Reviewing and Modifying an IAM Model

You generate an impact analysis model (IAM) by clicking the Generate Model button on the Impact and Lineage Analysis dialog box. An IAM provides a graphical view of your analysis and allows you to save the analysis as a snapshot for later reference.

In the above example, the Employee table shows influencing (lineage) objects on the left and dependent (impacted) objects on the right. Links between the objects represent the analysis rules that propagate actions on objects.

The following types of objects are available in an IAM:

Symbol	Description
	Initial objects - The model objects being analyzed have symbols surrounded by dotted lines. In the Browser, click to expand the initial object to view the tree of its incoming references (impacted objects) and outgoing references (lineage objects). You can also see the list of initial objects by selecting Model > Analysis Objects.
	Impacted and lineage objects - The model objects that are impacted by or influencing the initial objects. In the Browser, these collections of objects are inside folders bearing a downward arrow () for impacted objects or an upward arrow () for lineage objects.
	Link - Analysis rule between initial objects and impacted objects.
[none]	Impacted Models - The models that are impacted by the change. You can see the list of impacted models in the Browser or by selecting Model > Analysis Models.

Note: You can add graphical objects, such as notes or decorative symbols, to your diagram.

You can modify your analysis in the following ways:

To extend the analysis to include objects in the repository, select Tools > Change Analysis Options to open the Impact and Lineage Analysis Options dialog, select Use Repository and specify a Repository analysis level to control the number of levels of dependencies to search for.
To add or remove initial objects to analyze, click Tools > Change Analysis Options, select the Initial Objects tab, and use the Add Objects or Delete tool.
To remove any object or collection and its descendants to simplify the tree, select it in the Browser or diagram and press Delete.
Note: Right-click any node in the Browser or diagram and select Re-analyze to replace any objects or collections that have been removed in this way. To view the available collections and modify those that appear for an object, right-click it and select Change Impact Analysis Objects or Change Lineage Analysis Objects (see Controlling the Display of Object Collections).
To change the action being analyzed for any object, right-click it and select one of Change Action to [Change], Change Action to [Delete], or Change Action Description to open the Action Description dialog (and select one or more of Delete, Change, and any User-defined actions separated by semicolons).
To change the rule set used in the analysis, click Tools > Change Analysis Options to open the Impact and Lineage Analysis Options dialog, select a new rule set and click OK.

IAM Model Properties
The model property sheet displays the definition of the current IAM. You can check the last analysis date of your model or add a comment, for example.
Setting IAM Display Preferences
PowerDesigner display preferences let you customize the format of object symbols and the information that appears on them. To set IAM display preferences, select Tools > Display Preferences, or right-click the diagram background, and select Display Preferences.
Comparing Two IAM Models
Select Tool > Compare Models to view the differences between two IAMs. The comparison window displays the objects contained within the models in a tree format, and highlights the differences between them.

Parent topic: Impact and Lineage Analysis