Commercial processes: production techniques, quality control

IGCSE Design & Technology (0445) – Commercial Processes & Syllabus Overview

1. How the Exam is Structured

Cambridge assesses three Assessment Objectives (AO):

• AO1 – Knowledge & Understanding: terminology, principles, properties of materials and processes.
• AO2 – Application & Analysis: using knowledge to solve design problems, select materials, plan production, carry out tests.
• AO3 – Evaluation: judging solutions, suggesting improvements and reflecting on social, economic, ethical and environmental impacts.

Exam papers:

• Paper 1 (Common content) – 1 h 30 min, 30 % of total mark.
• Paper 2 (Common content – extended) – 2 h, 30 % of total mark.
• Paper 3, 4 or 5 (Specialist option) – 1 h 30 min, 40 % of total mark.

2. Common Product‑Design Content (AO1‑AO3)

2.1 Design Process – Full Syllabus Sequence

1. Identify a need / design opportunity – market research, user interviews, trend analysis.
2. Write a design brief – purpose, target user, key performance criteria and constraints (size, cost, sustainability, safety).
3. Develop a specification – measurable criteria (e.g., tensile strength ≥ 30 N, colour fastness ≥ 4, weight ≤ 200 g).
4. Research – existing products, materials, manufacturing processes, health & safety, environmental impact.
5. Generate ideas – sketches, mind‑maps, mood boards, simple CAD models.
6. Select a solution – use a decision‑making matrix (weighting of criteria, scoring, justification).
7. Develop the chosen idea – detailed orthographic & isometric drawings, exploded views, bill of materials (BOM), process plan and risk assessment.
8. Record‑keeping – data tables for dimensions, material properties, test results; clear labelling of sketches and CAD files.
9. Make a prototype – apply appropriate manufacturing techniques (see Section 3).
10. Test & evaluate – carry out relevant tests, record results, compare with specification, classify defects (critical/major/minor) and suggest realistic improvements.
11. Communicate the final design – specification sheet, presentation, cost estimate, user manual, and a reflective evaluation (AO3).

2.2 Health & Safety (HS)

General HS checklist (required for all options)

• Identify hazards – hand tools, power tools, moving machine parts, chemicals, noise, electricity.
• Carry out a risk assessment – likelihood, severity, control measures.
• Personal protective equipment (PPE) – safety glasses/goggles, gloves, ear protection, dust masks, safety footwear.
• Safe use of hand & power tools – correct grip, regular maintenance, guarding, emergency stop.
• Machine guarding – interlocks, safety curtains, two‑hand control where required.
• Chemical safety – labeling, MSDS, ventilation, proper storage.
• Electrical safety – insulated tools, residual‑current devices (RCD), clear wiring diagrams.
• Emergency procedures – fire extinguishers, first‑aid kits, evacuation routes, assembly point.
• Safety symbols – mandatory (e.g., PPE), prohibition (e.g., no smoking), warning (e.g., high voltage).

Textile‑specific HS (additional points)

• Guarded looms, knitting machines and cutting tables.
• Dust extraction for fibre handling.
• Safe handling of dyes, solvents and finishing chemicals.

2.3 Sustainability & Society (AO3)

When planning a product, consider the whole life‑cycle and its wider impacts.

Aspect	Key Questions for the Designer
Raw‑material extraction	Is the material renewable, recycled or responsibly sourced?
Energy use & emissions	What is the energy requirement for production? Can low‑carbon processes be used?
Water & chemical use	Are there water‑saving or non‑toxic alternatives?
Waste & end‑of‑life	Can the product be reused, recycled or safely biodegraded?
Economic impact	Is the product affordable for the target market? What is the cost‑benefit of sustainable choices?
Social & ethical issues	Are labour conditions fair? Does the product meet safety regulations?

Activity suggestion (AO3): Complete a “Sustainability Matrix” – weight criteria such as environmental impact, cost, durability and score each material/process against them.

2.4 Communication & Technology (AO1‑AO2)

• Hand‑sketching techniques – orthographic, isometric, perspective, section and development (net) drawings.
• British Standards (BS 8888) – line types, lettering, dimensioning, tolerances, and first‑ vs. third‑angle projection.
• Computer‑Aided Design (CAD) – 2‑D drawing, 3‑D modelling, virtual prototyping, and export for CAM (e.g., CNC, laser cutting).
• Technical documentation – specification tables, bills of materials, process flow charts, risk assessments, test data sheets.
• Digital image handling – colour management, file formats (DXF, STL, PNG) and preparation for printing or embossing.

3. Commercial Textile Processes (Common Content – Manufacturing)

3.1 Production Techniques

Technique	Key Features	Typical Products	Advantages	Disadvantages
Weaving	Interlacing warp (longitudinal) and weft (transverse) yarns on a loom.	Denim, canvas, upholstery, shirts.	High tensile strength, stable dimensions, good drape control.	Limited stretch, higher energy use, set‑up time for loom.
Knitting	Forming interlocking loops of yarn; circular or flat‑bed machines.	T‑shirts, sportswear, socks, sweaters.	Excellent elasticity, comfortable, rapid production.	Lower dimensional stability, prone to snagging.
Non‑woven	Fibres bonded mechanically (needling), chemically, or thermally (heat‑bonding).	Medical gowns, geotextiles, disposable wipes.	Fast, low‑cost, easy to vary thickness.	Generally lower strength, limited aesthetic options.
Dyeing & Printing	Colour added to yarns/fabrics; methods include piece‑dyed, yarn‑dyed, solution‑dyed, screen, digital, rotary.	Fashion fabrics, home‑textiles, technical textiles.	Wide colour range, pattern versatility.	Environmental impact, extra processing steps.
Finishing	Mechanical (calendering, brushing) or chemical (water‑repellent, flame‑retardant, anti‑static) treatments.	Outdoor apparel, upholstery, protective workwear.	Improved performance, added value.	Additional cost, potential chemical hazards.

3.2 Process Flow – From Fibre to Finished Product (AO2)

1. Selection of raw fibre – natural, synthetic or blended.
2. Spinning – converting fibre into yarn (ring, open‑end, air‑jet).
3. Fabric formation – weaving, knitting or non‑woven bonding.
4. Colouring – dyeing or printing.
5. Finishing – mechanical & chemical treatments.
6. Quality control – testing & inspection (see Section 4).

4. Quality Control (QC) – Ensuring the Product Meets Specification

4.1 QC Stages (AO2)

1. Raw‑material inspection – fibre length, fineness, moisture, impurity level.
2. In‑process checks – yarn tension, loom/knitting gauge, bonding pressure, colour consistency.
3. Post‑production testing – tensile strength, abrasion resistance, colour fastness, dimensional stability, flame retardancy.
4. Final inspection – visual defect detection, measurement of finished dimensions, packaging check.

4.2 Common Tests & Relevant Standards (AO1)

Test	Purpose	Standard / Method	Typical Pass Criteria (example)
Tensile Strength	Maximum force the fabric can bear before breaking.	ISO 13934‑1 (Strip method)	≥ 30 N for medium‑weight cotton.
Abrasion Resistance (Martindale)	Durability under repeated rubbing.	ISO 12947‑2	≥ 10 000 cycles for workwear.
Colour Fastness – Washing	Retention of colour after laundering.	ISO 105‑C06	Rating ≥ 4 on a 1‑5 scale.
Dimensional Stability	Shrinkage after washing/drying.	ISO 6330	≤ 3 % length, ≤ 2 % width.
Flame Retardancy	Resistance to ignition and after‑flame.	BS 5862‑2	No after‑flame after 30 s.

4.3 Defect Classification (AO3)

• Critical – makes product unsafe or unusable (e.g., large holes, toxic dye residues).
• Major – noticeably affects function or appearance (e.g., uneven dye, mis‑aligned pattern).
• Minor – cosmetic imperfections that do not affect performance (e.g., slight pilling, small loose threads).

5. Specialist Options – Choose ONE for Paper 3, 4 or 5 (AO1‑AO3)

5.1 Resistant Materials (Paper 3)

Focuses on the properties, preparation, shaping, joining and testing of four material groups.

Material Group	Key Physical & Working Properties	Typical Preparation & Shaping	Common Joining Methods	Sample Tests (AO2)
Metals (steel, aluminium)	High strength, good thermal conductivity, magnetic (steel), corrosion‑resistant (aluminium).	Cutting, filing, drilling, turning, milling, heat‑treating.	Welding, brazing, mechanical fasteners, adhesive bonding.	Hardness (Brinell), tensile test, impact test.
Plastics (thermoplastics & thermosets)	Low density, variable rigidity, good electrical insulation, melt‑processable (thermoplastics).	Cutting, heating & bending, moulding (injection, compression, vacuum).	Adhesive bonding, solvent welding, mechanical fasteners, ultrasonic welding.	Flexural strength, melt flow index, impact resistance.
Wood (hard & soft)	Good tensile & compressive strength along grain, anisotropic, biodegradable.	Sawing, planing, routing, steam bending.	Glue, nails/screws, dowels, mortise & tenon.	Modulus of rupture, density, moisture content.
Composites (e.g., GFRP)	High strength‑to‑weight ratio, corrosion‑resistant, directional properties.	Lay‑up of fibre mats, resin infusion, curing (oven or room temperature).	Adhesive bonding, mechanical fastening (if compatible).	Inter‑laminar shear strength, flexural modulus.

