There a multitude of ways schedule variance can occur within industry. We learned from the lecture that schedule variance is the difference between your earned value and planned value. Generally if you have a negative schedule variance, means you are behind schedule in the sense that what your project is worth today is worth less than what it was meant to be worth at that time. Some factors that could affect this are resources not performing up to par or resources leaving prior to the completion of the project. Additional factors could be testing within the project did not go according to plan that puts the project behind, this could also be a result of poor scheduling from the project managers standpoint since he or she did not prepare the schedule to be robust enough in the event of these mishaps.