The production processes used in a manufacturing industry.

Industrial Practices – Production Processes in Manufacturing (Cambridge 9705)

This note follows the Cambridge International AS & A Level Design & Technology (9705) syllabus (2025‑2027). It integrates the design‑thinking framework, design principles, communication, societal & sustainability issues, health & safety, aesthetics, ergonomics and a systematic catalogue of materials with the core production‑process knowledge required for Section 13 – Industrial Practices.

1. The Design Process

1. Brief & Specification – define client/user needs, constraints (cost, time, standards) and success criteria.
2. Research & Analysis – market study, competitor review, material & process investigation, sustainability appraisal.
3. Concept Generation – sketching, mind‑mapping, morphological charts; aim for a wide range of ideas.
4. Concept Development – refine selected ideas, develop 2‑D orthographic drawings and 3‑D CAD models, consider ergonomics and aesthetics.
5. Design Specification – produce a detailed brief including dimensions, tolerances, material choices, finish, performance and safety requirements.
6. Prototyping – rapid‑prototype (3D printing, CNC machining, hand‑model) to test form, fit and function.
7. Testing & Evaluation – functional, durability, ergonomic and environmental testing; compare results against the specification.
8. Final Design & Documentation – issue full technical drawings, bill of materials (BOM), process plan and risk assessment ready for production.

2. Design Principles & Influences

• Good‑Design Criteria – functionality, safety, durability, ease of manufacture, cost‑effectiveness, aesthetics, ergonomics, sustainability.
• Design Movements – Bauhaus (form‑follows‑function), Minimalism, Retro, Futurism – each influences material choice, finish and production method.
• Scale of Production – bespoke (hand‑made), low‑volume (batch), high‑volume (mass‑production); affects tooling, tolerances and cost structure.
• Cost Drivers – material price, labour, tooling, energy, waste disposal; design decisions (e.g., modularity) can reduce life‑cycle cost.
• Fashion & Trend – colour palettes, surface finishes and form language change with consumer culture; designers must anticipate market cycles.

3. Communication in Design & Technology

• Sketch Techniques – freehand, perspective, exploded views; use of shading and hatching to convey material.
• Orthographic Conventions – plan, front, side views, section cuts, dimensioning (ISO/BS standards), tolerancing symbols.
• CAD & ICT Tools – 2‑D drafting (AutoCAD), 3‑D modelling (SolidWorks, Fusion 360), parametric design, BIM for large assemblies.
• CAM & Simulation – tool‑path generation, machining simulation, fluid‑flow analysis for casting, stress‑FEM for forging.
• Graphic Notation – symbols for finishes, welds, surface‑treatments, material call‑outs; essential for clear manufacturing instructions.

4. Design & Technology in Society

• Inclusive & Universal Design – design for a wide range of users (age, ability, cultural background); consider reach, grip, visual contrast.
• Cultural & Economic Impact – local sourcing, job creation, intellectual property, global supply chains.
• Product Life‑Cycle Perspective – extraction → design → manufacture → distribution → use → maintenance → end‑of‑life; each stage offers opportunities for improvement.
• Regulatory & Ethical Issues – CE marking, REACH, health & safety legislation, ethical sourcing of raw materials.

5. Sustainable Design

• Eco‑Design Strategies – design for disassembly, modularity, material reduction, lightweighting, use of recycled/renewable materials.
• Energy & Emissions – select low‑energy processes (e.g., cold‑forming vs. hot‑forging), recover waste heat, adopt renewable electricity.
• End‑of‑Life Options – recycling, remanufacture, composting (biodegradable polymers), take‑back schemes.
• Life‑Cycle Assessment (LCA) – quantitative comparison of carbon footprint, water use and waste for alternative process routes.

6. Health & Safety in Manufacturing

• Risk Assessment – identify hazards (thermal, mechanical, chemical, noise), evaluate likelihood and severity, implement control measures.
• Personal Protective Equipment (PPE) – safety glasses, hearing protection, gloves, respiratory masks, heat‑resistant clothing where required.
• Safe Work Practices
  • Machining – guard all rotating tools, use chip‑shields, verify work‑holding before start‑up.
  • Welding – ensure proper ventilation, use flame‑retardant blankets, check gas cylinders for leaks.
  • Casting & Forging – hot‑work PPE, thermal shields, emergency cooling stations.
  • Additive Manufacturing – handle fine powders in inert atmosphere, avoid laser exposure.
• Training & Supervision – competency records, lock‑out/tag‑out procedures, regular safety briefings.

7. Aesthetics & Ergonomics

• Visual Language – line, shape, texture, colour theory; use of finishes (polish, matte, anodised) to convey brand identity.
• Colour & Finish – selection based on material, environment (UV resistance), and manufacturing constraints (e.g., powder‑coat thickness).
• Anthropometric Data – reference to ISO 7250‑1 for hand‑grip, reach, seating dimensions; apply to handle design, control layout.
• Ergonomic Evaluation – posture analysis, force‑required testing, user‑testing prototypes for comfort and safety.

8. Materials & Components

9. Overview of Production Processes

Manufacturing processes are grouped into four main categories. For each, typical tolerances, surface‑finish grades and the digital tools that support control and optimisation are listed.

