Tool Mentor: Developing a Process Model Using Rational Process Workbench

Tool Mentors > Rational Process Workbench Tool Mentors > Developing a Process Model Using Rational Process Workbench

Purpose

This tool mentor describes how to define new process elements in addition to those elements already defined in the Process Model found in the Rational Unified Process (RUP) and how to derive new process elements from existing RUP elements.

This tool mentor relates to the RUP information:

Overview

Rational Process Workbench (RPW) uses the Rational Rose workspace to develop process models and includes the process model for the RUP.

A common way to customize the RUP is to exclude one or more of its disciplines and to add custom-defined disciplines that will exist in parallel to those disciplines defined in the RUP. Other types of customization occur at more detailed levels, where you modify individual Roles, Activities, and Artifacts to better suit your needs.

Tool Steps

To develop a process model, proceed as follows:

Define new process elements
Derive new process elements from existing elements
Create variation points in your process model
Replace Activities
Replace Workflow Details

1. Define new process elements

Any customization of the RUP you make needs to be maintained in your own process model. When you work inside of your process model, you use the notation supported by the RPW to define new process elements that support your specific process needs.

See Chapter 2, " Modeling elements and principles" in the Developing Process Using Rational Process Workbench manual.

Defining new process elements is a general-purpose, object-oriented, modeling exercise that uses the specific process modeling concepts the RPW has introduced in the Rose workspace.

Refer to the topic titled Defining new process elements in the Rational Process Workbench online Help for detailed information.

2. Derive new process elements from existing elements

If you have the process model from the RUP in your Rose workspace, in parallel to your own process model, you can reuse existing process elements in the context of your customization. For example, you can create a derived role from one of the RUP roles and extend it with additional activities. The resulting derived role assumes the activities of both the RUP role and the new ones. You would want to do this to reuse existing definitions without having to recreate them, as well as being able to use them in their original context. This technique applies when you want to reuse elements within the same process model also.

Refer to the topic titled Deriving new process elements from existing elements in the RPW online Help for detailed information.

3. Create variation points in your process model

RPW supports the use of interfaces to create variation points in your process model. A variation point is a point in your model that can assume any variant of its construct, provided it obeys the contract of the variation point and leaves the remaining model intact. As modeling elements, interfaces provide the specification perspective of such constructs, behind which its variation occurs. Variation points can be formed around the process elements that are modeled using the class construct Roles, Artifacts, Disciplines, and Tools.

Refer to the topic titled Creating variation points in your process model in the RPW online Help for detailed information.

4. Replace Activities

A common customization is to redefine existing activities to use and produce a different set of Artifacts.

The modeling technique used to achieve this is commonly referred to as "operator overloading". In process modeling, this means that a new Activity, with the same name but a different Artifact list, is modeled. The new Activity can then substitute for the existing activity in a process closure.

See the information under the heading "Using operator overloading" found in Chapter 2 of the Developing Process Using Rational Process Workbench manual.

Following our recommendation to separate your process model from the one in the RUP, it becomes necessary to create a new Role on which the replacing Activity can be defined. This is where you use the inheritance construct to associate the new Role with the original one; an association through which the new Role assumes the original Role's other Activities and responsibilities.

Refer to the topic titled Replacing activities in the RPW online Help for detailed information.

5. Replace Workflow Details

Another common customization is to replace existing Workflow Details with new ones that have the same purpose, but different definitions. You use operator overloading to replace Workflow Details in the existing RUP. (See the step 4 for details.)

A replacing Workflow Detail can have a different Activity overview, which employs a different Activity set in a different way. To accommodate your replacing Workflow Detail you need to create a new Discipline on which the new Workflow Detail is created.

Refer to the topic titled Replacing workflow details in the RPW online Help for detailed information.

For More Information

For more information on basic modeling principles, see Chapter 2, Modeling Elements and Principles in the Developing Process Using Rational Process Workbench manual.

Rational Unified Process