You prioritize certain aspects depending on the type of the project. For example, in a customer project, the planned finish date is of major relevance. In contrast, in investment projects, the budgeted costs might be more important than other aspects. The aspects of planning are mutually dependent. For example, to keep a deadline, you need to allocate more resources. By doing so, you are likely to increase costs.
Assigning Human Resources to a Project

Internally processed activities are used to plan work that is to be carried out within your company.
You must define additional data for internally processed activities so the system can create capacity requirements and calculate costs for the following:
Work Center:
A work center is the place where an activity is carried out or work output is produced. A work center contains the scheduling and capacity data required for scheduling and capacity planning. A work center also contains data for costing.
Work:
Work is the planned output of machines or personnel to complete an activity.
Duration:
The duration specifies for how long an activity lasts.
Activity Type:
The activity type (and the cost center derived from the work center) specify a price for calculating the planned costs of an activity.
You can determine how much of the work center capacity is used for the activities. If necessary, you can use the Project Planning Board to level capacities. When you confirm activities during the project execution phase, you enter actual dates.