SAP Advanced Planning and Optimization (APO) is the planning component of mySAP SCM, the supply chain management solution provided by SAP.
SAP APO is used to make strategic, tactical and operational decisions and supports you in performing the following planning activities:
Demand Planning (DP)
Supply Network Planning (SNP)
Production Planning (PP)
Detailed Scheduling (DS)
Transport Load Builder (TLB)
Transport Planning and Vehicle Scheduling (TP/VS)
Global Available-to-Promise (G-ATP)
SAP's endeavor into the advanced planning solution market was with the name SAP APO. There are other APS solutions in the market from Oracle, Manugistics, i2 and a whole host of other companies providing specialized planning solutions
Over the years SAP has brought the SAP APO solution under a wider umbrella called SAP SCM. Since version 4.0 of APO it has been called SAP SCM. So in the release strategy of SAP you will find SAP APO 3.1 followed by SAP SCM 7.0
SAP SCM is a more complete solution that covers planning, networking, coordinating and execution. In addition to SAP APO, which is still the core of SAP SCM, there are other applications such as SNC (Supplier Network Collaboration - erstwhile ICH), SCEM (Event Management), EWM (Extended Warehouse Management) and SPP (Service Parts Planning).