Engineering Design Process
This domain covers the design process as students are expected to practice it: framing a problem, specifying criteria and constraints, generating and selecting concepts, prototyping, testing against measurable targets, and iterating. The exam tests both design vocabulary and the reasoning that separates a defensible engineering decision from a preference.
The process, modeled
Most models-including ITEEA's engineering design process-share these stages: define the problem, research, specify criteria and constraints, brainstorm, select a solution, prototype, test and evaluate, iterate, and communicate results. The stages are iterative, not linear; testing frequently sends a team back to the problem statement.
Criteria, constraints, and the design brief
- Criteria are measurable goals the solution must meet ("support 25 kg with no more than 5 mm deflection").
- Constraints are limits: budget, time, materials, codes, ergonomics, safety, environmental rules.
- A design brief states the problem, client or user, criteria, constraints, deliverables, and timeline.
Divergent then convergent thinking
Brainstorming defers judgment, encourages unusual ideas, builds on others, and records everything. Selection is a separate, convergent step: screening matrices, weighted decision matrices, Pugh charts. Weighted scoring is defensible only when the weights are set before scoring.
Models and prototypes
- Conceptual, mathematical, virtual (CAD, FEA), and physical prototypes answer different questions.
- Rapid prototyping (3D printing, laser cutting) shortens iteration but has material and tolerance limits.
- Reverse engineering dissects an existing product to learn its design logic.
- Design notebooks document decisions, dates, and test data-evidence for assessment and for intellectual property.
Worked example
Three bracket materials are scored on strength (weight 0.5), cost (0.3), and machinability (0.2), each rated 1–5. Material A: 4, 2, 3 → 2.0 + 0.6 + 0.6 = 3.2. Material B: 3, 5, 4 → 1.5 + 1.5 + 0.8 = 3.8. Material C: 5, 1, 2 → 2.5 + 0.3 + 0.4 = 3.2. B wins under the stated weights even though C is strongest-that is the purpose of weighting.
Traps that cost marks
Treating the process as strictly linear; skipping research and jumping to a favorite solution; confusing criteria with constraints; testing without a measurable target; and describing iteration as evidence of failure.