IMS time-controlled operations

The time-controlled operations (TCO) allows you to initiate time-driven procedures for any IMS operation.

TCO relieves the operator of any task that is performed routinely or at a specific time each day. TCO can issue any IMS command that an operator can issue manually, except the /NRESTART and /ERESTART commands. TCO can start and stop telecommunication lines and message regions, monitor periodic system status, and notify users of system status. TCO uses scripts that call specific exit routines that schedule transactions, execute commands, execute message switches, and deliver deferred output.

TCO is upwardly compatible with and replaces IBM®'s Time Initiated Input Facility (TIIF) Field Developed Program.

TCO can generate any IMS input that an IMS operator can. Specifically, TCO can:

• Execute time-initiated commands, transactions, and message switches.

  Operators usually execute transactions and message switches manually at specific times. TCO can perform these functions and can also execute commands at specified times. Using TCO eliminates errors caused by incorrectly typing commands.

  Restriction: TCO cannot execute the IMS restart commands, /NRESTART and /ERESTART, or initiate conversational transactions. TCO also does not support full-function response mode or Fast Path input transactions.
• Start automatically during IMS initialization and terminate when IMS shuts down.

In addition, you can:

• Start, stop, and change TCO scripts without disrupting operations.

  After starting IMS with the time-initiated function, you can:

  • Stop TCO processing
  • Add, delete, change, or replace a TCO script
  • Start processing an existing script
  • Begin processing a new script
  • Start TCO if it was not started automatically at IMS restart

  These actions do not affect IMS operations.

• Restart the initial script DFSTCF during IMS restart.

  When IMS is restarted, TCO loads the initial script, called DFSTCF, for processing. If you stop TCO before IMS terminates, TCO will not start processing when IMS restarts.

• Test TCO scripts without interfering with online execution or shutting down IMS.

  Using the TCO Verification utility ensures IMS processes only error-free scripts and can do so without disrupting normal operations.

The following are possible implementations of TCO facilities:

• Starting IMS resources
• Handling peak loads
• Scheduling low-priority and non-IMS jobs
• Handling operations across multiple time zones
• Monitoring the system
• Updating user status
• Scheduling different procedures for different days
• Starting large IMS TM networks in phases to prevent resource contention or deadlocks
• Shutting down IMS