z/TPF Migration: Easing the Transition – Part 1

By Madhur Arya

With IBM planning to end support for TPF V4.1, there is an urgent need of migrating TPF 4.1 systems to z/TPF systems effectively. The two part blog will discuss the challenges faced by companies in z/TPF migration and the ways to overcome them. It will also present a detailed z/TPF migration approach and list the important considerations while doing this migration. I will conclude by sharing some best practices for a smooth z/TPF migration.

The changing IT landscape

TPF has evolved from the Airlines Control Program (ACP), a free package developed in the mid-1960s by IBM in association with major North American and European airlines. In 1979, IBM introduced TPF as a replacement for ACP — and as a priced software product..

TPF applications have been continually enhanced and remain at the core of majority of the world’s airline reservation, credit card authori­zation, network switching and front-end processing. More than 90 per cent of all airlines reservations and credit-card authorizations are processed using TPF. These applications are easily capable of processing tens of thousands of transactions per second.

The astronomical increase in the usage of reservation systems is placing an ever-increasing demand on TPF systems. Nowadays, travel reservations systems are not only accessed by travel professionals but are also by individuals on internet. This has resulted in a significant increase in number of potential users. To meet this demand, companies are moving to agile and flexible IT systems which are adaptable & responsive to evolving market needs.

This drives the need to integrate transaction processing systems into the service-oriented architecture (SOA) model which is not only more responsive to fast changing market needs but are also more cost effective. TPF systems, which were originally built to interact with Mainframes, now need to be integrated to new IT architectures that embrace open systems. This has led to the creation of the next generation of TPF, also called z/TPF.

z/TPF is a major upgrade to TPF, which embraces open systems & permits seamless integration of powerful TPF systems into SOA based IT architectures. The integration helps companies reap the benefits of mainframe systems & the agility of open systems. The benefits of z/TPF are not only limited to its agility & responsiveness but also includes extremely high level performance supporting tens of thousands of transactions per second along with superior reliability & scalability.


Challenges with z/TPF migration

Companies migrating from TPF to z/TPF face multiple challenges. Some of them are listed below:


1. Remediation (Resource intensive exercise) – Existing systems and software must be evaluated for remediation or replacement. This task is resource intensive and often incurs huge costs.

2. Transition Complexities – Since the TPF assembly code is cryptic and the available tools only partially automate the migration, a large amount of manual effort is required to achieve error-free code.

3. Seamless Transition – The transition needs to be seamless allowing existing systems to keep functioning since any disruption would result in loss to business.

4. Risk of Cost Overrun – Longer the duration of the migration, greater the costs involved. To reduce the financial impact, the migration must happen as swiftly as possible.

5. Keeping business logic intact – During large scale migrations, keeping the business logic intact is a challenge for most of the companies

So how does one address the challenges generally faced with z/TPF migration and ease the transition process?

An effective z/TPF migration requires expertise not just in the area of system integration but also in the ‘technical’ and ‘functional’ areas which would help keep the business logic intact and ensure a smooth business transition.

  • To deal with the transition complexities, the following tools are imperative to reduce manual effort  & deliver error-free code:
    • A listing comparison tool that would automatically compare the migrated machine code with the machine code in production
    • A dump E-mail trigger tool which would checks for issues in the Dump Reports(Log files) in the production, copy and test system & automatically sends email to the programmer thereby eliminating the need for checking the issues manually
    • A unit testing tool that searches the program along with the entry database and provides a well-defined path to reach the modified code in a particular program. The programmer can leverage this tool to identify the entry that would hit their modified code.
    • An EDIFACT simulator which would be used to simulate EDIFACT messages without the need of any external system.
    • A tool to help a developer to pre-screen his code in order to eliminate the basic errors related to coding and TPF standard guidelines.
  • There is a need to continuously monitor the dumps in production system during migration & fix the issues on high priority to affect a seamless transition without disrupting the current business
  • Milestones need to be defined along with the specified timelines at the start of the project which needs to be abided to. Any issues/defects halting the progress of migration should be fixed on priority basis.
  • The following steps should be taken to ensure that business logic is kept intact:
    • There should be a dedicated testing team to perform regression after migration
    • Any new changes incorporated during migration should undergo at least 3 levels of reviews viz. reviews by the onshore team, offshore team and the Subject matter experts.

In my next blog, I will be charting out a detailed z/TPF migration approach and sharing some best practices for a smooth z/TPF migration.

About the Authors

MadhurMadhur Arya is the CoE practice head for the TPF practice at IGT. Madhur holds a Bachelor of Technology degree from the University of Kurukshetra and has 15+ years of IT experience. He has been focussing on continuous improvement and implementing accelerators for development, maintenance and migration projects in the ALCS/TPF area. He can be reached at Mktg@www.igtsolutions.com

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