What is user-centred design?

User-centred design (UCD) means keeping the needs of the people who will use a design at the centre of every decision, rather than designing for the designer's own taste or assumptions. It involves understanding real users (their goals, abilities and contexts), focusing on usability so the design is easy and pleasant to use, and gathering feedback by testing with users and acting on it. The result is a design that fits how people actually behave, which is why UCD overlaps so strongly with the empathise and test stages of the design process.

What are ergonomics and anthropometrics?

Ergonomics, also called human factors, is the study of how to design products and spaces so they fit the human body comfortably, safely and efficiently. Anthropometrics is a key part of it: the measurement of human body sizes (such as hand span, reach or seated height) and the use of that data, often as percentile ranges, so a design suits the intended range of users. For example, a chair height, a handle thickness or a doorway width are set using anthropometric data so most people can use the design comfortably without strain.

What is the difference between inclusive and universal design?

Both aim to make designs usable by as many people as possible, regardless of age or ability, and the terms are often used closely together. Universal design is the principle of creating one design that works for the widest possible range of people without needing special adaptation, such as a step-free entrance everyone can use. Inclusive design is the broader mindset and process of actively considering diversity (age, ability, language, culture) and removing barriers so people are not excluded. In short, inclusive design is the approach, and universal design is the goal of a single solution that works for everyone.

What are the 6 Rs of sustainable design?

The 6 Rs are a checklist designers use to reduce environmental impact across a product's life cycle. They are commonly given as Rethink (is the product needed, and could it be designed differently?), Refuse (avoid unnecessary materials or products), Reduce (use less material and energy), Reuse (design so the product or parts can be used again), Repair (make it possible to fix rather than replace), and Recycle (allow materials to be recovered at end of life). Applying the 6 Rs, together with life-cycle thinking, helps a designer lower impact from raw materials through manufacture, use and disposal.

What is the circular economy and how does it differ from a linear economy?

A linear economy follows a take, make, use, dispose pattern, where raw materials become products that end up as waste. A circular economy is designed to keep materials in use for as long as possible by reusing, repairing, refurbishing and recycling them, so that what would be waste becomes a resource for the next cycle. For a designer, circular thinking changes material choices and product design: choosing recyclable or renewable materials, designing for disassembly and repair, and avoiding mixed materials that cannot be separated, so the product feeds back into the loop rather than going to landfill.

SingaporeDesign Studies

Sustainable and User-Centred Design: O-Level Design Studies (NP05) module overview of user-centred design, ergonomics, inclusive and universal design, sustainability and the 6 Rs, the circular economy, and design ethics

A module overview of Sustainable and User-Centred Design for O-Level Design Studies (NP05): putting the user at the centre, ergonomics and human factors, inclusive and universal design, sustainable design and life-cycle thinking with the 6 Rs, the circular economy, and the ethical and social responsibilities of designers.

Generated by Claude Opus 4.89 min readSEAB-NP05Updated 2026-06-13

Reviewed by: AI editorial process; not yet individually human-reviewed

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How this module fits together
User-centred design principles
Ergonomics and human factors
Inclusive and universal design
Sustainable design and life cycle
The circular economy and materials
Ethics and social responsibility in design
A worked walkthrough: designing a public water dispenser
How this module is examined
Check your knowledge

How this module fits together

This module asks the two big "for whom and at what cost" questions of design. User-centred design keeps the people who will use a design at the centre of every decision, and sustainable design keeps the planet and society in view across a product's whole life. The two themes are deeply linked: a design that ignores its users or its impact is not a good design, however attractive it looks. Ergonomics and inclusive design sharpen the user side; the 6 Rs, the circular economy and design ethics sharpen the responsibility side. Throughout, the test of a strong answer is the same: can you connect a design decision to a real human need or a real reduction in impact?

This module covers each strand in turn, with its own focused page and practice questions. See the full set at /sg-o-level/design-studies/syllabus.

User-centred design principles

Start with the user. User-centred design principles covers understanding users, usability and feedback, and how to keep the user's needs central to design decisions. UCD overlaps directly with the empathise and test stages of the design process: you design for real people, then check with them.

Ergonomics and human factors

Designs must fit the body. Ergonomics and human factors covers ergonomics and anthropometrics - the measurement of body sizes - applied to design products and spaces that fit people comfortably and safely. A handle thickness or a chair height is set from anthropometric data so it suits the intended range of users.

