ABSTRACT

In this chapter, readers will find a history of the Last Planner System, the functions it is used to perform, the principles which guide its use, and work underway to further develop the system. The Last Planner System was created as a reaction to the Critical Path Method, the guiding principle of which is to do highly detailed planning as early in a project as possible. The assumption that such planning is effective was challenged by the discovery in the early 1990s, that the percentage of weekly work plan tasks completed was unexpectedly low; typically around 50%. In response, practitioners were advised to limit project master schedules to the milestone level of detail, to plan in greater detail as you get closer to doing the work being planned, and to include those directly responsible for doing the work in planning how to do it. Users of the Last Planner System report that increasing reliability of handoffs encourages better planning and preparation, and hence better performance. One study found a 29% increase in productivity when the percentage of committed tasks completed increased from 50% to 80%.