Authors' email and home pages
Perdita Stevens' email
and home page
Rob Pooley's email and
home page of our project.
The reengineering of legacy systems -- by which we mean those that
``significantly resist modification and evolution to meet new and
constantly changing business requirements'' -- is widely recognised as one
of the most significant challenges facing software engineers. The problem
is widespread, affecting all kinds of organisations; serious, as failure to
reengineer can hamper an organisation's attempts to remain competitive; and
persistent, as there seems no reason to be confident that today's new
systems are not also tomorrow's legacy systems.
A systems reengineering pattern is a description of an expert solution to a
common systems reengineering problem, including its name, context, and
advantages and disadvantages. We are principally concerned
with the problem how reengineering should proceed, rather than
with what the design of the reengineered artefact should be. The latter
problem seems to be adequately addressed by existing techniques (not least,
design patterns). A reengineering pattern embodies expertise about how to
guide a reengineering project to a successful conclusion. Because this is
not only or even principally a technical problem, the context of a
reengineering pattern must be much broader than that of a design pattern.
It includes business context as well as software context, and may even need
to take into account factors such as the budgeting procedures of the
organisation or the personalities of the managers whose support is needed.
In this position paper we explain this point of view, and briefly describe
two candidate systems reengineering patterns which are relevant to object
- that the main problem is not that the necessary expertise does not
exist, but rather, that it is hard for software engineers to become expert;
- that the diversity of the problem domain poses problems for
conventional methodological approaches;
- that an approach via systems reengineering patterns can help.