Purpose Of SAP Process Integration ( PI )
● Cross-system application integration, which does not focus on individual end-user actions. Applications can be company-internal, cross-company, SAP or non-SAP applications. The SAP NetWeaver usage type PI incorporates all functions that were previously a part of SAP Exchange Infrastructure (SAP XI).
● The modeling, administration, and automation of user-driven processes within SAP systems. From a technical viewpoint, a core function of the runtime is that you can save the state of a previously-modeled process and call it up at a later stage, if the process is to be continued as a result of a particular action or event. Since the execution of processes can be useful when integrating applications across system boundaries (without user actions), relevant functions within SAP NetWeaver are reused for this purpose. Together, the functions referred to here are known as Business Process Management.
Design
Applications in a heterogeneous system landscape run on a variety of different systems and platforms.In the long run, it is not cost-effective to integrate all these systems by using point-to-point connections because developers and consultants would need to analyze the implementation in each individual system to get a clear overview of the entire process. As a result, the architecture for application integration in SAP NetWeaver focuses on storing the relevant application integration information centrally. The following figure provides an overview of how to integrate applications with SAP NetWeaver.
At runtime, the Integration Server analyzes the data from the Integration Directory and the System Landscape Directory to process and forward messages from senders. In this way, you can develop applications that integrate SAP applications, external applications, marketplace applications, and middleware components from third-party suppliers. The architecture supports the integration of both internal company and cross-company applications.
Unbounded Processes
In the case of complex cross-system processes, stateless processing of messages with the Integration Server is sometimes not sufficient. Developers create integration processes in the Integration Repository to be able to correlate messages and execute more complex processes by means of loops. At runtime, the Integration Server executes these processes on the Business Process Engine and stores information about processes that have already been started and those that are not yet complete.
Embedded Processes
Using workflows in SAP NetWeaver, you can define user-driven processes and connect existing SAP applications to each other. A simple example of a workflow is the automated processing of a leave request: An employee creates a leave request which is then sent to the relevant manager. If the manager approves the request, the employee receives a corresponding notification and the leave is recorded in the system. The manager can also reject the leave request. You model the process flow and subsequent steps of user actions by using a model, which the Workflow Engine processes at runtime. Unlike unbounded processes, processes defined by using workflows are embedded in an SAP system.