Rewrites mostly fail because business logic is assumed but never fully understood at a detailed level. Multiply by the size of the rewrite and things get out o

Rewrites mostly fail because business logic is assumed but never fully understood at a detailed level. Multiply by the size of the rewrite and things get out of hand quickly. The best way to go through a rewrite or upgrade is to get the business involved at the start and throughout the process. If you fail to do this when something is missed, overlooked or done differently and you will be at fault. If you include them it becomes a not feature not necessary.