To actually deliver simplification, CEISAR describes in more details two simplification strategies: the Transformation Strategy and the Replacement Strategy.
Choose between two execution approaches:
- In the Big-Bang approach, migration is easier and faster but transition is more brutal and must be thoroughly prepared. It requires precise understanding of the Functions of the legacy and proper testing with a pilot phase on a product or organization subset of the Enterprise.
- In the Parallel Execution, the new System runs in parallel and in sync with the old System during a transition phase. It requires great care in the Architecture and costs more but reduces risk, improves progressiveness and often allows earlier business benefits.