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Internal Modernization of CICS and IMS TM

October 3, 2016

This week, I’ll finish my exploration of IT modernization by writing about CICS and IMS Transaction Manager (TM). Both are powerful transaction environments with a long history of internal modernization. However, more than their history is their pursuit of powerful functionality, high performance and innovation. 

In 1968 CICS was introduced as program offering that was designed to support roughly 50 Basic Telecommunications Access Method terminals. The transaction processing software was supported from Palo Alto, California, and wasn’t expected to be a strategic product as it had mainly assembler macros that supported a limited number of functions. In 1976, less than 10 years later, CICS/VS V1.3 was released after support moved to IBM Hursley in the U.K. The Hursley team sponsored the introduction of command level and the start of recovery/restart support. 

When CICS 1.3 was installed where I was working, I was writing COBOL programs running under CICS. Command-level programming changed everything. COBOL programmers stopped having to put assembler language macros into their COBOL code and do strange things like issue SERVICE RELOAD statements. With command-level, we no longer overwrote storage areas due to careless programming and stopped bringing down the CICS region with storage violations. 

After this, change and improvement and new functions were released at an impressive pace—from 1978 with CICS/VS V1.4 through 2015 with CICS Transaction Server (TS) for z/OS V5.3—25 releases over more that 35 years. What about CICS today: still releasing important functionality?
CICS TS for z/OS 5.3 builds on and compliments the capabilities that were delivered in earlier CICS TS releases. Importantly, this release completes over 300 customer requirements for CICS TS V5.

The latest release of CICS has new and enhanced capabilities that are delivered in three main focus areas:

1. Service agility: Enhanced support for Java and the WebSphere Liberty profile
2. Operational efficiency: Performance optimizations, enhanced metrics and additional security
3. Cloud with DevOps: New cloud and DevOps support to automate CICS deployments

CICS has its highest profile among financial institutions like banks and insurance companies who use it for mission-critical applications. Fortune 500 companies and many government entities run CICS, and it’s also widely used by many smaller organizations. Companies continue to use CICS because it changes and grows through internal modernization, and provides value and stability that’s needed for business critical applications. After all these years, it’s still running the race.
IMS DC, Later Named IMS TM
IMS has been a significant part of worldwide computing since its beginning in 1966 when 12 members of the IBM team, along with 10 members from American Rockwell and three members from Caterpillar Tractor, began to design and develop the system that was called Information Control System and Data Language/Interface (ICS/DL/I). This system was being developed to support the U.S. program to put men on the moon. The IBM team completed and shipped the first release of ICS in 1967 and in 1969, ICS was renamed to Information Management System/360 (IMS/360) and became available to the IT world. 

IBM developed an online component to support its database software to provide data communication access to the databases. The DL/I callable interface was expanded to the online component to support data communication transparency, making it easier to code the application programs. Message queue functionality was created to maintain the integrity of data communication messages and to provide for scheduling of the application programs. The online component that was developed ultimately became the Data Communications (DC) function of IMS, which became the IMS Transaction Manager (TM) in IMS V4.
IMS has successfully reinvented itself many times over those years and its list of state-of-the-art technological innovations is significant. All these years later—how is IMS doing? Customer acceptance of new IMS versions is a strong measure of its strategic importance. Overall, the growth of net new IMS licenses remained positive, fueled largely by expansions required because of mergers and acquisitions among existing customers in the Americas and Europe and the selection of IMS for new z Systems series servers in Asia. Over 90 percent of the top world-wide companies use IMS to run their daily operations in manufacturing, finance, banking and many other industries.

Here are some other interesting facts about how IMS is used include:

1. IMS manages a large percentage of the world's corporate data
2. Over 95 percent of Fortune 1000 companies use IMS
3. IMS manages over 15 million gigabytes of production data
4. $2.5 trillion (in U.S. dollars) per day is transferred through IMS by one customer
5. IMS processes over 50 billion transactions per day
6. IMS serves over 200 million users every day
7. IMS processes over 100 million transactions per day for one customer
8. IMS processes over 120 million transactions per day (7 million per hour) for another customer
* IMS can process 21,000 transactions per second (over 1 billion per day) using IMS data sharing and shared queues
* A single IMS has processed over 6000 transactions per second over a single TCP/IP connection

Most of my real-time transaction processing experience has been with CICS. Doing this research on IMS makes me wish that I had done more with IMS when I had a chance. Maybe there is some IMS DB and TM programming in my future.

Quick Recap
I hope that you have enjoyed this trip through modernization. In addition to this post on CICS and IMS, I have recently written the following posts on the modernization topic:

* What is Modernization of Existing Applications?
* Modernization of Existing Application for Mobility
* Modernizing the Data Repository of an Existing Application
* Modernization Applications Change
* Internal Modernization of COBOL and VSAM 
* Internal Modernization of DB2 and IMS DB

Posted October 3, 2016| Permalink