If you are an inexperienced project manager, engineer, or designer, consider tripling your initial time estimates for projects. That’s not a slam. It’s just that new managers don’t take a lot of minutia into consideration when developing project time estimates. Experienced people have been through a lot of project cycles. They have seen a lot, and the know the hundreds of little things that can bog a project down or extend it long beyond all normal estimates. So if you’re new, triple the schedule until you know the details.