Design & Technology

Product analysis and design

Successful product design depends on asking the right questions about the proposed product. It is influenced by external factors such as what consumers want or need and features made possible by new materials or technologies.

Roles in product design

The client

The client employs the designer and sets the brief for the designer to work to. The client decides whether the product can go into production.

The designer

The designer plans the design of the product, and presents product ideas and prototypes [protoype: A full size working model of a design used for testing, development and evaluation. ] to the client. The designer needs to understand the market into which the product is to be sold.

The manufacturer

The manufacturer advises on the planning of manufacture. This means choosing the most effective method of production and the best organisation of equipment and people. The manufacturer also decides the best way to quality control the production process.

The user

The user is the person who the product is designed for. The product should meet their needs. Users want good quality products at a price they can afford.

Product analysis

Product design analysis means studying how well a product does its job. This involves answering the following questions

  • What is the function and purpose of the product?
  • What are the different parts of the product and how do they work together?
  • How does the product use shape [shape: The outline of a two-dimensional (flat) area. ], form [form: The three-dimensional shape of a solid object. ], colour, texture [texture: The 'feel' of a surface - its qualities of fineness, coarseness, smoothness, softness, hardness, shinyness etc. ] and decoration [decoration: Non-functional additions to a product to make it more interesting or appealing. Decoration may be done using line, colour, shape or additional materials. ]?
  • What materials and components [component: Working part of a product or system. ] are used to make the product?
  • Which processes were used to make the product?
  • Who would buy this product?
  • How well does the product do its job compared with other similar products?
  • What is unique about the product?

The table below will help you understand the meaning of shape, form, colour, texture and decoration.

PropertyExampleDescription
Shape

"Colour and form" 2004 Saville Associates Ltd

Shape can be 2D or 3D.
Form

"ORGONE LOUNGE" Marc Newson Ltd

Form is 3D - it is a solid object made up of shapes joined together.
Colour

"Flamp" produced by Galleria H20 (Barcelona). Design: Marti Guixe. Foto: imagekontainer

Colour is used to make a product more interesting and attractive.
Texture

Verde Chair 1993. Design: Fernando & Humberto Campana. Manufacturer: Edra (from 1998)

Texture is used to make an object more interesting. Surfaces are made 3D by the use of grooves, patterns and applying other materials such as fabrics.
Decoration

cushion

Decoration may be achieved by the use of different colours, shapes or materials. A decoration may be pasted onto a product, or be part of the material itself.

Product specification

A designer must make sure products meet the product specification. The product specification should be directly influenced by the analysis of research. This will ensure quality of design and that the end product is fit for purpose.

A specification is a statement that tells the designer exactly what the product has to do and what the design requirements are. A specification should include:

  • product function
  • overall dimensions
  • materials
  • an outline of the appearance of the product
  • user requirements
  • details of the source of power (if needed)
  • anthropometrics and ergonomics
  • possible production levels
  • legal requirements
  • environmental considerations and requirements

Anthropometrics is the study of the sizes of people in relation to products. For example, chairs used in schools need to be suitable for the average size of pupils in the schools.

Ergonomics is the relationship between people and the products which they use. Anthropometric data is used to help design products to meet ergonomic needs. Ergonomics also considers the force a person can apply, for example when using a tin opener, or the pedals of a car.

Development of ideas: working drawings

Working drawings contain all the information needed to make the design, including:

  • dimensions
  • details of components
  • materials
  • assembly instructions

Working drawings are normally done as orthographic projections.

Orthographic projection

Shows a 3D L shape

Orthographic drawings usually consist of a front view, a side view and a plan [plan: Scale drawing showing an object as seen from directly above. ], but more views may be shown for complex objects with lots of detail. A drawing board and parallel motion or T-square is used to project one view from another.

Orthographic drawing may be done using first angle projection or third angle projection.

An orthographic projection of the shape on the right is shown below.

Orthographic drawing showing a three-dimensional L-shape's sides in two dimensions. Both first andgle projection and third angle projection versions are shown

Sectional and assembly drawings

Some products may need a section drawing to give extra structural information, or an assembly drawing to show how parts fit together.

Sectional drawingA cross-section of a box shows how the individual pieces of wood are joined together



Assembly drawingTwo pieces of wood are joined by inserting screws



Development of ideas: modelling

Designers present their ideas to the user, client and manufacturer as models, mock-ups and prototypes.

  • Model - a scaled down graphic representation of a design.
  • Prototype - a life size working model of a design used for testing development and evaluation.
  • Mock-up - a model of a product built for study, testing and display.

Model making can be a very quick and cheap method of producing a prototype. Suitable materials include paper, card, foam board, styrofoamâ„¢, wire and 3mm MDF.

Users, clients and manufacturers use models to evaluate ideas and decide how well they meet their needs and how best to make it. Models are usually 3D but they can also be 2D drawings or CAD [CAD: Stands for Computer-Aided Design - the use of computers to assist in any of the phases of product design. ] simulations.

Modelling with CAD

CAD can be used when modelling and offers the following advantages:

  • Designs can be modelled on-screen and viewed from any angle.
  • Reaction to outside forces such as wind flow and pressure can be modelled.
  • Control sequences can be simulated [simulation: The artificial recreation of an event or activity, eg flight simulation software. ] before working on the actual material.

Rapid prototyping

Rapid prototyping is used to manufacture prototypes and small numbers of production quality parts. Plastics, metals, ceramics and paper can all be used.

Rapid prototyping is faster and cheaper than traditional prototyping methods, but the machines are expensive and it is only economical for short production runs.

Evaluating designs

Silver alessi juicer standing up

Alessi juicer designed by Philippe Starck. Photograph by Daniel Saxil-Nielsen.

Design ideas should be evaluated to make sure they meet product specification and are of a good quality. Evaluation can also check whether designs need to be changed to make them simpler to manufacture or enable them to be manufactured in higher quantities. To evaluate a design, consider:

  1. Does it meet the design need or situation?
  2. Does it meet the needs of the intended users?
  3. Does it fit the purpose for which it is intended?

Quality control

There are two aspects to quality control:

  1. Quality of design - how well the product meets the needs of the user.
  2. Quality of manufacture - how well the product has been made.

A product can be well-designed but poorly made, or well-made but poorly designed. This would mean it fails to meet the needs of the user.

Checking quality

A high quality product will:

  • meet the needs of the user.
  • use appropriate materials.
  • be capable of being maintained in a good condition.
  • have quality checks made at the appropriate time.
  • be made carefully and accurately.

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