I agree with most of the posts above. however, at the end of the day, the company sign agreement and must be responsible to deliver on time. Customers don’t care what happens internally, They care about the results at the end from my experience. The last couple weeks, we have been studying different methods and documents that help to manage the project. It is very important to keep these docs up to date. Also, It is part of risk management. when there is a transition of project form one PM to another person. It doesn’t happen overnight and most likely there is a transition period when the transfer the task and other people take ownership so that the project doesn’t full apart. As well as management always planing for people backups just in case anything happens. It’s also management responsibility to help to solve such problems