Are you planning to migrate from JAVA compliant application servers (like IBM WebSphere Application Server, Apache Tomcat, Oracle (BEA) WebLogic Server, Sun GlassFish Enterprise Server (Sun Java System Application Server), JBoss Enterprise Application Platform, etc.) to SAP NerWeaver AS?
In this case it might be helpful to take a look at J2EE Migration Kit prepared by SAP. The kit is divided into four areas:
Process – goes through scoping an issues and risks to estimation effort to migration as is self.
Services – There are several different services that can SAP be involved in migration.
Tools – like estimators, migration guides, SAP NW Developer Studio plug-in
Resources – useful links to helpful for migration.
Here’s an example from migration guide how SAP NW components replaces original ones:
Whole kit is accessible at SDN site.