How Will the System Be Designed?

Abstract

The actual design and development process of a system (or product) will vary according to the nature, type and size of the proposed system, its application, approved standards, and project management, but in general it wili be an iterative process, involving a number of stages. Many life cycles representing the design process are to be found in the literature; some of the more frequently cited will be presented in this chapter. It is worth pointing out that few systems or products are actudy designed from Start to finish, as demonstrated by these development life cycles. For example, some products will arise as a result of systems integration of a number of components, e.g. lawn mowers or Computer workstations, or wili involve the redesigning and modification of an existing product, e.g. Pyrex measuring cups (Younge, 1985), and ‘Reach’ toothbrushes (Kreifeldt and Hill, 1976). However, even if a system is developed from the conceptual stage through to operation, it is unlikely that its development will follow the neat packaging portrayed by the system life cycles that abound in the literature, primarily because they are an abstraction representing an ideal process, and the reality is likely to be very different, where economic, time and resource considerations have to be taken into account. In this sense, life cycles do not indicate the dynamic and iterative processes of system development as they unfold; they are inaccurate and simplistic, and merely represent a starting point. System building in the real world is subject to ‘constraints, interruptions, distractions, emotions, personalities and politics’ (Rubinstein and Hersh, 1984), and actual projects are not likely to be sequential or orderly, or linear processes in the rigid way that the life cycles suggest. When looking at the more commonly cited life cycles, the actual development and design of systems has to be considered within the conditions and influences already mentioned.