Managing Model Objects › Model Object Audit Information › Determining the Change Type

Determining the Change Type

The change type describes the way in which a change to a model object affects other objects that use the changed object. Its purpose is to retain the integrity or functionality of both model objects and implementation objects. It is used primarily during component change processing, a process that ensures that the effect of a change is distributed throughout the model.

CA 2E determines the change type using a shipped table that assigns a change type to each position on a CA 2E panel where you can possibly change a model object.

For more information:

• On component change processing, see the Impact Analysis section in this chapter.
• On the shipped table of change types, see the appendix titled "Change Control Facilities Reference Tables" in this guide.

Following is a list of change types and their definitions. Only private and public changes invoke component change processing.

• Object Only (*OBJONLY)—A change that affects only the model object and does not require regeneration. The change has no effect on model objects that use the changed object.
• Generation Required (*GEN)—A change that affects only the model object and requires that the changed object be regenerated to effect the change in its implementation object. This change type is used only for access paths and external functions. The change has no effect on model objects that use the changed object.
• Private (*PRIVATE)—A change to an object that requires regeneration of the external functions and access paths that use it to effect the change in the implementation objects.

  For example, if you change a file on the Edit Database Relations panel, you need to regenerate all external functions and access paths that use the file. Or, if you change the action diagram of an internal function, you need to regenerate all external functions that call it.

• Public (*PUBLIC)—A change to a model object that changes its interface with the model objects that use it. This change also requires the following additional processing:
  1. Model objects that use it may need to be edited.
  2. External functions and access paths that use it need to be regenerated.

  For example, if you change the parameters of an internal function, you need to edit all functions that call the changed function and then regenerate all external functions that contain it.

The four change type values just presented were listed in order of increasing significance:

1. Object Only
2. Generation Required
3. Private
4. Public

In other words, if you make multiple changes to an object, a higher-numbered change overrides a lower-numbered change, and not vice versa. For example, a public change overrides a private change, but a generation required change does not.