Manufacturing, Production Processes and Workshop Techniques
Scale and process families
Production scale shapes process choice. One-off and batch production suit general-purpose tools and skilled labour; mass production justifies jigs, fixtures, dedicated tooling and automation; continuous production suits standardised commodities. Candidates should compare processes on accuracy, surface finish, setup time, unit cost, material waste and skill required.
Process families include: shaping (cutting, turning, milling, drilling, bending, moulding, casting, vacuum forming, laminating); joining (fasteners, adhesives, welding, soldering, sewing, knock-down fittings); and finishing (sanding, painting, powder coating, anodising, oiling).
Traps
- Claiming a process is "cheaper" without stating at what volume; setup costs dominate small batches.
- Ignoring tolerance and allowance; a joint needs clearance to assemble.
- Forgetting waste and offcuts when comparing material efficiency.
- Confusing a jig (guides the tool) with a fixture (holds the work).
Rule of thumb
Choose the least complex process that meets the tolerance and finish the function demands, at the expected volume.
Worked example: A short run of 20 plywood stools. CNC routing needs programming and setup but gives repeatability; hand cutting with a template jig is slower but avoids programming. At 20 units, a template jig plus a router is often the better balance. At 2,000 units, CNC nesting and dedicated fixtures win on unit cost and consistency. State the crossover reasoning explicitly.