The CONVTEK mass conversion approach is built upon the three fundamental principles of:

Mass Conversion

Automated Conversion

Repetitive Conversion

Mass Conversion

Mass conversion is the major distinction of the VSE to z/OS migration approach used by ConvTek.  Unlike a progressive conversion in which VSE application kernels are migrated one by one to z/OS, a mass conversion results in a single migration of all VSE applications to z/OS called the switchover.  Because the application switchover is highly automated, it can be accomplished within a weekend with minimum end-user service disruption and minimum end-user visibility.  Until Friday night, all converted applications run in production under VSE. By the end of Saturday, all converted applications run in production under z/OS. In the mass conversion, there is no overlap of VSE and z/OS production. This approach avoids many problems typically associated with a progressive conversion:

• Avoids coexistence of VSE and z/OS production material (code, JCL, and files)
  
• Avoids having to develop "bridges" between VSE and z/OS applications for:
  
  • Shared data files and databases
    
  • Automated job scheduling
    
  • Automated report management
    
• Avoids duplicate maintenance of programs in the process of being converted
  

• Avoids duplicate computer operations
  
• Avoids conversion patterns inconsistencies
  
• Reduces impact on applications and operations support

Automated Conversion

ConvTek uses proprietary conversion tools to automatically convert VSE JCL, code (COBOL, Assembler, RPG II, etc.), and files to native z/OS.  The conversion tools are exclusively designed for mass VSE to z/OS conversions.  Most specifics of the original VSE and final z/OS applications can be handled automatically by the tools, after they have been custom modified by coding specific installation options and exit routines.  Once custom modified, the tools convert the entire VSE production material to z/OS, in a short timeframe without manual intervention.  This process includes:

• Transfer, sort-out, and verification of the application inventory
  
• Modification of application programs and associated copybooks or subprograms
  
• Generation of z/OS load modules
  
• Conversion of VSE and POWER JCL streams including application and utility steps and associated SYSIN cards
  
• Generation of new z/OS JCL complying with local z/OS production standards and naming conventions
  
• Migration of VSE production files to z/OS

Besides significant workload and timeframe reductions, this methodology ensures consistent and reliable results, therefore reducing the scope of conversion tests.

Repetitive Conversion

The repetitive conversion is an iterative method in which the conversion is improved by refining the automated conversion process and the associated software instead of the generated z/OS material.  After a trial mass conversion, the generated z/OS material is tested for functionality in z/OS.  In the event that the conversion reports of z/OS tests indicate conversion flaws, the conversion software is custom modified to perform the conversion without flaws, and a new trial mass conversion is run again starting from a fresh copy of VSE source material.  This procedure is repeated until all conversion errors are eliminated.  The actual and final conversion and the switchover to z/OS do not start until trial mass conversions are error free.

By using a fresh copy of VSE source material for each trial mass conversion, all changes and modifications applied under VSE are automatically taken into account without having to follow up the VSE maintenance and to duplicate it in z/OS.  Therefore, it is not required to freeze or follow up development, enhancement, or maintenance of applications during the conversion.