User exit routine specification removed from system definition

In IMS 15, to simplify the IMS system definition process and make system configurations more flexible, you no longer specify the use of certain user exit routines in stage-1 system definition macros. Instead, IMS loads these user exits dynamically during startup, and you can specify the use of many of these user exits by using execution parameters.

Documentation changes

The following table lists the publications that contain new or changed topics for the user exit routine specification removal enhancement. Publications that are not impacted by this enhancement are not included in the table.

Table 1. Links to topics that have new or changed content for this enhancement
Publication	Links to topics
Release planning	Migration considerations for removing user exit routine specification from system definition New, changed, and deleted messages and codes for IMS 15 User exit routine specification removed from system definition (new) (this topic)
System definition	Overview of the IMS system definition process Selecting the appropriate macros to define your system Data Communication macro statements System configuration macro statement Macros used in IMS environments COMM macro IMSGEN macro NAME macro TERMINAL macro TRANSACT macro Procedures used in IMS environments Parameter descriptions for IMS procedures FBP= through HSBMBR= procedure parameters FESEXIT= parameter for procedures LOCKMAX= through MNPSPW= procedure parameters MFSEXITF= parameter for procedures MFSEXITS= parameter for procedures SAV= through SUF= procedure parameters SIMEXIT= parameter for procedures TRACE= through YEAR4= procedure parameters USERMSGS= parameter for procedures DCC procedure IMS procedure
Communications and connections	IMS VTAM network administration > Editing and formatting IMS messages > Controlling output Sharing printers between systems
IMS messages and codes	DFS messages DFS1934E DFS3398E DFS4861W (new) DFS4862W (new) DFS4863W (new) DFS4864W (new)	G messages G117 (new) G118 (new) G119 (new) G120 (new) G121 (new)
Exit routines	IMS control region exit routines Guidelines for writing IMS exit routines > IMS callable services > Callable services Links with your exit routine and DFSCSI00 Transaction Manager exit routines Front-End Switch exit routine (DFSFEBJ0) Front-end interface block Description of the FEIB fields Timer facility Input Message Field edit routine (DFSME000) Defining edit routines Input Message Segment edit routine (DFSME127) Defining edit routines Message Switching (Input) edit routine (DFSCNTE0) Physical Terminal (Input) edit routine (DFSPIXT0) Physical Terminal (Output) edit routine (DFSCTTO0) Shared Printer exit routine (DFSSIML0) Transaction Code (Input) edit routine (DFSCSMB0) IMS system exit routines User Message table (DFSCMTU0)