The work of Christopher Alexander, a mathematician-turned architect, has had a subtle and yet a profound impact on the methodologies for the development of information systems in business. The main idea in architecture, espoused by Alexander, is that buildings and cities can be designed from the combination of certain basic patterns. Such patterns can be documented as diagrams which, in the architectural domain, specify spatial relationships. In the domain of business (and accounting) information systems development, the task is to create languages for describing and manipulating patterns to create systems that meet the needs of business.
In this note, we shall study the types of information systems used in the business, the way in which information systems are specified, and the various methodologies for the development of information systems.