The common scheduling tools and approaches assume a waterfall lifecycle. Since the problems with the waterfall lifecycle are well known, development teams have moved successfully to an iterative incremental development process known as The Spiral Model, but little has been published on who to estimate, schedule and manage such projects. This class identifies and provides an approach to estimate efforts and schedule projects that are run using the Spiral approach. The particular approach is defined as part of the ROPES process, but it applies to any kind of incremental development process.