IBM SG24-7368-00 manual Level 0 model organization, Project

On balance, we find that flip charts are often the best way to begin a modeling effort and to do the initial drafting of model elements, use case flows, and diagrams. When the model has reached some level of stability, we find it best to put the model into a UML or SysML modeling tool, such as Rational Software Modeler, Rational System Developer, or similar, and maintain it there.

In other situations, where the engineers involved are experienced in using modeling languages and modeling tools, it might be better to proceed directly to using the modeling tool to capture the modeling work right from the start.

Organizing an MDSD model using tree-structured packages in a modeling tool can be confusing. The following sections detail an approach that we have found to work.

Level 0 model organization

In Figure 6-1we show the main enterprise modeling elements. Blue boxes represent packages and yellow represent diagrams. The locations of individual modeling elements are shown in the next sections. At the top, a single Level 0 package contains the context and use case diagrams for the enterprise. Below that, a package is created to contain all of the use cases at this level. Within this package, a package for each use case contains the optional activity diagram for this use case, as well as the black box sequence diagrams for all documented scenarios of this use case.

Project

Level 0

Context Diagram	Use Case
	Diagram
Use Cases

L0 Use Case “A”

Activity Diagram

Sequence Diagram

(Black Box)

At Level 0, only use cases appear in the model; Level 0 operations will appear in their realization in Level 1.

L0 Use Case “B”

Figure 6-1 Level 0 model organization

Chapter 6. Tool support for MDSD 95