IMS considerations

It is essential that you are familiar with using IMS and writing IMS applications.

When designing access programs that have IMS as a target back-end system, careful consideration must be given to the differences between CICS® and IMS under certain circumstances:

Message protocols
Use of response mode
Beginning and end of session
Effects of IMS restart and recovery features in a FEPI environment. (Because IMS is almost totally recoverable, this can present problems in the design of the FEPI application and some event handlers.)