Here’s how it works. In a typical project, as time goes on, the ability to make changes that greatly impact resource allocation and design diminishes. At the same time, the cost of implementing changes increases as successive design choices create inflexibility and lock-in. The effort consumed by stakeholders and the allocation of resources typically follows a bell curve, so a large portion of the project unfortunately takes place during a time of diminishing impact and rising costs. Moreover, if you don’t get people involved early you tend to have a long tail of resource expenditure on after-the-fact customizations, modifications, and revisions.