Developing & Reviewing the Chosen Design
From Initial Ideas to a Chosen Design
By this point in your non-examined assessment you will have generated a range of initial design ideas (NEA 2.1). The next three stages ask you to review those ideas, develop the strongest into a single chosen design, and then review that final choice before you start making. This is not a straight line through a checklist — the specification describes design as an iterative design process, meaning ideas are tested, evaluated and refined again and again as your project moves forward.
Reviewing Initial Ideas (NEA 2.2)
NEA stage 2.2 is worth 8 AO3 marks. You must analyse and evaluate how well each initial idea meets the design brief and the design specification. This means checking every idea against every relevant point in the specification, not simply deciding which idea you personally prefer. Ideas that meet the brief and specification are selected to take forward into development; ideas that only partly succeed are modified so they fit better, and ideas that cannot be made to work are dropped.
Reviewing initial ideas means: (1) analysing each idea against the specification, (2) deciding which ideas to take forward, and (3) modifying ideas that only partly meet the brief.
Developing the Chosen Design (NEA 2.3)
NEA stage 2.3 is the largest single stage in Design, worth 4 AO1 marks and 8 AO2 marks. You take the strongest idea, or ideas, forward from 2.2 and refine them into one chosen design. This includes carrying out further research if you need more information, and considering the design as a whole rather than looking at separate parts in isolation — a well-designed handle is no use if it does not fit the rest of the product. You should also incorporate feedback from any testing or modelling as you go, rather than saving it all for the final review.
A key skill here is modelling and simulation. You might test a mechanism with a card mock-up, check a fit using a 3D-printed part, or simulate a circuit before committing to it. Modelling lets you find problems while they are still cheap and quick to fix, rather than discovering them once the prototype is nearly finished.
NEA 2.3 requires calculations that determine material quantities and give technical detail clear enough that someone else could manufacture the product without asking you further questions.
For example, a polymer component in a chosen design measures 120 mm by 60 mm. Area of one component: $$120 \times 60 = 7200\text{ mm}^2$$ Converting to cm² by dividing by 100: $$7200 \div 100 = 72\text{ cm}^2$$ For a batch of 15 identical components: $$72 \times 15 = 1080\text{ cm}^2$$ of sheet polymer is needed, before allowing extra material for waste at the edges of the sheet.
Tolerances and Efficient Use of Material
Alongside material quantities, your technical detail should state a tolerance. No manufacturing process cuts a component to an exact size every single time, so a tolerance such as ±0.5 mm tells whoever makes the product how much variation is acceptable while the parts still fit and work together.
Calculations should also support efficient use of material. Marking out components close together on a sheet, or nesting shapes to leave minimal offcuts, reduces waste and cost. This links directly to the sustainability and cost factors you studied in the core content, and you need to apply that knowledge here, not just in Section A of the exam.
Calculation marks are earned through the correct formula, the correct steps shown as working, and the correct final answer. An unsupported final answer can lose method marks even when it happens to be right.
Reviewing the Chosen Design (NEA 2.5)
NEA stage 2.5 is worth 6 AO3 marks. Once you have a chosen design, you analyse the refinements you made and evaluate them with reference to feedback from others — your teacher, peers, or a client — not only your own opinion. You should also confirm that the materials, components and manufacturing techniques you have chosen are still appropriate now that the design is finalised.
Incorporating feedback well does not mean copying every suggestion you receive. It means weighing each piece of feedback against your specification and explaining why you accepted or rejected it. Explaining that reasoning is what separates a described change from a properly evaluated one.
These command words are not interchangeable. Describe asks for the main features of something, without reasons. Explain asks for reasons, so your answer needs a ‘because’. Evaluate asks you to weigh up strengths, weaknesses and alternatives and reach a supported judgement — a list of points with no judgement will not reach the top marks.