Phase 1: Mainframe Assessment
The assessment is a complete research and analysis project that outlines all legacy application and database conversion candidates. This step is vital to the automated conversion process and to successful modernization in general. Most organizations are surprised to find at the conclusion of the assessment phase, their legacy environments present themselves quite differently and are more complex than originally assumed.
During this stage, components are classified and listed in detail, while notes are attached to components requiring special attention. All application components are inventoried, classified by language, and cross-referenced, ensuring all missing components are collected and added to the inventory. The assessment phase results in a complete understanding of the legacy processing environment. This phase also includes discussing and reviewing the overall system test strategy and the division of converted code into work packets. Modern Systems defines a set of topics during the assessment phase that must be addressed prior to beginning the conversion process. In order to speed the modernization process, these topics are be addressed by team members who are best suited to understand the topic, the solution options, and any changes or activities that are required to address the “Areas of Concentration”. Once the areas of concentration are identified, Modern Systems works in lock-step with customer teams to address the areas about which they are most knowledgeable and for which they are best suited to implement a solution. Any additional areas of concentration that are identified during the course of the project are addressed and assigned in the same manner, to the most appropriate team.
Modern Systems' Mainframe Assessment Process
Phase 2: Database & Application Code Conversion
After the assessment is complete and a strategy for moving ahead is established, the automated conversion work is done; it spans both the application and data tier. First, the database is converted from the pre-relational to a relational format such as Oracle, SQL Server, or DB2. It includes the tasks required for unloading, transformation, and loading of data from the legacy database to the target environment. During the assessment, a data migration specification was created based on the structure of the existing data model and the database mapping rules. To accomplish this, Modern Systems generates programs/scripts to be used for the customer’s testing and migration of production data. Highlights of the data migration phase include:
- Non-relational database modeling utilizes a one-to-one default mapping approach into the new relational data model
- Deliverables include scripts/programs necessary for extract/transform/load (ETL) of data from the source environment to the target environment, as well as DDL for defining the target data model in the relational model, pre-delivery tested on customer-supplied test data, and data verification software
- Migration of data for on-site testing and production data
While the database conversion takes place, application code is loaded into our proprietary tools for conversion. At this stage, code included in the areas of concentration identified during assessment are handled with special care. Once complete, converted, functionally equivalent application code is delivered to the customer in a series of work packets, based on milestones determined during the assessment.
Automated Conversion covers online applications, batch programs, JCL members, etc. Modern Systems tests the converted code for functional equivalence, then delivers it along with any required frameworks to the customer for installation and on-site testing.
Phase 3: Test, Refresh, & Deploy
Modern Systems tests a subset of the converted code using a test plan with documented test scenarios provided by the customer. The customer writes the tests and runs them on the existing system to capture and record the expected results. Modern Systems then runs the tests against the same data on the converted system, identifies, investigates, and fixes discrepancies in the expected behavior of the modernized application. Pre-delivery testing consists of test cases picked from all available functional test cases in order to be representative of different parts of the applications. The automated conversion process does not require code freezes, which is a major risk reducer for customers, however, it is necessary to bring the new codebase up-to-date, therefore once pre-delivery testing is complete and any discrepancies in application behavior are resolved, Modern Systems performs a code refresh to ensure that any changes that took place in the legacy application environment during the conversion process are accounted for, converted into the target language and environment, and tested.
The Modern Systems teams work closely with customer teams to ensure a smooth and error-free transition night or weekend. Our teams also provide any required assistance during the 90-day warranty period following the deployment as well as post-conversion support of the modernized application, available at a fixed rate or in hourly buckets purchased as needed by the customer.