Managing Change and Complexity: The reality of software development

This session will build on the method used to describe different forms of systems developed in the previous session. It will introduce some new terms, review the ways in which the approach to designing software has changed over time and discuss what is meant by a methodology.

Managing Change and Complexity - a summary

This session begins by introducing three important terms: reality, representations and descriptions, which are used to describe the transition from the initial specification to the final software. Together with the terms closed and complete from the previous session, these terms will be used as the basis for the classificatory system for methodologies that we will use for the rest of this module.

We the return to the history of computing and look at the way in which the approach to creating software has changed over time. In particular, we examine (a) the structured approach to software design that was dominant in the 1970's and 1980's and (b) the object oriented approach that followed it. We focus on what developers view as the biggest problems when developing software and observe that for structured methods validation is a problem where as for object oriented approaches the key problem is verification. We then use these observations together with the notions of closure and completeness to elaborate the four way description of systems we derived from theory in the previous session.

The session concludes with a brief examination of what is meant by the term methodology as it is applied to software design, and why we might want to use one when developing software.

Reading

Books

• See any of the books from the SDM books section

Articles

• Chapters 2 and 3 in D . Avison and G Fitzgerald, Information Systems Development: Methodologies, Techniques and Tools (3rd Edition), McGraw-Hill Publishing, 2002
• Brooks. F.P. No Silver Bullet: Essence and Accident in Software Engineering, in
  IEEE Computer, Vol. 20, No. 4. pp 10-19, April 1987
  or Chapter 16. in The Mythical Man Month: Essays on Software Engineering, Anniversary Edition, 1995
  or Information Technology and Society: A Reader. Ed, Heap, N. Einon. G. Mason. R and MacKay. H., Sage, 1995, pp 358 - 376.
• Cox. B.J. There is a Silver Bullet, in Information Technology and Society: A Reader. Ed, Heap, N. Einon. G. Mason. R and MacKay. H., Sage, 1995. p 377 - 399.

On-line Articles

• Some philosophic foundations for an environment for system building. Blum, B. I., and Sigillito, V. G. (1985). Denver, Colorado, United States: ACM Press.
  This paper examines the philosophical foundations of a system that will automatically produce what the author calls interactive information systems. It describes the process of software creation in terms of three basic transformations: from the "real world" to the problem statement; from the problem statement to the implementation and from the implementation to the system.

• Three paradigms for developing information systems. Blum, B. I. (1984). Orlando, Florida, United States: IEEE Press.
  This paper examines three paradigms for developing information system throughout the entire life cycle. It addresses the question of why such different approaches are taken to development, the role of software tools in systems development and the extent to which the entire process could be automated.

• Four Paradigms of Information Systems Development. Hirschheim, R., and Klein, H. K. (1989). Communications of the ACM, 32(10), 1199 - 1216.
  The authors argue that developing computer-based information systems involve a number of implicit and explicit assumptions based on the designers attitudes toward reality and how they can obtain knowledge about it. They examine four different approaches to developing information systems based on two contrasting examples.

• A Review of Information Systems Development Methodologies. Walters, S. A., Broady, J. E., and Hartley, R. J. (1994). Library Management, 15(6), 5 - 19.
  A concise historical review of the evolution of information systems development methodologies from Department of Information and Library Studies in the University of Wales.

Web pages

Systems

• The history of programming languages from Wikipedia.
• The history of software engineering from Wikipedia.
• The Systems Development Lifecycle from Wikipedia.
• The Spiral Model from Wikipedia.

Philosophy

• Epistemology, Logic and Ontology From Stanford Encyclopedia of Philosophy.
• Epistemology and Ontology from Wikipedia.

Lecture notes

The notes for this session are available as a presentation (in pdf format) - lecture notes for session 2