Use of Leads and Lags

The use of leads and lags is a schedule compression technique that involves adjusting the timing relationships between tasks in a project schedule to optimize the overall duration. A lead is an acceleration of the successor activity, allowing it to start before its predecessor activity is fully complete. Conversely, a lag is a delay in the successor activity, meaning it starts after a certain period following the predecessor's completion. By strategically applying leads, project managers can overlap tasks that were previously sequential, thus shortening the project timeline without necessarily increasing resource allocation or costs. For example, in a software development project, testing (successor activity) can begin on completed modules before the entire coding phase (predecessor activity) is finished. By introducing a lead between coding and testing activities, the overall project duration is reduced. Careful adjustment of leads and lags requires thorough analysis to ensure that overlaps do not introduce undue risk or quality issues. It’s essential to maintain clear communication among team members to manage dependencies effectively. Misapplication of leads can lead to rework if the successor activity is started too early without adequate output from the predecessor. Using leads and lags as a compression technique is beneficial when there are constraints on adding resources or increasing costs. It relies on smarter scheduling rather than expanding the project budget. However, it should be applied judiciously to balance the benefits of time-saving with the potential risks to project quality and scope.