What is the design process?
Designing means planning something new that solves a problem for someone. The design process is the set of steps designers follow so they do not just guess.
- Investigate the problem and the user.
- Define it: write a design brief and a specification.
- Ideate: generate and develop ideas.
- Prototype: make models.
- Test and evaluate, then improve.
Different books use different names. Design thinking says empathise, define, ideate, prototype, test. The double diamond model says discover, define, develop, deliver: first you open up (explore widely), then you narrow down (choose), twice. All of them share one big idea: the process is a loop, not a straight line.
A linear process does each stage once, in order. An iterative process goes round again and again, improving each time. Agile development (used for apps and start-ups) makes small working versions quickly and improves them in short cycles.
Investigate and define: the brief and the specification
Investigation collects facts about the problem.
- Primary data is what you collect yourself: interviewing users, surveys, watching people use a product, measuring (anthropometric data: sizes of the human body).
- Secondary data comes from others: books, websites, existing products, standards.
- Analyse existing products: what works, what fails, what do they cost?
The design brief is a short statement of the problem and the goal, for example: "Design a leak-proof water bottle for students aged 11 to 16 that fits a school-bag side pocket."
The specification is a list of requirements that can be measured and checked later. A good checklist is ACCESS FM: Aesthetics, Cost, Customer, Environment, Size, Safety, Function, Materials. "It should be small" is weak. "Diameter at most 7 cm" is testable.
Constraints are limits you cannot change (budget, time, materials, laws). A feasibility study checks early whether an idea can really be made within those limits, and whether people will buy or use it.
Ideate and prototype
Generating ideas: brainstorm without judging, sketch many thumbnails, build a mood board of colours and images, borrow from nature (biomimicry, like Velcro copying burrs), or change an existing product step by step (for example with the SCAMPER questions: substitute, combine, adapt, modify, put to another use, eliminate, reverse).
Developing: pick the strongest idea using the specification (a scoring table helps), then refine it with annotated sketches, orthographic drawings or CAD (computer-aided design).
Prototyping: a prototype is a test model. A low-fidelity prototype is quick and rough (card, clay, paper app screens). A high-fidelity one looks and works almost like the real thing. Rapid prototyping uses tools like 3D printers and laser cutters to make models in hours. Prototypes are cheap ways to fail early, before costly production.
Test, evaluate, present and design responsibly
Testing checks the prototype against every line of the specification, ideally with real users. Record results honestly: pass or fail, with measurements.
Evaluating asks: does it meet the brief? What should change? Then you iterate. Asking users and experts for feedback is part of evaluation.
Presenting: show your journey (research, ideas, why you chose, tests and changes) in a portfolio, and present the final product with drawings, a model or a pitch. Designers also plan packaging and simple advertising.
Designing responsibly (eco-design): think about the whole life cycle: materials, making, transport, use and disposal. Use the 6 Rs: rethink, refuse, reduce, reuse, repair, recycle. Design for everyone (inclusive design), make it safe, and respect other people's ideas (patents, copyright).
Working in teams: big projects split roles (researcher, maker, tester), share a plan with deadlines, and review progress often.
Key formulas and definitions
- Design process: investigate → define → ideate → prototype → test/evaluate → (iterate)
- Brief = the problem and goal in a few sentences; specification = measurable checklist
- ACCESS FM: Aesthetics, Cost, Customer, Environment, Size, Safety, Function, Materials
- Volume of a cylinder: V = π r² h (1 cm³ = 1 mL)
- 6 Rs of sustainability: rethink, refuse, reduce, reuse, repair, recycle
Worked examples
1. Turn this weak spec point into a measurable one: "The bag should be light."
"The empty bag must weigh no more than 600 g." Now it can be tested on a scale.
2. Sort into primary or secondary data: (a) interviewing 10 classmates, (b) reading a website on bottle materials, (c) measuring the side pocket of 5 school bags.
(a) primary, (b) secondary, (c) primary.
3. A bottle body is a cylinder 7 cm across and 20 cm tall. Does it hold 750 mL?
r = 3.5 cm. V = π × 3.5² × 20 = 3.14 × 12.25 × 20 ≈ 770 cm³ = 770 mL. Yes, it passes (770 ≥ 750).
4. A prototype phone stand falls over when a big phone is placed on it. What should the designer do next?
Record the failure (which phone, what angle), go back to develop ideas (for example a wider base or lower angle), make a new prototype and test it again with the same phone. That is iteration.
Common mistakes
- Jumping straight to making without investigating the user. You may solve the wrong problem.
- Writing a vague specification ("nice", "small"). Every line should be checkable, ideally with a number.
- Falling in love with the first idea. Generate many before choosing.
- Thinking a failed test is a disaster. Failing early with a cheap prototype is the whole point; learn and iterate.