Design Process – Generation & Development of Ideas (IGCSE Design & Technology 0445)

1. The Full Design Process – Syllabus Overview

The Cambridge IGCSE Design & Technology syllabus is organised around a systematic design process. Every stage must be documented in the learner’s portfolio and linked to the three Assessment Objectives (AO1‑AO3).

1.1. Common‑Content Stages (Product Design)

1.2. Portfolio Checklist for Each Design Stage

Stage	What to record in the portfolio?
Observe a need	Problem statement, target‑user profile, market gap.
Design brief	Completed brief template (purpose, user, constraints, success criteria, sustainability).
Research & specification	Research‑log sheet, annotated bibliography, competitor analysis, specification table (functional, aesthetic, safety, environmental).
Generate ideas	Brain‑storming notes, mind‑maps, SCAMPER sheets, inspiration board, quick sketches.
Select & develop ideas	Evaluation matrix (weighted), refined orthographic/isometric drawings, CAD model, physical mock‑up.
Planning & risk	Work‑plan (Gantt), risk‑assessment form, tools & materials list, cost estimate.
Make prototype	Construction notes, step‑by‑step photographs, measurements, material usage record.
Test & evaluate	Test‑result tables, user‑feedback forms, comparison with success criteria, improvement suggestions.
Final design & communication	Full set of production drawings, CAD files, bill of materials, cost breakdown, reflective commentary.

1.3. Specialist Options – Quick Reference

Option	Core focus	Typical classroom task (example)
Resistant Materials	Properties, preparation, shaping, joining and finishing of wood, metal, plastics and composites.	Design a wooden‑plastic hybrid desk organiser that can be manufactured using CNC routing and solvent‑welding.
Systems & Control	Mechanisms, simple machines, electronic components, programming and control circuits.	Design a gear‑driven hinge for a portable desk lamp with a micro‑switch that turns the LED on/off.
Graphic Products	Visual communication, layout, colour theory, printing processes and digital illustration.	Create a branded packaging design for a reusable water bottle, including dielines and a printed prototype.

2. Design Brief – Template (Required for AO1)

Design Brief
Purpose / Need	_______________________________
Target user (age, abilities, context)	_______________________________
Constraints (size, weight, cost, materials, regulations)	_______________________________
Success criteria (function, ergonomics, aesthetics, durability, sustainability)	_______________________________
Sustainability targets (recycled content, energy use, end‑of‑life)	_______________________________

Students should complete this template before any research or idea generation. It directly addresses AO1 (knowledge and understanding of the design brief).

3. Research & Specification

3.1. Research‑Log Sheet (AO1)

Source	Type (book, website, interview…)	Key data collected	Relevance to brief
_________________	_________________	_________________	_________________
_________________	_________________	_________________	_________________

3.2. Specification Table (AO1)

Category	Requirement	Measurement / Standard	Justification
Functional	_________________	_________________	_________________
Aesthetic	_________________	_________________	_________________
Safety	_________________	_________________	_________________
Environmental	_________________	_________________	_________________

4. Generation of Ideas (AO2)

• Brainstorming – Record every suggestion, no criticism.
• Mind‑mapping – Visual network linking user needs, materials, functions and possible forms.
• SCAMPER – Prompt sheet (Substitute, Combine, Adapt, Modify, Put to other use, Eliminate, Reverse).
• Sketching – 30 s–2 min quick sketches to capture shape and function.
• Inspiration board – Collage of images, textures, colour swatches, patents.

4.1. Sample Evaluation Matrix (Weighted – AO2)

Criteria	Weight (%)	Concept A	Concept B	Concept C
Functionality	25	7	9	6
Cost	15	8	6	9
Ergonomics	20	6	8	7
Safety	10	9	7	8
Sustainability	15	8	5	9
Aesthetics	15	7	8	7
Total (out of 10)		7.3	7.1	7.5

Students assign a score (1‑10) for each criterion, multiply by the weight, and sum to obtain a total. The highest‑scoring concept is taken forward.

