Design, Engineering, and Problem Solving
Domain 3 - Design, Engineering, and Problem Solving (title provisional). This domain tests the engineering design process, criteria and constraints, modeling, prototyping, iteration, and trade-off reasoning. Questions often present an ill-structured problem and ask what a designer should do next.
Core rules and concepts
- The design process is iterative, not linear: define the problem, research, specify criteria and constraints, generate ideas, select, prototype, test, evaluate, communicate, and revise.
- Criteria are goals the solution must meet; constraints are limits such as budget, time, materials, safety, standards, and user needs.
- Divergent thinking widens options; convergent thinking selects among them. Brainstorming suspends judgment until ideas are generated.
- Models can be mathematical, physical, CAD, or simulation-based; each has assumptions and limits.
- Optimization weighs competing criteria; satisficing accepts a solution that meets minimum thresholds when perfect optimization is impractical.
- Failure analysis, such as root-cause tracing or failure modes and effects analysis, drives redesign.
Worked example
Design a phone stand for a school desk. Criteria: hold a phone at roughly 60°, fit in a locker, cost under $2, and have no sharp edges. Constraints: one class period, cardboard and hot glue only, and a 1 kg load test. A first prototype fails the load test because the hinge tears. The designer does not simply add glue; they identify the root cause - stress concentrated at a single fold - and revise with a triangular brace. This shows iteration driven by evidence, not guesswork.
Traps that cost marks
- Jumping to a solution before defining criteria and constraints.
- Confusing criteria with constraints.
- Testing one prototype and declaring success.
- Treating the process as strictly linear.
- Failing to document revisions and test data.