Iterative Design Process

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GCSE DT RevisionIterative Design Process

Key facts

The iterative cycle

Explore — research the problem. User needs, existing products, context, constraints. Methods: surveys, observation, analysis of existing products.
Create — generate and develop ideas. Sketching, modelling, CAD, prototyping. Select and develop most promising concepts.
Evaluate — test against specification. User feedback, performance testing. Identify what works and what needs improvement.
The cycle repeats — evaluation findings lead to further exploration and creation. Designs improve progressively.
Unlike a linear process, iteration acknowledges that no design is perfect first time.

Design briefs and specifications

Design brief — broad statement of the problem and context. Written by client.
Design specification — detailed, measurable criteria the product must meet. Written by designer.
ACCESS FM: Aesthetics, Cost, Customer, Environment, Safety, Size, Function, Materials.
Specification points must be measurable: not "must be safe" but "must comply with BS EN 71 toy safety standard."
User centred design — keeping the user's needs, abilities and context at the centre of every decision.

Exam questions — 3 questions · 9 marks · real AQA 8552 past papers

1 markIterative vs linearAQA 8552 style

What is the key difference between an iterative design process and a linear design process?

A Iterative design is only suitable for digital products

B Iterative design involves testing and evaluating at each stage and using that feedback to refine the design repeatedly; linear design passes through each stage only once

C Linear design always produces better results faster

D Iterative design does not require a specification

1 markACCESS FM — which categoryAQA 8552 style

A designer writes: "The product must not exceed 500g in mass." Which part of ACCESS FM does this satisfy?

A Aesthetics

B Cost

C Size

D Function

4 marksWhy prototyping mattersAQA 8552 style

Explain why prototyping is important in iterative design. What can designers learn from a prototype that they cannot from drawings or CAD? (4 marks)

Hint: Cover: ergonomics, structural testing, user feedback, manufacturing issues, visual judgement — things drawings cannot reveal. Give specific examples.

+40 XP

3 marksWrite measurable specification pointsAQA 8552 style

Write three measurable specification points for a reusable water bottle using ACCESS FM. Identify which category each relates to. (3 marks)

Hint: Each point must be measurable (specific number/standard). Label each with its ACCESS FM letter. Vague points like "must be safe" are not credited.

+30 XP

The iterative cycle

Design briefs and specifications

Module complete!