The Actual Plan consists of entries from the target plan, as well as entries differing from it. When you complete the target plan, entries from the target plan are transferred to the actual automatically by the system. You can enter actual data which differs from the target plan manually in the actual plan.
Then, when you save these entries, then all data relevant for time evaluation and time accounting is automatically transferred to each component. When you save the target plan, time data is transferred to Time Data Recording and Administration as well as Time Evaluation, thus, it is not necessary to create an actual plan.