To confirm the working hours of different work centers for a single activity, you can create multiple confirmations for the activity and use the appropriate work center for each confirmation. A confirmation is a function that allows you to record actual data for activities and activity elements, such as actual dates, actual durations, actual work, and so on. A work center is a parameter that defines where an activity is performed or who performs it. A work center can have various attributes, such as capacity, cost center, formulas, and so on. To confirm the working hours of different work centers for a single activity, you can create multiple confirmations for the activity and use the appropriate work center for each confirmation. This allows you to capture the actual work done by each work center separately and update their capacity requirements and costs accordingly. Reference: https://help.sap.com/doc/0f069b2e08b748f1b480d4c8b46c3c49/100/en-US/f373bb53707db44ce10000000a174cb4.html