9.1 Forming (Shape without Material Removal)

1. Casting
   • Molten metal poured into a mould; solidifies to near‑net shape.
   • Typical tolerances: ±0.2 mm – ±0.5 mm; surface finish: Ra 3‑6 µm (as‑cast).
   • Digital links: CAD‑driven mould design, CFD & solidification simulation (MAGMA, ProCAST).
2. Forging
   • Plastic deformation under compressive force, usually hot‑forging.
   • Tolerances: ±0.05 mm – ±0.1 mm; finish after machining: Ra 1.6‑3.2 µm.
   • Computer‑controlled hydraulic presses; FEM for grain‑flow prediction.
3. Rolling
   • Material passes between rollers to reduce thickness or change cross‑section.
   • Hot‑rolling tolerance: ±0.5 mm; cold‑rolling: ±0.05 mm; finish: Ra 0.8‑1.6 µm.
   • PLC‑controlled roll gap, online laser thickness gauges.
4. Extrusion
   • Material forced through a die to produce continuous profiles.
   • Tolerances: ±0.05 mm – ±0.15 mm; finish: Ra 0.8‑2.0 µm.
   • CAD‑driven die design, real‑time load monitoring, closed‑loop motor control.

9.2 Machining (Material Removal)

1. Turning
   • Rotating workpiece cut by a stationary tool.
   • Tolerances: ±0.01 mm – ±0.05 mm; finish: Ra 0.2‑0.8 µm.
   • CNC with multi‑axis tool paths, adaptive feed‑rate control.
2. Milling
   • Rotating multi‑point cutter removes material from a stationary workpiece.
   • Tolerances: ±0.01 mm – ±0.03 mm; finish: Ra 0.2‑0.6 µm.
   • CAM software (Mastercam, Fusion 360) generates simulations, collision checks.
3. Drilling & Tapping
   • Rotary cutting tool creates holes; tapping adds internal threads.
   • Tolerances: ±0.02 mm – ±0.05 mm; finish: Ra 0.8‑1.6 µm.
   • Tool‑length measurement, automatic tool changers, coolant‑flow monitoring.
4. Electrical Discharge Machining (EDM)
   • Material removed by rapid electrical sparks; suited to hard conductive workpieces.
   • Tolerances: ±0.005 mm – ±0.02 mm; finish: Ra 0.2‑0.4 µm.
   • Closed‑loop voltage control, CNC programming for intricate cavities.

9.3 Joining (Assembling Components)

1. Welding (MIG, TIG, Arc, Spot)
   • Fusion of metals using heat and filler (or filler‑less).
   • Joint tolerance: ±0.1 mm; post‑weld finish after grinding: Ra 0.8‑1.6 µm.
   • Robotic cells with seam‑tracking sensors, real‑time arc monitoring.
2. Brazing & Soldering
   • Low‑melting filler metal bonds base metals without melting them.
   • Joint tolerance: ±0.2 mm; finish: Ra 1.6‑3.2 µm.
   • Temperature‑controlled furnaces, IR‑camera monitoring.
3. Adhesive Bonding
   • Polymeric or epoxy adhesives join like or dissimilar materials.
   • Joint tolerance: ±0.1 mm; surface preparation (abrasion, plasma) critical.
   • Automated dispensing robots, cure‑monitoring sensors (UV, temperature).
4. Mechanical Fastening (bolts, screws, rivets, clinches)
   • Removable joints using pressure or shear.
   • Tolerance governed by hole size: ±0.05 mm; surface finish as‑produced.
   • Torque‑controlled screwdrivers, vision‑guided rivet stations.

9.4 Finishing (Surface & Property Enhancement)

1. Heat Treatment (annealing, quenching, tempering, case hardening)
   • Alters mechanical properties via controlled heating/cooling cycles.
   • Hardness tolerance: ±5 HB; dimensional change ≤±0.02 mm.
   • Programmable furnace cycles, pyrometer feedback.
2. Coating (galvanising, powder coating, anodising, PVD)
   • Provides corrosion resistance, wear protection or aesthetic colour.
   • Thickness tolerance: ±5 µm; surface roughness: Ra 0.8‑2.0 µm.
   • Robotic spray booths, in‑process thickness gauges (eddy‑current, laser).
3. Surface Grinding & Polishing
   • Achieves high surface finish and tight dimensional control.
   • Tolerance: ±0.005 mm; finish: Ra 0.2‑0.4 µm.
   • CNC grinding with inline profilometers for real‑time monitoring.
4. Additive Manufacturing (3‑D Printing) – SLS, FDM, SLA, Metal SLM
   • Layer‑by‑layer material deposition; minimal tooling.
   • Tolerances: ±0.1 mm (SLS) to ±0.02 mm (SLA); as‑built finish Ra 3‑6 µm, post‑process to Ra 0.8 µm.
   • Integrated CAD‑CAM workflow, build‑simulation, laser melt‑pool sensors.

10. Comparative Summary of Key Processes

11. Linking Production Choices to the Syllabus Assessment Objectives

• AO1 – Knowledge & Understanding: Identify suitable processes, materials and digital tools; explain tolerances, finishes and health‑safety considerations.
• AO2 – Application: Select and justify a manufacturing route based on design specification, cost, volume and sustainability.
• AO3 – Analysis: Evaluate the impact of chosen processes on quality, environmental footprint and ergonomics; use LCA or cost‑benefit analysis.
• AO4 – Communication: Produce clear technical drawings, process flow diagrams, risk assessments and a concise written justification using appropriate terminology and notation.