Earned schedule (ES) is a strategy or practice that utilizes the concept of setting and tracking schedules on the basis of money or the number of hours worked rather than the more traditional approach of scheduling based on time increments. The idea is that at various stages in the life of any project or ongoing operation, the effectiveness of schedules based on time increments become less efficient. Rather than finding ways to work around those inefficiencies, using another basis for the construction of the schedule may acatually aid in successfully completing the tasks associated with the activity.
The idea of earned schedule is itself based on a more established concept known as earned value management (EVM). The development of an earned schedule involves the practical application of EVM to determine the most efficient manner in structuring the schedule. Based on factors relevant to the project at hand, using money as the foundation for the schedule and associating a currency value to each step of the process can make it possible to more accurately gauge the forward movement of the project. At the same time, choosing to base the schedule on the number of labor hours associated with each phase or step may also help in planning the sequence and duration of each step so that there is no loss of time or other resources. The concept of an earned schedule does not necessarily preclude the use of the more traditional use of time increments in arranging the schedule. Rather, the idea is to look at the project from more than one angle, then decide which combination of strategies to incorporate into the working schedule.
Creating an earned schedule based on the alternative values of money or labor hours can help to avoid some of the limitations sometimes inherent in setting a schedule based on time increments alone. Since the schedule is driven by factors other than a set number of minutes per task, there is room to deal with unanticipated events without necessarily derailing the schedule itself. From this perspective, the ability of project participants to work with a project manager and develop ways to overcome obstacles has the potential to make the most of all the skills and expertise found among the project team.
There is a difference of opinion regarding the effectiveness of the earned schedule. Proponents of more traditional methods cite the continued use of those methods over many years, as well as the fact that any issues that may occur using those methods can normally be compensated for at some point during the project. Advocates of the earned schedule note the broadened options for organizing tasks, including the ability to allow for more creative solutions to emerge that may in fact provide superior results.