Design & Evaluation in Resistant Materials (AO3)

• Use a material selection matrix – criteria: strength, cost, weight, sustainability, ease of manufacture.
• Document preparation with a process‑flow diagram and a risk assessment.
• Carry out at least two simple tests (e.g., hardness and flexural) and record results in a data table.
• Compare results with the specification, discuss sources of error and suggest realistic improvements (alternative material, different joint, altered heat‑treatment).

5.2 Systems & Control (Paper 4)

Explores simple structures, mechanisms and electronic control systems.

Key Concepts (AO1)

• Loads & Reactions – dead load, live load, support reactions.
• Structural Forms – beams, frames, trusses, arches.
• Mechanisms – gears, pulleys, belts, levers, cams, linkages.
• Electrical Basics – voltage, current, resistance, Ohm’s law, series & parallel circuits.
• Control Elements – switches, sensors, actuators, simple programmable controllers (e.g., Arduino, PLC).

Practical Activities (AO2)

1. Design a simple lifting mechanism using gears and a motor; calculate gear ratio, speed reduction and required torque.
2. Build a basic circuit to power an LED with a switch and a resistor; verify voltage and current with a multimeter.
3. Model a truss bridge in CAD, calculate forces using the method of joints, and test a physical prototype for deflection and load capacity.

Evaluation (AO3)

• Compare calculated forces with measured values; discuss sources of error (friction, material tolerance).
• Assess energy efficiency – input electrical power vs. useful mechanical work.
• Consider safety, cost and environmental impact of chosen components (e.g., recyclable aluminium vs. plastic gears).

5.3 Graphic Products (Paper 5)

Focuses on the creation, communication and manufacture of two‑dimensional and three‑dimensional graphic products.

Drawing Standards (AO1)

• BS 8888 – line types, lettering, dimensioning, tolerances.
• Projection methods – first‑angle orthographic (UK standard) and third‑angle (US standard); specify which is used.
• Sectional views, exploded views, and development (net) drawings for packaging.

CAD & Production Processes (AO2)

1. Produce a scaled orthographic set (front, top, side) for a product using CAD software.
2. Generate an isometric sketch and a perspective view to visualise depth.
3. Develop a net (development) drawing for a cardboard box; calculate material usage, waste and cost.
4. Outline the manufacturing steps – printing, cutting, folding, gluing – and list required tools (die‑cutter, laser cutter, scoring blade).

Evaluation (AO3)

• Critically assess the clarity of drawings – legibility of dimensions, appropriate tolerances, correct projection notation.
• Analyse cost and waste of the packaging design; suggest alternative materials or layout changes to improve sustainability.
• Reflect on the environmental impact of inks, substrates and end‑of‑life disposal.

6. Integrating Quality Control Across All Options

Regardless of the specialist option, students should embed QC at every stage:

1. Define clear, measurable specifications (AO1).
2. Plan and record in‑process checks (AO2).
3. Carry out appropriate tests, use recognised standards and classify defects (AO3).
4. Include a reflective evaluation linking test results to design decisions, cost, sustainability and safety.

7. Quick‑Scan of the Notes vs. the 0445 Syllabus

Syllabus Block	How the Notes Measure Up	Missing / Weak Points	Actionable Fix
Common product‑design process	Full sequence present but brief on brief, specification, decision‑making matrix and record‑keeping.	No explicit design brief/specification; no matrix; limited test‑record guidance.	Added sections 2.1‑2.2 and 2.3 covering brief, matrix, data tables.
Health & Safety	General HS checklist added plus textile‑specific points.	Earlier version covered only textile hazards.	Inserted comprehensive general HS checklist (Section 2.2).
Sustainability & Society	Expanded with life‑cycle matrix and activity suggestion.	Lacked explicit prompts for evaluating environmental & economic impact.	Added sustainability matrix table and activity (Section 2.3).
Communication & Technology	Now includes BS 8888 drawing standards and CAD/CAM link.	Missing standards and CAD/CAM detail.	Inserted standards box and CAD/CAM note (Section 2.4).
Specialist options	More detailed outlines for each option, including AO1‑AO3 expectations.	Previous outline was too brief.	Expanded each option with key concepts, activities, evaluation points (Section 5).