9.1.1 Introduction to Architectures

The term 'architecture' to most people conjures up images of fine buildings and drawings and plans of houses but, as systems engineers, we also use the same term. The term itself may be applied to any system that we develop but, the question is, exactly what is meant by an architecture? Also, once we have a clear understanding of what an architecture actually is, then at what phase of the system life cycle should it be produced and how should it be produced? This chapter looks at several definitions of the term 'architecture' and observes how this has evolved over time to be more encompassing than most people would think. Standards for architectures are also considered and, throughout, the use of the UML is discussed to see how it may help us to define, understand and validate our systems.

9.1.2 Architecture - Definitions

There are many definitions of the term architecture. For the purposes of this book, those from two different disciplines - software engineering and systems engineering - are compared and contrasted. The term is used widely throughout each discipline but, as with the scope of the two disciplines, an architecture in systems engineering is wider than one in software engineering.

First of all, consider the following definitions of 'architecture' taken from the world of software engineering:

• 'modules and how they are interconnected' [1].

• 'relationships among major...