A service must manage its own resources if:
A service in which the application accesses files in a non-transactional way (that is, it does not includes COMMITs and ROLLBACKs), should be application managed.
A transactional application-managed service must contain all the transactional logic it needs, that is, it must complete with all resources either committed or rolled back.
Application-managed services are executed in a similar way to applications in a conventional execution environment. One of the main differences is that the process is not terminated at the end of execution of the service.