Manual process planning is used in direct planning of the business process inputs (activity inputs) as well as the business process outputs (quantities and prices). This requires, however, that the corresponding quantities on the input and output sides are known quantities. Manual planning is useful for scenarios in which you can determine these quantities without too much effort. Manual planning in actual is equivalent to directly confirming the corresponding quantities from activities and processes.
For those cases where measuring the relevant quantities requires unacceptable effort, we recommend indirect planning approaches such as: