resolution of issues — especially those crossing between design teams.
- Incorporation of new knowledge and/or technology.
- Review of DFM, Design For Manufacturing feasibility, and other manufacturing questions.
- Review of progress with respect to timing.
The principle design stage should also include design optimization where areas of the design may iterate in getting to the elegant solution — one of the ways a design transforms from good to GREAT.
Design Engineering (our Speaker Example)
After choosing the “GO” concept, engineering for all the details including audio dynamics, exact sizes, driver placement, etc.. Without going into a lot of explanation, performance curves were optimized and final design details were completed. Speaker plans to build from are 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’s not a completely new concept, but something new as part of the product. It is these new, or inventive areas that we reference as PoP. We must Prove the Principle before in can go to market.
So, prior to inclusion with the main design, areas of technical stretch (innovation) get separate treatment. This may include prototypes ahead of time to determine if 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 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 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.
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 just in case the new process did not work. A lot of effort went into the design engineering of the lightweight part, then the process 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 along with many others. It also required the invention of a process to create the desired outcome.
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 illustrates how the proof came with not only a special design, but it also required the invention of a process.
Concluding Thoughts . . .
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