Design briefs and specifications

A need is something necessary for the product to fulfil its purpose; a want is a preference that may improve its appeal or usefulness. A student may need storage that fits on a small desk but want a particular colour. Both matter, although a preferred colour cannot compensate for a product that does not fit.

Consider your own needs, wants and interests as well as those of your target user. Your interests might help you choose a worthwhile project or explore a style, material or technique. Your available time, skills and equipment also affect what you can make. However, when designing for someone else, your personal preferences should not replace their requirements. If you favour a tall organiser but the user needs a low product that does not obstruct their workspace, the user's need should guide the design.

Writing a clear, open design brief

A brief is a concise statement, not a long account of all your research. It should identify:

• what you intend to design and make;
• the target user or audience;
• the problem, need or purpose;
• where the product will be used;
• any important constraint established through investigation.

A broad context such as improving storage is only a starting point. The brief gives the project a more focused direction.

For example: ‘I will design and make a compact desk storage product for a GCSE student who works in a small bedroom. It should organise stationery, exercise books and digital accessories while taking up minimal desk space.’

This identifies a user, setting and purpose without fixing the solution. It could lead to a wall-mounted unit, modular trays or a foldable organiser. Exact materials, compartment arrangements and construction methods can be decided through designing and development rather than unnecessarily fixed in the brief.

Turning findings into a design specification

A design specification sets out what the product must do, be or have. Each point should be specific, justified and measurable or otherwise testable. A useful structure is requirement → reason → method of checking.

The following desk-storage examples illustrate how research findings can become useful criteria; they are not results from an actual investigation.

Choose categories relevant to the product: function, user needs, size, weight, safety, appearance, cost, materials, environmental impact, durability and maintenance. Also consider whether it can be made with the available time and equipment.

Appearance can be specified through an agreed colour range or style linked to user preferences. It need not always have a numerical target, but there should be a clear basis for judging it.

Separate essential criteria, which the product must meet, from desirable criteria, which would improve it. This helps you prioritise when one design cannot provide every preferred feature.

Recording how the product will be manufactured

A manufacturing specification provides the technical information needed to turn the developed design into a prototype. It should be clear enough for another maker to understand, rather than relying on details held only in your memory.

Relevant information includes:

• drawings, part dimensions and quantities;
• material types, thicknesses and components;
• tools, equipment and manufacturing processes;
• joining methods and finishes;
• the sequence of making and relevant safety precautions;
• tolerances and quality-control checks.

For example, a design criterion might require the product to fit inside a school locker. A manufacturing instruction could specify: ‘Cut the back panel from 6 mm plywood to 260 mm × 180 mm, with a tolerance of ±1 mm.’ This gives the maker a material, thickness, part size and permitted variation. It describes one part, not the whole manufacturing specification.

Checks should occur while errors can still be corrected. Measuring mating parts before assembly helps establish whether they will fit; checking only after assembly may be too late.

Using the specification to guide development

Refer to the design specification when comparing ideas, selecting materials, testing models and evaluating the final prototype. A design that looks attractive but fails an essential storage or safety requirement does not successfully solve the task.

Use measurements, tests and user feedback to judge each criterion. The brief and specifications remain working documents: if evidence requires a change, record the change and its reason so that design decisions remain traceable.