Digital design and manufacture Computer aided design (CAD) — AQA A-Level Design and Technology: Product Design
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Digital design and manufacture Computer aided design (CAD) explained
CAD means producing and manipulating design information with software, while a manually generated alternative means drawing or modelling by hand.
Read the full explanation
To compare them fairly, judge both against the same task: for example, producing a dimensioned enclosure drawing that must be revised three times. CAD advantages include rapid, accurate editing, easy duplication and mirroring, parametric control so one dimension change updates the model, precise dimensions, reusable libraries, realistic rendering and direct links to CAM. Disadvantages include software and hardware cost, training time, file compatibility and version control, and the risk that a polished screen image hides design weaknesses.
Your focus
- Compare CAD with a manually generated alternative against a stated design task.
- Explain the consequences of named CAD features for the design process.
- Reach a justified judgement about which method suits a given context.
Digital design and manufacture Computer aided design (CAD) exam tips
Marking Points
- Identifies a genuine CAD advantage such as rapid editing, parametric updating, accuracy, easy duplication or a link to CAM, and explains why it matters for the stated task.
- Identifies a genuine CAD disadvantage such as set-up cost, training demand, file compatibility or version control, and explains the consequence.
- Identifies a genuine advantage of the manual alternative, for example speed for a quick concept sketch, low equipment need or direct tactile exploration.
- Identifies a genuine disadvantage of the manual alternative, for example slow revision, difficulty maintaining scale or inconsistent accuracy.
- Reaches a justified comparative judgement tied to the context, rather than asserting that one method is always better.
- Avoids treating a single feature as automatically decisive; recognises that the better choice depends on the task, stage and user.
Examiner Tips
- 💡Anchor the comparison to one concrete task so advantages and disadvantages are judged, not just listed.
- 💡Use paired language: state the feature, then the benefit or drawback, then the consequence for the design process.
- 💡Finish with a short justified conclusion that names the conditions under which each method is preferable.
Common Mistakes
- Listing CAD features such as layers or rendering without saying whether each is an advantage or disadvantage and for whom; correct by linking each feature to a consequence for the stated task.
- Claiming CAD is always faster or always better; correct by recognising that a quick hand sketch may beat CAD at the concept stage, while CAD wins on repeated accurate revision.
- Ignoring the manual alternative entirely and only praising or criticising CAD; correct by comparing both methods against the same task.
- Treating cost as only a CAD issue; correct by noting that manual work also has costs, such as draughting time and redrawing after changes.