Understanding substitutes using examples

Let us consider two examples to understand substitutes. Example 1: Consider that Part A is used in Assembly 1. In Assembly 1, Part X and Part Y are set as the substitute parts for Part A, and Part X is the preferred substitute. In such a case, if Part A is unavailable, Part X can be used. If Part X is also unavailable, then Part Y can be used. Example 2: Let us assume that you revise Assembly 1 to create a revision B of the assembly. When you revise an assembly, the occurrences in that assembly are carried forward along with the substitutes. If required, you can change the substitute part. In this example, you can choose to use Part Z as the substitute for Part A instead of Part X and Part Y.