5. Development of Ideas (AO2 & AO3)

1. Use the evaluation matrix to justify the chosen concept.
2. Refine geometry, dimensions and functional details.
3. Produce a set of communication tools:
   • Hand‑draw orthographic and isometric views (to AO2).
   • Physical mock‑up (scale or full‑size) for ergonomics and fit testing (to AO3).
   • Parametric CAD model – allows rapid modification and generation of production drawings (to AO2 & AO3).
4. Test feasibility:
   • Simple prototype for fit/feel.
   • Digital simulation (stress, motion) where relevant (especially Systems & Control).
5. Record observations, justify design decisions, and iterate as required.

5.1. Typical CAD Workflow (Fusion 360 / SolidWorks / SketchUp)

1. Set up workspace – units (mm), default material, layer structure.
2. Create 2‑D sketches of primary profiles; apply geometric constraints and dimensions.
3. Extrude, revolve, loft or sweep to generate 3‑D geometry.
4. Add features – holes, fillets, ribs, chamfers, threads, cut‑aways.
5. Assign material properties; run simple simulations if required.
6. Generate a drawing sheet:
   • Orthographic, isometric and sectional views.
   • Detail enlargements, dimensioning, notes, BOM.
7. Save native CAD file, export PDF for the portfolio, and STL for 3‑D printing.

6. Communication Techniques

6.1. Drawing Techniques (AO2)

• Orthographic projection – Front, top and side views with true dimensions.
• Isometric / axonometric – 3‑D visualisation without perspective distortion.
• Sectional views – Cut‑away to reveal internal features.
• Detail drawings – Enlarged views of joints, fasteners or finishes.
• Annotation standards – Line types, dimensioning, symbols (ISO/BS 5455).

6.2. Physical Modelling (AO3)

Models test ergonomics, aesthetics and material behaviour before final production.

• Materials – Cardboard/foam board (quick concepts), modelling clay or polymer (organic shapes), wood/acrylic (robust prototypes), 3‑D printed PLA (functional parts).
• Modelling steps
  1. Select material appropriate to the development stage.
  2. Scale the model (commonly 1:5 or 1:10) and cut/shape components.
  3. Assemble, checking fit, balance and user comfort.
  4. Document dimensions, observations and any required modifications.

6.3. Computer‑Aided Design (CAD) (AO2 & AO3)

CAD provides precision, easy modification and the ability to generate both 3‑D models and 2‑D production drawings.

• Exact dimensions, tolerances and material properties.
• Parametric editing – change one dimension and the whole model updates.
• Automatic generation of orthographic, isometric and sectional views.
• Simulation tools for stress, motion and material usage (useful for Systems & Control).
• Export options: DXF for drawings, STL for 3‑D printing, PDF for portfolio submission.

7. Comparison of Hand Drawing, Physical Modelling & CAD

Aspect	Hand Drawing	Physical Modelling	CAD
Speed of initial idea capture	Very fast – sketches in minutes.	Moderate – material preparation needed.	Fast once software is mastered; slower for beginners.
Level of detail	Limited by skill; may lack precise dimensions.	Medium – good for ergonomics, limited for internal geometry.	High – exact dimensions, tolerances, internal features.
Ability to test function	None (visual only).	Good for fit, feel and basic mechanical movement.	Simulations possible (stress, motion, control circuits).
Cost of materials/equipment	Low – paper, pencils, rulers.	Variable – depends on chosen material.	Software licence or free student version; computer required.
Suitability for assessment	Essential for idea generation and communication (AO2).	Useful for development stage and ergonomic testing (AO3).	Required for final detailed design, manufacturing drawings and simulations (AO2 & AO3).

