Mainframe Communicates with the Outside World

By Ajay N.R.

In an age where today’s technology becomes history in a short span of time, it is interesting as to how Mainframe Technology has survived until now.  IBM not only continues to support legacy machines, but also continues to research on these machines. An example for this research is the launch of “zBC12” mainframe server.  

Current Trend

The days of mainframes being considered as completely isolated systems are long gone. In today’s world, a mainframe application is constantly being integrated with the distributed application.  The current trend suggests that CICS is a good candidate for integration. As a mainframe developer, good knowledge on CICS, especially from the Webservice point of view is gradually turning into a mandatory skill.

Having said this, the question arises as to why integration is the preferred approach when there are many other ways to modernize the Legacy Application?

To answer this, consider a simple scenario –You are running a Logistics application on mainframe to track the shipments. You have a character based CICS online application. This application has been running since 10+ years and a lot of code enhancements have been implemented. In short, the existing code has evolved into robust programs containing the core business logic. Currently, all the customers call in the Voice support to track their shipments.

 

What risk can we foresee from this scenario?

All though there is no flaw in the system, but with the market moving towards real-time system, customers may intend to have access rights to the shipment details from various devices, which may include cell phone, Web based application and other hand held devices.  If this is not provided, there may be a risk of falling behind in the race when compared to other similar competitors.

To avoid the risk, the common answer would be – “Let us eliminate the Mainframe and host our application on a Distributed platform”.  Easier said than done – Is this a feasible approach? Perhaps, now is a good time to have a look at the potential complication associated with the mainframe codes:

• Lack of Documentation – Since the code is evolved, documentation might be missing for many of the critical business rules.
• Lack of Developers – Developers who incorporated the modification to the code may not be present to provide proper guidance.
• Lack of Coding Standards – Code may be developed without proper coding standards. Below stated factors add to the complexity:

o   Improper field naming convention

o   Unreachable to code

o   Redundant logic

o   Inappropriate commenting standards

Hence, in order to Migrate/Re-engineer the mainframe application - Time, Cost and Risk factors  are very high.  If your mainframe application consumes more than 10,000 MIPS, then to generate  the estimate of time and cost for migration itself is a humongous task.  There are many cases reported where in the Migration/Re-engineering projects have been abandoned because of projects have crossed the maximum budget lines with diminutive progress on migration effort.

As a mainframe owner, how can you modernize the Mainframe Application without leaving out the mainframes? – Mainframe Integration.

The trick in Mainframe Integration is that the business rules associated with mainframe are published as a service with CICS acting as a Webservice provider - SOA. Code will undergo minimal changes only regarding how the data is received into and, released out of the Mainframe Logic. Since the business rules do not undergo any changes, the risk level drastically diminishes when it comes to integration. This gives integration an edge over all the other modernization techniques.

Conclusion

Since the risk involved is less in Mainframe Integration, it is the most of preferred modernization technique for midsize mainframe (5000-10000) MIPS and large mainframe (over 10,000 MIPS).  The current trend analysis shows that mainframe owners are implementing Mainframe Integration, even though the Integrated Application portfolio will have a mixture of technologies.