Inclusive and universal design

Good design excludes as few people as possible. Inclusive and universal design explains inclusive and universal design and how to apply their principles so a design is usable by the widest possible range of people, regardless of age or ability. Inclusive design is the mindset; universal design is the goal of one solution that works for everyone.

Sustainable design and life cycle

Impact happens across a whole life. Sustainable design and life cycle covers sustainable design and life-cycle thinking, including the 6 Rs - rethink, refuse, reduce, reuse, repair, recycle - applied to lower a design's environmental impact from raw materials through manufacture, use and disposal.

The circular economy and materials

Sustainability points toward keeping materials in use. The circular economy and materials explains the circular economy, the difference between linear (take, make, use, dispose) and circular models, and how circular thinking shapes material choices - choosing recyclable materials and designing for disassembly and repair.

Finally, designers have duties beyond the user and the planet. Ethics and social responsibility in design covers the ethical and social responsibilities of designers, including honesty, inclusivity, safety and design for social good. Design is persuasive and powerful, so it carries responsibility for how it is used.

A worked walkthrough: designing a public water dispenser

Seeing all the strands applied to one design makes the connections clear.

Designing a public water dispenser for a community park

step Put the user at the centre

You observe who uses the park - families, elderly residents, joggers, children - and learn that current taps are awkward to reach and hard to operate with wet hands. This user understanding drives the design, not your own assumptions.

step Apply ergonomics and anthropometrics

You set the spout and button heights using anthropometric data so they suit a wide range of users, and choose a large, easy-press button operable with a forearm or a closed fist, fitting the body comfortably and safely.

step Make it inclusive and universal

You add a lower spout and bottle-filler so children and wheelchair users are not excluded, and use clear universal symbols rather than text, so one design works for the widest range of people without special adaptation.

step Reduce impact with the 6 Rs and circular thinking

You reduce material use, design parts to be repaired rather than replaced, and choose recyclable, separable materials so components can be recovered at end of life, keeping the product in a circular loop rather than sending it to landfill.

step Design ethically

You ensure the design is safe (no sharp edges, hygienic surfaces), honest in its signage, and serves the public good by encouraging refilling over single-use bottles, taking responsibility for the wider effect of the design.

How this module is examined

Tie decisions to users. Justify choices by real user needs and usability, not personal taste, and link UCD to the empathise and test stages.
Use anthropometric and inclusive reasoning. Explain how body-size data and inclusive thinking widen who can use a design.
Apply the 6 Rs and circular thinking. Reduce impact across the life cycle and explain how circular choices (recyclable, repairable, separable materials) differ from a linear take-make-dispose model.

Check your knowledge

A mix of recall and application questions covering sustainable and user-centred design. Attempt them under timed conditions, then check against the solutions.

Explain what user-centred design is and how it links to the design process. (2 marks)
Define anthropometrics and give one example of how it is used in design. (2 marks)
Explain the difference between inclusive design and universal design. (2 marks)
List the 6 Rs of sustainable design. (3 marks)
Explain the difference between a linear and a circular economy. (2 marks)
State two ethical responsibilities of a designer and explain why each matters. (4 marks)

Solutions

Q1: User-centred design keeps real users' needs, usability and feedback at the centre of every decision rather than the designer's assumptions; it links to the empathise stage (understanding users) and the test stage (gathering and acting on feedback) of the design process.
Q2: Anthropometrics is the measurement of human body sizes and the use of that data in design. For example, setting a chair height or a handle thickness from anthropometric data so it suits the intended range of users.
Q3: Inclusive design is the process of actively considering diversity and removing barriers so people are not excluded; universal design is the goal of a single solution that works for the widest range of people without special adaptation.
Q4: Rethink, refuse, reduce, reuse, repair and recycle.
Q5: A linear economy follows take, make, use, dispose, ending in waste; a circular economy keeps materials in use through reuse, repair and recycling, so waste becomes a resource for the next cycle.
Q6: Safety, because designs must not harm users (for example, no sharp edges or hazards); and honesty, because designs and their messaging must not mislead the user. (Inclusivity and designing for social good are also acceptable.) Each matters because design is powerful and affects real people, so the designer is responsible for its effects.

Sources & how we know this

Singapore-Cambridge GCE O-Level Design Studies (NP05) syllabus — Singapore Examinations and Assessment Board (2026)