jr377 taking into account how long the built in buffer should be is an important point to bring up. As with all parts of the project this too will be a factor that impacts the budget. The extra time allotted for a buffer window must be factored into the overall project budget because that is more time the company needs to pay employees or contractees for a project that could have been finished sooner and a new project could have been started. This goes back to being aware of the company strategy and taking this into account while project planning. On the other hand, if the buffer window is planned properly there will be no delays and the project may even be finished ahead of schedule which always looks nice to your superiors.