SAP Message /ISDFPS/FDPDAHHM021 - WBS element in force element of operation & not maintained

Diagnosis
A WBS element must be assigned in the force element of thedeployment. This WBS element serves as a cost collector forcost controlling or as a settlement object for plant maintenance.

Procedure
Assign a WBS element to the force element of the deployment.You can generate the WBS element from the force element(tab page "WBS Element").