ACCESS TO ENGINEERING
Design is a problem solving activity in which the designer has to convert the customer’s needs for a product into a fully functional design.
The customer’s needs are presented in the form of a design brief. A design brief is a description in broad terms of the client’s needs which may contain any of the following:
• Client’s requirements
• Functional details
• Cost per item
• Market details
• Any special quality requirements
A design brief need not necessarily ask for the origination of a new product but may instead ask for the re-styling of an existing product or changing of a product to allow for a more cost effective production.
Sales and marketing use the design brief to establish precise information on the new or revised product’s requirements including the range and potential applications and environments in which the product will be used. Having established this information, Sales and Marketing must clearly define the exact requirements of the customer to ensure they are incorporated into the specification.
There is no easy way of solving the design problem and transforming the specification into a design solution.
Whatever the system whereby the initial specification is produced, the method used to translate it into the final design always follows a basic pattern and can be summarised in the following five steps.
1. Identification of the problem.
2. Analysis of the problem.
3. Design synthesis.
4. Design evaluation.
5. Development of the selected design.
Identification of the Problem
The total problem to be solved usually comprises several problems which are not necessarily directly related and which must be identified at an early stage in the design process. These problems can be classified as problems associated with:
Problems associated with Function
The problems associated with the function can be identified as the satisfaction of both primary function(s) and the secondary function(s). The secondary functions are those which must be fulfilled to enable the primary functions to be performed.
The definition of the primary function, or functions, must include the precise duty of the product or device, the accuracy with which it must be perform that duty and the circumstances in which the product will be used. These factors may limit the method of operation.
Other factors must be taken into account, such as the required degree of reliability of the product and the frequency off use. Although the customer usually considers reliability to be of primary importance, it usually increases the cost of a product. Often low costs can only be achieved if a low level of performance is acceptable. When a device is intended for use only in an emergency, it produces special problems because, although it will not be used often, or hopefully never at all, it must be completely reliable when it is required.
The secondary function should also be identified at this point, because the extent to which the primary function can be performed is usually controlled by the secondary functions. This can be illustrated by the special problem of providing the means to keep a person dry when shopping in wet weather. To fully satisfy this primary function, the device should completely envelop the user. However several secondary functions must also be satisfied for the device must be stored and easily transported when not fulfilling its primary purpose. It must also be easily and rapidly prepared for use in the event of a storm and must be not excessively inconvenient etc. The need to sacrifice the secondary function results in the device being an umbrella. It only partially satisfies the primary function, but it satisfies the majority...