Information Systems Architecture

“Architecture” is a popular term, yet different people use it for different things and with different meanings. In the 1980s and 1990s, architecture was close to becoming a buzzword. Apart from computer architecture, terms like enterprise architecture, information architecture, application architecture, communication architecture and more appeared to be trendy.

What exactly is an architecture? An architecture has very much to do with system structure. “Structure matters,” is a key statement in a wellknown book on software architecture [Bass 2003, p. 44]. An architecture defines the elements of a system, what they are meant to do, and their interrelations. Every non-trivial system has an architecture, whether it is implicit or explicit. A building has an architecture, a computer has an architecture, and software has an architecture. Booch calls a software architecture

intentional

if it has been explicitly identified and implemented, whereas “an accidental architecture emerges from the multitude of individual design decisions that occur during development [Booch 2006, p. 9].”

The study of software architecture as "… the principled understanding of the large-scale structures of software systems" [Shaw 2006, p. 31] emerged in the late 1980s. Since that time, intensive research in the field has made software architecture an essential part of system design and construction. An overview of the evolution of software architecture is given by Kruchten and coauthors [Kruchten 2006].