IBM OS/390 User Manual

The first trial conversion starts with a complete fresh supply of the VSE
conversion inventory. Every three to four weeks, the mass conversion starts from
a fresh copy of the entire conversion inventory, in order to take into account the
last VSE maintenance modifications. Between two supplies, additional mass
conversions may be executed from the same supply, in whole or in part, in order
to take advantage of the latest custom modification improvements.

The first trial conversion is complete when all OS/390 programs, load modules,
and JCL are available for OS/390 tests.

The goal of these tasks is executing the converted jobs in MVS to verify that they
function as they did in VSE, and to correct software conversion errors or file
migration errors that generate test exceptions. Also during this phase full size
copies of the VSE production will be migrated to MVS, and in the process will
test the file migration procedure that will be used later on for switchover
rehearsal and actual switchover.

 1. To develop a broad base of knowledge as soon as possible.

A major resulting benefit of the testing phase is the experience and training
that is gained in the OS/390 environment. This is an excellent source of
hands on training in a soon to be real life environment. The testing
environment needs to include the use of the job scheduler, SMS, tape
manager and Report Manager.

Problems need to be identified as early as possible in order to provide the
proper lead time for their resolution. The by-products of thorough testing are
education, training, confidence, and success.

 2. To make the applications fail.

Testing is the process of working through execution time errors using the
applications, jobs and data you have converted and moved into the new
environment. Thorough testing and the elimination of problems are crucial to
a successful conversion.

Failure is good in the test environment; failure is not good in the production
environment. Therefore, the better the design and execution of the test
cases, the less chance for production failures.

There are typically three phases of testing associated with the test cycle for
applications. They are:

•

Unit Testing

•

System Testing

•

Parallel/Simulated Production Testing

OS/390 online application tests include:

•

Initialization tests which start each transaction to verify that the initial screen
comes up

•

Unit (or technical) tests are tests on a representative sample of transactions

•

System (or Functional) tests are scenarios of chained transactions
corresponding to application flows

VSE to OS/390 Migration Workbook