Real World Advice: Handling Mainframe Field Expansion

Mainframe field expansion is an inevitability that all IT administrators face during the process of maintaining large information systems. While the concept is simple, the changes it introduces are enormously complex. Architects commonly overlook the importance of an array size, data type, or system constraint in the design phase.

By the time the limitation impacts the function of the business, the system and the inventory it manages may be enormous, resulting in a long and risky undertaking. In short, this effort impacts business logic, database access, application code, maintenance patterns, and much more. From large regional auto distributors to massive worldwide insurance companies, mainframe field expansion is an unavoidable part of growth and demands its place in your legacy technology support plan.

Mainframe Field Expansion: Can You Cope With The Scope?

So you have just realized that the primary key field used across all of your mainframe applications is about to be “too short” to accommodate a new business requirement. Understanding what software must change to accommodate this field expansion involves diving deep into the core application- and all others it touches. In addition, the analysis you do today will likely be flawed because the applications that require change are constantly being updated to support your business. DO NOT underestimate the level of analysis required. If you can get to the point where you feel the analysis is complete, the tedious task of making the software changes for the expanding fields requires a team of coders and a lot of time. Testers are also required and when you finish the project (many dollars later) you will still wonder what you missed.

Automation Is Your Salvation

mainframe field expansion, cobolOur Mainframe Field Expansion service leverages automated technology to reduce the time, talent and money required for the expansion of fields in your COBOL applications. Field Change Manager services keep you in full control while speeding the expansion analysis and instantly applying, after your approval, hundreds of changes across thousands of programs and millions of lines of code. When the process is complete, you can be assured that all of the code available was analyzed and that all changes approved were applied.

The Field Change Analysis Engine performs the same analysis that your teams would perform manually, reviewing and selecting lines of code to change across all of your applications. With the Field Change services, your application code is stored in a relational database. Intelligent software reads each line of code from the database, gathers the lines of code that define and reference the fields that you need to expand, and gathers, based on the logic in your programs, all other field definitions that could contain the expanding fields. The work is the same work that your analysts would perform, except that the Analysis Engine processes hundreds of lines a second, can execute 24-by-7 if needed, and can repeat the entire process any time.

Once the Field Change Analysis Engine completes its processing, your teams will be able to review all lines of code that will be impacted by the field expansion and review all additional fields that are affected by the field expansion. Easy to use spreadsheets allow you and your teams to spot-check and detail check any changes proposed by the Analysis Engine. You may have business reasons to delay changes to selected fields (for instance, because an outside vendor file is not yet expanded). You may want to revise maps or reports where the field expansion will cause “tightness” or “overlaps”. In any case, you and your team mark the changes you wish to apply.

The Field Changer then applies your approved changes and the source code is delivered back to you for installation, compile and testing. As with the analysis, the changes made by the Field Changer are the same changes that your team would make manually… only faster!  Each changed line is commented out and the new line is inserted with the change and a date marker in columns 73 thru 80. You get a full set of reports regarding the changes proposed, approved and applied. The process takes place over a matter of a few weeks rather than requiring many person-years for completion.

Know The Details, Reduce The Risk

mainframe field expansion, COBOLAlthough field expansion remains an almost unavoidable task in the maintenance of legacy systems and the businesses they support, the task can be complex and risky. These threats can be reduced drastically by automating the analysis, identification, and changes associated with a field expansion, ultimately providing return on investment through:

  • Removing barriers for growth
  • Continuity of key business processes
  • Easier application maintenance
  • Increased insight into data handling and managing capabilities of the legacy system

Automated Mainframe Field Expansion allows you to control the process and get the results you would expect from a manual field expansion project. The biggest difference lies in the time and the cost savings you can realize with tools and engines that do the work.


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