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Part Two
Design
Purpose
Basic functions
Secondary functions
or use cheaper materials, or simplify processes. For example, Motorola used value engineering
to reduce the number of parts in its mobile phones from ‘thousands’ down to ‘hundreds’ and
even less, with a drastic reduction in processing time and cost.
Value engineering requires innovative and critical thinking, but it is also carried out using
a formal procedure. The procedure examines the purpose of the product or service, its basic
functions and its secondary functions. Taking the example of the remote mouse used previously:
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The purpose of the remote mouse is to communicate with the computer.
The basic function is to control presentation slide shows.
The secondary function is to be plug-and-play-compatible with any system.
Team members would then propose ways to improve the secondary functions by combining,
revising or eliminating them. All ideas would then be checked for feasibility, acceptability,
vulnerability and their contribution to the value and purpose of the product or service.
Taguchi methods
Taguchi methods
The main purpose of Taguchi methods, as advocated by Genichi Taguchi, 9 is to test the
robustness of a design. The basis of the idea is that the product or service should still perform
in extreme conditions. A telephone, for example, should still work even when it has
been knocked onto the floor. Although one does not expect customers to knock a telephone
to the floor, this does happen, and so the need to build strength into the casing should be
considered in its design. Likewise, a pizza parlour should be able to cope with a sudden
rush of customers and a hotel should be able to cope with early arrivals. Product and service
designers therefore need to brainstorm to try to identify all the possible situations that
might arise and check that the product or service is capable of dealing with those that are
deemed to be necessary and cost-effective. In the case of an adventure holiday, for example,
service designers need to plan for such contingencies as:
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foul weather – the need for bad-weather alternatives;
equipment failure – the provision of enough equipment to cover for maintenance;
staff shortages – flexible working to allow cover from one area to another;
accidents – the ability to deal with an accident without jeopardizing the other children
in the group, with easily accessible first-aid equipment, and using facilities and equipment
that are easy to clean and unlikely to cause damage to children;
illness – the ability to deal with ill children who are unable to take part in an activity.
The task is then to achieve a design which can cope with all these uncertainties. The major
problem designers face is that the number of design factors which they could vary to try
to cope with the uncertainties, when taken together, is very large. For example, in designing
the telephone casing there could be many thousands of combinations of casing size, casing
shape, casing thickness, materials, jointing methods, etc. Performing all the investigations
(or experiments, as they are called in the Taguchi technique) to try to find a combination
of design factors which gives an optimum design can be a lengthy process. The Taguchi
procedure is a statistical procedure for carrying out relatively few experiments while still
being able to determine the best combination of design factors. Here ‘best’ means the lowest
cost and the highest degree of uniformity.
Prototyping and final design
At around this stage in the design activity it is necessary to turn the improved design into
a prototype so that it can be tested. It may be too risky to go into full production of the
telephone, or the holiday, before testing it out, so it is usually more appropriate to create a
prototype. Product prototypes include everything from clay models to computer simulations.
Service prototypes may also include computer simulations but also the actual implementation
of the service on a pilot basis. Many retailing organizations pilot new products and services
in a small number of stores in order to test customers’ reaction to them. Increasingly, it is