Product Design Factors
Six lenses on every product
The factors are purpose, function, aesthetics, sustainability, ethics and legality, and cost. Purpose is the problem the product solves and for whom. Function covers performance, usability, durability and safety. Aesthetics covers form, colour, texture, proportion and style. Sustainability covers material sourcing, energy, waste and end-of-life. Ethics covers labour, accessibility, cultural respect and honest marketing. Legality covers standards, intellectual property, labelling, and product safety law. Cost covers materials, labour, tooling, overheads, retail margin and lifecycle cost.
These factors conflict, and design is the management of those trade-offs. A cheaper material may reduce durability; a more sustainable finish may raise cost; a striking form may compromise ergonomics.
Traps
- Treating aesthetics as mere decoration rather than a functional and market factor.
- Listing factors without showing the trade-off.
- Ignoring legal obligations such as mandatory safety standards or patent search before copying a mechanism.
- Confusing unit cost with total lifecycle cost.
Rule of thumb
When asked to evaluate a design decision, name the factor improved, the factor compromised, and the evidence for the balance chosen.
Worked example: A children's toy. Purpose: imaginative play for ages 3-5. Function: no small parts, rounded edges. Aesthetics: bright, high-contrast colours. Sustainability: recycled HDPE, mono-material for recycling. Ethics and legality: complies with choking-hazard and labelling requirements, no misleading claims. Cost: mono-material simplifies moulding but limits colour options, so the trade-off is resolved with coloured masterbatch rather than multi-material assembly.