ESR strategy for customers who have both SAP NetWeaver Composition Environment 7.1 (CE 7.1) and Process Integration 7.1 (PI 7.1)
What would be the ESR strategy for customers who have both SAP NetWeaver Composition Environment 7.1 (CE 7.1) and Process Integration 7.1 (PI 7.1)?
By Elena Doll, SAP NetWeaver Product Management, SOA Middleware
Organizations consist of different business domains like Marketing, Finance, HR and Research & Development. They focus on diverse tasks while working on the same goals for the company. Therefore, business software can be provided specially adapted to the needs of different business areas.
When businesses move to a Service Oriented Architecture (SOA), they usually move all their business domains to SOA domains. It frequently makes no sense moving just some business domains like Finance or HR to SOA. For a smooth communication between business domains it is always better to have a homogeneous landscape based on SOA.
Business domains moving to SOA use the Enterprise Service Repository (ESR) in a decentralized way. This means they run ESR and sometimes even PI separately for every business domain. With this approach, the domains try to keep the independency and decisive power of the domains. Sometimes a real motivation to work constructively together is missing. In most of the realized SOA scenarios, every business domain has its own local ESR and usually one global PI as shown in the diagram below.
Moving to SOA includes the integration of all systems through PI 7.1 and the service enablement of the IT systems by exposing all applications as services and storing them in the ESR. The services become the core assets and form the basis of the IT and the entire business. To access and use the services, customers need tools like the SAP NetWeaver Composition Environment or any comparable tool.
But let’s take a look at the most common scenario when customer run SAP NetWeaver CE 7.1 and also PI 7.1. In this case the customer is in possession of at least two ESRs or “buckets” to store services since SAP delivers the ESR with both products CE 7.1 and PI 7.1. Since services are stored in the ESR they could be tied to CE 7.1 or the PI 7.1.
The question the customers face is which ESR they should use? PI 7.1 is the centre or the heart of the whole SOA landscape integrating all the systems and organizing the communication. The ESR where all the services are stored should be close to the heart that is close to the bus (PI 7.1). Every service call or communication goes through PI 7.1 anyway and never through CE 7.1. CE 7.1 is not integrated or specific to any business domain. CE 7.1 as a tool can be also installed locally on any computer and is used as a tool for developers to build applications out of services, should access the repository just like any other tool from outside. PI 7.1 on the contrary is centralized integrating the whole business, its ESR is the core and should be the chosen one.