Scheduled variance equals earned value minus planned value. If the planned value increase making the solution negative then the project is behind in schedule. There is anything that can delay the project whether being testing problems, weather problems, employ problems, vendor problems, etc. In order to resolve, I believe the first decision should be holding a meeting where all departments/vendors must be aware of the problems. There should be insight from everyone where the project manger must consult with the customer before proceeding. A new schedule, more employ recruit to where is needed and etc. must be formed in order to fix the scheduled variance and return the project on track.