Making updates to a component of an application without full knowledge of their effect on the application can cause a large number of unexpected recompilations. Impact assessment is a technique you can use to assess the impacts of updates to an application before they occur. It allows developers to determine what effect changing a given component of the application has on the rest of the application or a given subapplication. Impact assessment enables you to avoid time-consuming recompilations.

Follow the procedure below to use SCLM Build to create an impact assessment:

1. Use the SCLM editor to save the members you want to change
   1. in an empty development group or
   2. save them with a change code.
2. Invoke the build function using the report mode on the top architecture definition for the application affected. If you saved with a change code, create a new top architecture definition that includes the old top architecture definition and uses the CCODE keyword to include the change.
3. Examine the resulting build report. This report reflects all output that regenerates when the build is performed. The build messages data set indicates which translators are invoked.
4. If the results are acceptable, you can proceed with your planned changes. Otherwise delete the members you saved in Step 1 using the SCLM Library utility or the Delete from Group utility.

You can perform a second method of assessing impacts by using an SCLM architecture report. Examine this report for the members that the developer wants to modify. Starting with the members to be modified, you can identify all architecture members that control the modified members. While this technique is more meticulous than the first, it does not require that the member be drawn down, modified, and built.

Either of the preceding techniques help identify costly recompilation impacts.