Case for a Systematic Design Methodology

"The main task of engineers is to apply their scientific and engineering knowledge to the solution of technical problems, and then to optimize those solutions within the requirements and constraints set by material, technological, economic, legal, environmental, and human-related considerations [1]." This classic definition of the tasks of engineers sets up will a discussion of why systematic design is important for engineers. Engineers must solve problems given to them, which is in contrast to an inventor who gets to choose his problems and in contrast to a hobbyist who solves problems just for fun. The key consideration is the engineers are given jobs that they have no clue how to solve, and they are under very specific constraints.  A constraint on any engineer job is the time frame that a solution MUST be developed.

First, what is a systematic design method? A systematic design method requires the engineer to follow a specific set of steps during the design process. The steps can be flexible, but must be followed in the correct order.

First, a systematic design methodology should be used because randomly hoping for a bolt of inspiration to solve a problem depends heavily on the luck of the designer. In general relying on luck is not a good thing when given a specific time frame to solve a problem. Certainly, the more you think about a problem the more likely you are to come up with a solution because your brain has more time to make connections, but relying only on bolts of inspiration is a bad idea. In addition, many optimal solutions are not intuitive, so that it is doubtful if a non-systematic method would ever find them.

Second, a systematic design method helps generate a time frame or time line to help estimate key mile stones and completion times. Every client wants to know when they can expect a solution. A systematic method of design allows you to generate a specific timeline of when you expect certain aspects of the project to be finished. In addition, if things are not on schedule, it is simple to estimate how much the project is deviating from the original schedule and estimate how much additional  time will be needed.

Third, a systematic design method provides a common vocabulary or understanding of the current stage of design which promotes clarity. A common problem that I have found while working as an engineer is discussing design of an object on  a different level of abstraction of the design than what the other person is thinking. For example, I might be thinking big picture design, while they are discussing implementation details. If we both knew what stage of design we were working on then, the appropriate level of abstraction of the problem and solution would be more clear. In addition, a systematic design provides a framework so that everyone knows what to expect next so what all the engineers can be on the same page. Because modern design problems are far too complex for a single individual to solve by himself, engineers work in teams. Clear communication among the team is key solving any problem.   Non-engineers also benefit from a clear understanding what to expect in each design stage.

Fourth, a systematic design method allows the engineers to design for several X. Design for X includes design for manufacturing, design for sustainability, design for recyclability, design for ease of use, design for safety, and many others.  Each design for X burdens the engineer with another set of constraints that must be considered. To attempt to think about all the design for Xs at the same time would be impossible. However, by systematically considering each design for X, the product has the best chance of meeting each design for X.

Finally, a systematic design method produces documentation that shows clearly the reasoning of the engineer in a logical progression. An important part of design, is showing that the design has considered many possible alternative solutions and the final design was proven the best. Justifying your design is essential to prevent someone else from second-guessing of your engineering ability. In addition, by clarifying your assumptions and considerations during the design process, then when these assumptions change, the impact of the change can be easily found. Also, documentation aids in communication amongst engineers and non-engineers.

A systematic design method is often cited as killing creativity, but in reality a systematic design supports the engineers creativity by expanding his view and then focusing it on the real problems. The benefits of systematic design are well known, but often difficult to practice because we naturally want to jump to solution that we think might work. 

[1] Pahl G., Beitz W., Feldhusen J., & Grote K.H. (2007). Engineering design: A systematic approach (3rd ed.) Springer-Varlag London.

Product Planning (Stage 1 of product design)

Product design includes five main stages. A super simplified explanation of them are presented below. 

1. Product planning. The company strategically finds market needs, their company strengths, and determines several  potential products that they might develop. Using all this information they form a strategy of which  products that they will design to meet the market needs and company strengths. 
2. Product specification. After a product is generally defined for company planning purposes, the engineers and company managers need to define in some detail what they are attempting to design for a specific product. A long list of requirements that the product must meet is defined. 
3. Conceptual design. The engineers take the requirements and create 1-3 final ideas on how to meet these requirements.
4. Embodiment design. The engineer takes the 1-3 ideas and fleshes them out in much more detail. For a mechanical engineer this normally includes using CAD. As more information about the design is available, the ideas are evaluated and narrowed down to one design for the product. 
5. Detailed design. The product's manufacturing instruction, user manual, and other documentation is finalized. 

At school and generally on the internet, teachers focus on teaching , stage 4, embodiment design. However, all the stages are important. In my experience working as a paid engineer, small companies don't follow these 5 stages of design and the results are horrible. It is easy to have a good idea (which normally means you have a good idea for how to implement something, stage 4), and the company makes a valiant effort to get the idea to work. However, as soon as you include someone else in the design project, then things begin to fall apart because they don't see why your idea is so great and can point out several reasons why it is not great at all. Since you never clearly found out what people want (stage 1), you never defined what exactly you were trying to do (stage 2), and didn't consider alternative methods to solving the overall problem (stage 3), when someone else comes along and ask for justification for your design, you have nothing to show. For me, I was the new person, and I kept on asking "what are we actually trying to make (stage 2)? why are making it (stage 1)? why didn't you try something else (stage 3)?". Unfortunately, I never was given legitimate well documented answer to these questions. 

Recently, I've discovered another facet of product planning (stage 1). Once we have an idea of the product(s) we want to create, then we can create a strategy for how several iterations of the design will progress. In general when starting something new, it is best to keep things simple. The first iteration of a product that is released to  customer's should fulfill the basic requirements without bells and whistles. During product design enough things will go wrong so that creating a product which fulfills its core functionality well will be challenging enough.  

During product planning, the engineers can select core product functionality as the requirements for the first iteration, and then for later iterations incrementally increase the complexity of the product by adding features to it. Hopefully, the product specification for later iterations will also be influenced by customer feedback. 

The key idea I want to communicate is that you should plan out the iterations of your product as the very first step in product design. The first iteration should be as simple as possible. Later iterations should add features that add value. A common mistake is to make your first iteration far to complex with cool ideas. However it is also a mistake to totally forget your cool ideas. Cool ideas (features) can be planned for in later iterations of your product.