6. Design Freedoms cont.

In particular, paradigm shifts that completely change the way of thinking about a product cannot normally be predicted but nevertheless often result in instances of over definition. Thankfully these radical changes in thinking occur relatively seldom but do highlight the need for continual re-evaluation of a product's definition throughout its development.

References to specific processes, components or methods usually indicate over definition. Of course some of these references may be necessarily specific because of business motive or legal requirement.

Under Definition

Under definition is another pitfall to avoid. It is readily identified by the designer as it requires a selection between several options. In most cases it is better to over define rather than under define as it leads to clarity of purpose and focused development. Under definition can become damaging and lead to unnecessary research. For example general reference to another document as a requirement, rather than to a specific clause, can result in time wasting research.

Avoid specifying a product's requirements in an indeterminate way. For example stating that "the product shall meet all the environmental conditions of the countries within which it is to be marketed", is a typical example of under definition. In this particular case, without a definition of the countries, the utilisation of the product, its performance in storage or under utilisation conditions, etc. the requirement is pointless and useless to the product developer. Statements of this nature are generally a result of laziness or lack of experience.

The ultimate under definition, is the complete oversight of requirements. This is much more difficult to protect against or detect and is one of the key concerns of this text as a check list. It is difficult to identify that a facility of a product is missing from its definition if there is no reference to it. It is for this reason that the individual responsible for product definition should, ideally, be different to that responsible for product concept development and market analysis. This allows there to be an independent auditor of the documented product definition.

The product definition, if properly prepared, will highlight all the design freedoms open to the designer as explicitly granted design freedoms. It will close off design possibilities in areas you wish to close off. It will open up design freedoms in areas you wish inventiveness to explore. Thus the product definition acts as a vehicle for avoiding unnecessary cost in a development programme.

According to the old saying "what can happen will", and so with granted design freedom. It is the license that a good engineer or designer will gladly embrace and follow to a logical conclusion. The key objective of the product definition is therefore to grant or deny design freedoms. Similarly the key quality criterion of a product definition is the achievement of a balance between over and under definition.