Design Process

Design is the intentional arrangement of artifacts or ideas or processes in order to have a desired effect. We all practice design.

Engineering design is the application of design to problems that require training in one of the many fields of engineering. Although engineers can work in isolation on problems of limited scope, most engineering design work involves teams of people. Often those teams consist of people with training in different engineering disciplines and in related disciplines such as industrial design, manufacturing, and business.

Engineering design usually involves complex devices and processes and often requires a large investment in time and resources. Because of the cost and societal (environmental, economic, cultural) impact of engineering, the engineering design process has been studied and organized into several explicit procedures.

Definitions

Ulrich in his book Design and the Creation of Artifacts in Society gives this definition

.. design is part of a human problem-solving activity beginning with a perception of a gap in a user experience, leading to a plan for a new artifact, and resulting in the production of that artifact (Exhibit 1-9).3 This problem-solving process includes both design and production of the artifact. Design transforms a gap into a plan, which might, for instance, be represented with drawings, computer models, recipes, or parameter values. Production transforms a plan into an artifact.

Dym and Little, in their book, Engineering Design, 3rd edition:

Engineering design is a systematic, intelligent process in which designers generate, evaluate and specify designs for devices systems or procesess whose form(s) and function(s) achieve client's objectives and users' needs while satisfying a specified set of constraints

Both of the preceding definitions describe design as a noun: a process, an activity, an experience. Don Norman, an influential product designer, considers design to be a verb, and action.

Phase Gate or "Stage Gate®" Design Process

There are many ways to organize the design process. In ME 491, 492, 493 we will use the phase-gate (a.k.a. "Stage Gate®") design process that divides the design work into sequential phases or stages.

Note "Stage Gate®" is a registered trademark of Stage-Gate Inc.

Within each stage, iterations occur to refine ideas and plans to achieve the goal of that stage. The completion of a stage occurs when decisions are made to go forward to the next phase. While this sounds simple and tidy, it is difficult to put into practice because the requirements for the design are usually not fully known in advance. Furthermore, design work is complicated by the organizational difficulty of coordinating teams and working across knowledge domains of physics, math, statistics and economics used in the engineering design analysis.

In the course textbook, Mattson and Sorenson describe a six-stage engineering design process. We will be using that model in ME 491, 492 and 493

  1. Opportunity development
  2. Concept development (a.k.a. conceptual design or architecture development)
  3. Subsystem engineering
  4. System refinement
  5. Producibility refinement
  6. Post-release refinement

Recognize that this is a high level model meant to encompass a broad range of engineering design. This model, or variants of it, are often used in the design and manufacturing of physical products.

Each engineering project will have its own starting point, ending point and priorities. As such, some projects may involve only a subset of these activities, or some projects may prioritize the activities differently. For example, the design of a one-off piece of manufacturing equipment will likely end with the first fully-working version of the device is created. In that case, the producibility refinement and post-release refinement stages would fall under maintenance, and not be considered part of the product development process.

While it is important to understand and use a good process model in engineering activities, the best model for the job at hand will reflect the needs of that job. Therefore, you will likely need to adapt or interpret this model for different engineering projects.

Iterative Activity within Each Stage

Although the phases in the phase-gate model are sequential, activity within each stage is iterative. Refer to section 2.2 in the textbook by Mattson and Sorenson. Their design iteration cycle has four steps

  1. Focus: Identify the desired outcome
  2. Try: Attempt to achieve the outcome identified in the focus step
  3. Decide: Evaluate whether outcome has been achieved.
    • outcome not achieved: iterate again?
    • accept achieved outcome?
    • abandon outcomes and re-focus?
  4. Adopt: Accept outcome as part of the design
    • The design is changed (advanced) because adopted outcome is now part of the design

See also notes on design is iterative

Alternative models or mindsets

There are many ways of describing, organizing, and executing a design process. The diversity of methods reflects the many applications of design (architecture, engineering, fashion, business processes, etc.) and the challenge of describing a process that is creative, iterative, and evolving with the challenges and rapid development of technology. Hugh Dubberly, How do you design: A compendium of Models, documents over 100 design processes

Design Thinking

Design Thinking is a name applied to a disposition and set of tools used to create conceptual solutions and early prototypes. Design thinking is especially useful during the Opportunity Development and Conceptual Design phase of the stage gate design process used in Capstone.

Often, design thinking is represented as a sequence of steps. Here is the five-step version

  1. Empathize: First, focus entirely on what the intended user is currently experiencing. What problems do they face? What is their current experience? Be empathic in working with or observing the the user.
  2. Define: After observing and seeking to understand the user's current situation, what exactly is the problem to be solved? Note that this stage will likely need to be revisited after step 5 (Test).
  3. Ideate: Imaging solutions
  4. Prototype: Create artifacts or processes that address the problem
  5. Test: Let the user work with your prototypes to see if it really addresses the problem.

Assume that iteration is required.

Carissa Carter wrote a good, recent overview of design thinking (Oct 2016).

History of Design Thinking

Design thinking strategies have been popularized by Ideo and the Stanford d.school, but the term and techniques of design thinking predates both organizations. See for example:

  • Richard Buchannan, Wicked problems in design thinking,

  • Don Norman, Design of Everyday Things (19xx, p xx) as quoted by Jonny Schneider, Understanding Design Thinking, Lean and Agile, 2017, O'Reilly

Designers don’t search for a solution until they have determined the real problem, and even then, instead of solving that problem, they stop to consider a wide range of potential solutions. Only then will they converge upon their proposal. This process is called Design Thinking.

Rapid Learning Cycles

The Rapid Learning Cycles model focuses on identifying knowledge gaps and focusing work on learning in order to make decisions. Rapid learning cycles can be integrated within the stage-gate model. See, e.g. the book by Katherine Radeka, The Shortest Distance Between You and Your New Product: How Innovators Use Rapid Learning Cycles to Get Their Best Ideas to Market

Rapid Learning Cycles shares some ideas from Agile Design

Agile Design

Agile Design uses a set of principles that are particular effective for software development. The Wikipedia article is one place to start for more information.


Document updated 2017-10-24.