Interpreting float in resource constrained projects

The concept of float has been adapted for use in resource constrained projects. However, an important characteristic of such projects is that alternative resource allocations are often possible, resulting in a number of schedules with identical durations. An activity may be critical in one schedule but have considerable float in another. Alternative measures of float are explored which capture this flexibility of the resource constrained project. The practical interpretation of these measures is demonstrated in an analysis of a simplified software development programme.