HSC Design and Technology cheat sheet

Design process stages: identify need, research, generate ideas, develop and refine, produce, evaluate - each stage can loop back when evaluation reveals a flaw.

Design brief states the problem, constraints and target user; the design specification converts it into measurable criteria that ideas are tested against.

Primary research = first-hand data (interviews, surveys, testing, observation); secondary research = existing sources (standards, journals, competitor products, patents).

A design criterion is valid only if it is measurable - 'lightweight' becomes 'mass under 400 g'; unmeasurable criteria cannot guide evaluation.

Ideation tools: brainstorming favours quantity, morphological charts force combination of sub-solutions, SCAMPER prompts modification of an existing product.

Iterative prototyping (low-fidelity then high-fidelity) reduces risk by testing the riskiest assumption first, before costly tooling is committed.

Evaluation is formative (during development, to correct course) or summative (against the specification at completion); both must reference the brief.

Ergonomic data (anthropometric percentiles, reach, posture) and cognitive load principles convert user needs into dimensional design decisions.

Life cycle assessment (LCA) stages: raw material extraction, manufacture, distribution, use, disposal - impacts are summed across all stages, not just manufacture.

Cradle-to-grave counts impacts to disposal; cradle-to-cradle treats end-of-life as a new material input, so design for disassembly is decisive.

Sustainable design strategies: reduce material, choose renewables, design for repair, design for disassembly, extend product life, design for remanufacture.

The 6Rs (rethink, refuse, reduce, reuse, recycle, repair) rank roughly by impact; recycling is lower value than reuse because energy and quality are lost.

Embodied energy is the total energy used to produce a product; operational energy is used during life - for long-life products operational energy usually dominates.

Planned obsolescence (functional, technological, aesthetic) shortens product life; legislation such as right-to-repair mandates availability of parts and manuals.

Carbon footprint converts greenhouse gas emissions to CO2-equivalent using global warming potentials; it is a subset of LCA, not a full environmental measure.

Technology push (innovation drives the market) versus market pull (user need drives innovation) explains why some technically superior products fail commercially.

Material families: metals (ferrous/non-ferrous), polymers (thermoplastic/thermoset/elastomer), ceramics, composites, timber (hardwood/softwood/manufactured board), textiles.

Thermoplastics soften reversibly on heating and are recyclable; thermosets cross-link irreversibly and cannot be remelted - a key selection and recycling rule.

Mechanical properties to compare: tensile strength, hardness, toughness, stiffness (Young's modulus), ductility, density, and thermal/electrical conductivity.

Ferrous metals contain iron and are magnetic and prone to rust unless alloyed or coated; non-ferrous metals (aluminium, copper, titanium) resist corrosion better.

Manufacturing scales: one-off, batch, mass and continuous production - unit cost falls with volume, but tooling cost and flexibility trade off against it.

Processes by material: injection moulding and extrusion for thermoplastics; casting, forging and machining for metals; vacuum forming and laminating for sheet.

Joining methods: mechanical fasteners (reversible), adhesives (stress distribution but cure time), welding (permanent, heat-affected zone), knock-down fittings for flat pack.

Quality control checks output against tolerance; quality assurance builds process controls in so defects are prevented rather than detected.

The folio is evidence of process, not just outcome: it must show need identification, research, idea generation, development, production and evaluation in sequence.

Each folio entry should state what was done, why, what evidence resulted, and what decision followed - unannotated images do not demonstrate reasoning.

The design specification is a numbered, testable list; each criterion should later be matched to evaluation evidence in a table.

Project management tools: Gantt charts sequence tasks and dependencies, critical path identifies the longest dependent chain, milestones mark checkpoints.

Risk assessment records hazard, likelihood, severity and control measure; it is required for workshop production and must be updated as the design changes.

Testing and trialling data (user feedback, dimension checks, stress or function tests) should be recorded raw, then analysed against the specification.

Evaluation must address both the product (does it meet the specification?) and the process (what would be done differently and why?).

Referencing conventions (author, date, source) and a bibliography are required; unattributed images or copied ideas breach academic integrity.

Innovation types: incremental (improve existing product), radical (new concept), disruptive (cheaper/simpler entry that displaces incumbents), architectural vs component.

Intellectual property: patents protect function (20 years, requires novelty and inventive step), designs protect appearance, trademarks protect brand, copyright protects works.

Enterprise viability test: does the product solve a real need, at a price above unit cost, at a volume the market will buy, with a defensible advantage?

Start-up finance stages: bootstrapping, seed/angel, venture capital, crowdfunding - each trades equity or control for capital and validation.

Emerging manufacturing: additive manufacturing (no tooling, mass customisation, lattice parts), CNC automation, robotics, and digital twins for process simulation.

Emerging materials: smart materials (shape-memory alloys, piezoelectrics, thermochromics), biomaterials, graphene, and recycled composite feedstocks.

Emerging technologies: IoT-enabled products, AI-assisted generative design and topology optimisation, AR/VR for prototyping and training, renewable energy systems.

Technology adoption follows a curve (innovators, early adopters, majority, laggards); crossing the gap between early adopters and majority causes many launches to fail.