SAP APO architecture consists of multiple components - Database, BI environment contains InfoCubes and Live Cache. InfoCubes are part of BI data mart and live cache is the main area where you keep all the data related to planning and scheduling. You can perform complex calculations in live cache and this improves the performance during calculations and reporting.
In a normal deployment scenario of APO, there is only one cache per installation.
Although there is a single cache, the data can be loaded in three different ways as per the application type.
Time Series − Suitable for Demand Planning and Supply Network Planning
As an Order with a category − Suitable for SNP, Production Planning/Detailed Scheduling, and Transport Planning and Vehicle Scheduling
ATP time series − Available-to-Promise
SAP BI functionality is primarily used by Demand Planning (DP), and depends on InfoCube which contains historical data. Processing of data is done in Time Series live cache and Supply Network Planning. PP/DS uses order live cache and SNP uses data for Time Series live cache.
Available-to-Promise relies on data in ATP Time Series Live Cache.
In SAP APO and ERP integration, most of the transactional data - Planned orders, purchase requirements - are created in APO, while data related to execution - Sales Order and Purchase Orders - are maintained in SAP ERP. For the integration of transactional data and history, a plug is provided by SAP. Plug-in contains a Core Interface (CIF) and also the interface to SAP BI structure.
SAP BI system gets data from Logistics Information System (LIS) in SAP ERP, which stores all the transactional data. Data is stored in InfoCubes with the use of periodic jobs scheduled as per the requirement of data load.
CIF provides an event-based trigger approach where data is loaded as and when required. For each event triggered, entries are created in Live Cache of SAP APO system.