Business organisations today are faced with the complex problem of dealing with
evolution in their software information systems. This effectively concerns the
accommodation and facilitation of change, in terms of both changing user
requirements and changing technological requirements. An approach that uses the
software development life-cycle as a vehicle to study the problem of evolution is
adopted. This involves the stages of requirements analysis, system specification,
design, implementation, and finally operation and maintenance. The problem of
evolution is one requiring proactive as well as reactive solutions for any given
application domain. Measuring evolvability in conceptual models and the
specification of changing requirements are considered. However, even "best designs"
are limited in dealing with unanticipated evolution, and require implementation phase
paradigms that can facilitate an evolution correctly (semantic integrity), efficiently
(minimal disruption of services) and consistently (all affected parts are consistent
following the change). These are also discussedComputingM. Sc. (Information Systems
