In any SAP PS Project usually we get requirement related to Validations. So i am describing one of my Experience where Business does not want to create WBS beyond 4th Level.
Document describes How to create validation to prohibited Max WBS level code is 4 in project structure.
if client have kind of requirement like system prohibited to create <=4 level wbs in project.
hope this will help directly if any one get same requirement. generally this kind of requirement consultant face always
Validation: You can check values and combinations of values as they are being entered in the SAP environment. Validation rules are stored in the Rule Manager; as data is entered, the Integration Manager validates the data against the validation rules stored in the Rule Manage.