Please refer to SAP notes below:
1. 1660821 - SAP WS&O by ClickSoftware - PI Adapter Installation Notes.
2. 1926902 - SAP Workforce Scheduling and Optimization 2.1.10
The Adapter consists of ERP Addon + PI Content. You can download the adapter (along with documentation) either from SAP Service Market Place or from ClickSoftware depending on where from you have bought the license.