What are the strategic options for legacy system evolution? When would you normally replace all or part of a system rather than continue maintenance of the software?
What will be an ideal response?
strategic options for legacy system evolution are:
1. Abandon maintenance of the system and replace it with a new system.
2. Continue maintaining the system as it is.
3. Perform some re-engineering (system improvement) that makes the system
easier to maintain and continue maintenance.
4. Encapsulate the existing functionality of the system in a wrapper and add
new functionality by writing new code which calls on the existing system as
a component.
5. Decompose the system into separate units and wrap them as components.
This is similar to the solution above but gives more flexibility in how the
system is used.
You would normally choose the replacement option in situations where the
hardware platform for the system is being replaced, where the company wishes to
standardize on some approach to development that is not consistent with the current
system, where some major sub-system is being replaced (e.g. a database system) or
where the technical quality of the existing system is low and there are no current
tools for re-engineering.
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