IBM Branch Transformation Toolkit 5.1 Migration and Usage Guidelines

Chapter 2. Migration strategy 33

2.4.6 Code preparation

The amount of time you must allocate to coding practices is a significant factor to

consider when evaluating migration complexity. To migrate application code

more easily and more efficiently, we recommend that you refactor the code

before migration. If you apply the refactoring discipline properly, you can handle

code migration more easily because the code will be simple and clean.

Regardless of the development methodology you choose, refactoring improves

the overall code quality. Migration is good time to reexamine and refactor your

code.

To reduce the effort of migration work, remove the code that is not used. If you

have completed the refactoring process before migration, it becomes easier to

exclude the code that is not a part of the migration effort. The practice of

removing what you do not use can also be extended to the runtime environment.

Unused resources such as data sources should be removed as a matter of

practice.

Coding practices can have a direct impact on the complexity of migration. Well

designed and architected coding is generally easier to understand and modify.

Layered architectures are a huge win when change is required.

The new version of Branch Transformation Toolkit also supports more recent

versions of the relevant specifications. In anticipation of an upcoming migration,

you can update the existing code to conform to the most recent version. Branch

Transformation Toolkit 5.1 supports multiple versions of the related standards

such as J2EE and BPEL, but in anticipation of a migration, you may consider

updating your application to comply with the most recent versions of the

specifications that run on Branch Transformation Toolkit V5.1.

2.4.7 The migration plan

The migration plan is what should guide you during the entire migration process.

The various tasks at every stage should be captured and documented in the plan

and we recommend that all migration activities follow the plan.

However, the migration plans should also be flexible. As part of the migration

assessment, you should document the risks and unknowns that can impact your

plan. Assume that uncertain issues will occur during the migration process. For

example, a common mistake is factoring in some time for testing but not enough

time for fixing problems. Be sure to allocate enough time in the plan to fix the

problems encountered.

Scheduling is an important part of the planning process. It helps chain migration

tasks together. Remember that many tasks can be completed in parallel.

34 IBM Branch Transformation Toolkit 5.1 Migration and Usage Guidelines

Figure 2-2 shows the skeleton of a high-level migration schedule. Use this as a

guide to make your own schedule appropriate to the situation for your site.

Figure 2-2 Sample migration schedule

Documentation is an important part of the planning process. It helps make things

simple by separating the description of tasks from the scheduling of their

application. There are a number of popular ways in which to capture this

information. One approach is to break the migration problem into

reasonable-sized tasks and then compose a task flow, for example, consider

education as a single task. Estimate the effort required and identify the

prerequisite tasks and post conditions that should be met for each task.

A sample collection of project tasks is shown in Table 2-5. The tasks identified in

this sample are for our specific migration effort. Table 2-5 is only a sample task

list. Use it as a skeleton or a template for a your specific Branch Transformation

Toolkit project plan. Your task list will be different, depending on your project and

environment. Set the prerequisites for every task.

Table 2-5 Migration task list

Install

development

environment

Install

test

environment

Remediate

Educate

Prepare

code

Assess Migrate Test Deploy

Check point

Check point

Check point

Task ID

number

Task Prerequisite

task number

Comments

1 Assessment

2 Education 1

3 Install development

environment

2

4 Install deployment

environment

2

5 Code preparation 3