Answer
Because people are often involved in more than one activity, some way must be found to estimate how much time they spend in each activity. The most practical approach is often to ask employees how they spend their time. It is also possible to ask people to keep records of how they spend their time or observe them as they perform their tasks, but both of these alternatives are costly and it is not obvious that the data would be any better. People who know they are being observed may change how they behave.
Work Step by Step
As given above