Engineering in society

In Engineering, a problem is solved through an iterative process with four phases: Explore, Develop, Generate, and Evaluate and refine. The phases are not a straight line. Evaluate and refine acts as the decision point: after any phase you judge whether your evidence is good enough to move on, or whether you need to return to an earlier phase with better information.

In Unit 1 the context is a structural problem, such as a footbridge, shelter, tower, frame or support that must carry loads safely.

• Explore: describe the problem and its characteristics; break it into elements and components; research similar problems and existing solutions (best engineering practice); test or calculate the fundamentals, such as loads and spans; and set success criteria from needs and constraints.
• Develop: combine research and test results into ideas; symbolise ideas with sketches, drawings, models, tables and schemas; annotate and explain them; evaluate ideas against the criteria; calculate limits; test materials and processes; and propose a preferred solution.
• Generate: produce drawings to basic standards (by hand or CAD); calculate predicted prototype and real-world performance and present it in tables or spreadsheets; and make a prototype by hand, machine, 3D printing or laser cutting.
• Evaluate and refine: test the prototype (destructive, non-destructive, substitution or simulation testing); resolve uncertainties; reanalyse results; judge the solution against the criteria; and make justified recommendations.

Success criteria should be measurable where possible. 'Strong' is vague; 'supports a 5 kg load at midspan without visible permanent deformation' can be tested. A prototype is valuable because it gives data about whether the real-world solution is feasible, not because it looks finished.