Experienced executives must realize that computer-based changes in business processes are perilous. They should not trust a forecast that specifies a single target payoff number. The business case should deliver its summaries as add-ons to the previously approved financial budget. In this way the proponents can be accountable for their documented promises. The actual results would be then comparable to the revised budgets and performance plans at stated intervals, such as monthly, quarterly and certainly not more than annually.
All project plans are subject to change.
Approval of a proposed investment is only the starting point for a continually widening gap between the stated objectives and the capacity to deliver results. There are no plans that can remain unaltered while an innovative project is on its way. Customers will discover unanticipated improvements. They will change what they had originally requested. The completion schedule and the spending forecasts will also require modification.