SAP xMII is a powerful tool for developing manufacturing composite applications but still lacking in one single point – a local persistency layer for the plant floor data. This scenario can be addressed well by the integrating xMII with CAF Core – the persistency and data modeling layer for Netweaver based composite applications.
Composite Application Framework has a local persistency layer at the J2EE WAS which is called the CAF Core layer. Here we can do data modeling and persist the data through a uniform data persistent framework based on JDO. CAF Core offers entity services which represent business objects. The entity services are created in the CAF core layer using a graphical tool in Netweaver Developer Studio (CAF Perspective) based on the business data structures. The data can be pulled from enterprise systems like ECC using RFC/BAPI/Web Service or from legacy systems using web service. Applications services are modeled as a wrapper over the entity services implement additional custom logic over the standard CRUD (Create, Read, Update, Delete) methods. Custom methods can be created to add, update or query data to and from the CAF persistency layer. The Application service can be exposed as Web Service as well, so that all it’s methods becomes web service methods. (For more information on creating CAF Core application services and exposing them as web services please refer this document).
Once the CAF Core application service methods are exposed as web services those can be used by xMII to persist data locally. The data structures are modeled using the entity services. So that xMII can collect data from various sources like plant floor MES and legacy systems as well as backend ECC, merge and manipulate them as required and persist them in the CAF Core layer. The diagram below explains the architecture of xMII integration with CAF Core.
Now lets look into the various steps to integrate CAF Core services with xMII:
- Creating the CAF Core Entity Services: Create a CAF Core project (LocalDevelopment or NWDI based) using Netweaver Developer Studio. Create the Entity Services and add attributes based on the data model required for the persistent data. The CRUD methods for each entity services are generated automatically. Additional query methods can be generated.
- Creating the CAF Application Service: Create the Application Services based on the entity services created in the previous step. Add the entity services as dependents in the Application service. Create new create, update, delete and read methods using the wizard. Add custom logic in the methods created if required and call the entity service methods from the app service methods to access the persistent data.
- Exposing the Application Service as Web Service: After implementing the application service select the application service and check the Remote Enabled Service option in the General tab. Save all metadata and then create a new web service implementation for the application service by selecting Web Service option from its context menu. Select the methods to be exposed as web service method and follow the steps guided by the wizard. The application service is now ready as a web service.
- Configuring the xMII BLS transaction: The CAF web services can be called by the Web Service action block in the xMII BLS transaction. To call a CAF Core web service add a Web Service action block in the xMII BLS transaction editor and open the configuration wizard of the action block. Enter the Web Service WSDL URL and the user name and password to access the Web Service. Select the ports and operations in the subsequent screens and finally click on Finish. This makes the xMII Web Service action block ready to call the CAF Core Web Service. Call the create and update methods to add and update the data and the read methods to read the data from CAF Core persistency layer.
This makes a data modeling and persistency layer ready for xMII thus making a true composite. In my The Making Of A Powerful Composite : Integrating SAP xMII With Guided Procedure I’ll discuss how to integrate xMII with CAF Guided Procedure to effectively manage manufacturing work processes making the story complete.