When companies convert from an old AIS to a new one, there are a variety of ways to do so.  The four most common ways are:

Direct conversion – this is when the old system is ended right when the new system is implemented.
Parallel conversion – this is when both the old and the new system are operating “parallel” to each other during a transition/training period.
Phase-in conversion – this is where the new system rolled out in phases/pieces at an organization rather than rolling out the entire new system at the same time.
Pilot conversion – this is where the new system is tested first in one store/division rather than rolling out the whole new system across the entire organization at the same time.

QUESTION:  Why should the evaluation of a new AIS be a pre-planned and organized process? What is the benefit of doing so? Is that why there are four different methods? 

PLEASE POST 200 WORDS WITH REFERENCES