8. Linking the Design Process to the Assessment Objectives

Assessment Objective	Relevant Design‑process Stages	Typical Portfolio Evidence
AO1 – Knowledge & Understanding	Observe need, design brief, research & specification.	Brief template, research‑log, specification table, annotated bibliography.
AO2 – Application of Knowledge	Generation, selection, development, CAD workflow, drawing techniques.	Brain‑storming sheets, mind‑maps, evaluation matrix, refined orthographic/isometric drawings, CAD files.
AO3 – Analysis & Evaluation	Testing, evaluation, health & safety, sustainability, control.	Test‑result tables, user‑feedback forms, risk assessment, sustainability analysis, reflective commentary.

9. Assessment Criteria (Maximum 40 marks)

Criterion	What the examiner looks for (linked to AO)
Identify the problem & design brief	Clear need, target user, constraints, success criteria, sustainability (AO1).
Research & analysis	Relevant sources, competitor comparison, material data, specification table (AO1).
Generation of ideas	Range, originality, use of brainstorming techniques, visual records (AO2).
Selection & development	Justified evaluation matrix, refined drawings, CAD model, physical prototype (AO2).
Use of technology	Effective hand drawing, model making, CAD production, simple simulations where appropriate (AO2 & AO3).
Testing & evaluation	Systematic testing, user feedback, comparison with success criteria, identification of improvements (AO3).
Communication & presentation	Neat, labelled drawings, clear photographs, organised portfolio, reflective commentary (AO2 & AO3).
Health & safety, sustainability & control	Risk assessment, safe work practices, life‑cycle considerations, evidence of quality control (AO3).

10. Example Classroom Activity – Portable Desk Lamp (All Syllabus Elements Integrated)

1. Define the design brief (use the brief template)
   • Purpose: portable, battery‑operated desk lamp for teenage students.
   • Target user: 13‑18 yr, study environment, limited desk space.
   • Constraints: weight < 1 kg, height 30‑45 cm, LED source, battery life ≥ 8 h, recyclable materials, cost < £25.
   • Success criteria: ergonomic grip, stable base, easy battery replacement, no sharp edges, 50 % recycled content.
2. Research & specification
   • Complete a research‑log (three existing lamps, material data for aluminium, bamboo, PLA).
   • Populate the specification table (functional, aesthetic, safety, environmental).
3. Generate ideas (minimum 8 concepts)
   • Mind‑map linking “adjustable height”, “lightweight”, “LED”, “battery”.
   • SCAMPER each existing lamp idea.
   • 30‑second sketches for each concept.
4. Select two promising concepts using the weighted evaluation matrix (weights: Function 25 %, Cost 15 %, Ergonomics 20 %, Safety 10 %, Sustainability 15 %, Aesthetics 15 %).
5. Develop each concept
   1. Hand‑draw orthographic set + isometric view; annotate dimensions and material notes.
   2. Build a 1:5 physical mock‑up (cardboard/foam board) to test grip and balance.
   3. Create a parametric CAD model; run a simple stress simulation on the hinge.
   4. Generate a production drawing sheet (PDF) and an STL file for 3‑D printing a functional hinge prototype.
6. Test & evaluate
   • Record ergonomic feedback from three peers.
   • Measure battery life with a multimeter.
   • Compare results against the success criteria; complete an evaluation table.
7. Final communication
   • Full set of CAD production drawings, bill of materials, cost breakdown.
   • Reflective commentary linking each portfolio element to the relevant AO and assessment criterion.

11. Quick Reference Summary (Student Checklist)

• Complete the Design Brief Template (AO1).
• Log every source in the Research‑Log Sheet and fill the Specification Table (AO1).
• Generate at least 8 ideas using brainstorming, mind‑maps and SCAMPER; record sketches.
• Evaluate with the Weighted Evaluation Matrix – choose the highest‑scoring concept.
• Develop the chosen concept:
  • Hand drawings (orthographic, isometric, sections).
  • Physical mock‑up for ergonomics.
  • Parametric CAD model + simple simulation.
• Plan work (Gantt), assess risks, estimate cost.
• Make prototype, test, record data, and complete the evaluation table.
• Prepare final communication package (drawings, CAD files, BOM, reflective commentary).
• Cross‑check every portfolio item against the AO‑linked assessment criteria before submission.