There are four tabs on the Parts screen where the purpose is to associate one or more parts to the selected record view part. The Substitutes tab is one such tab. Part conditions is implemented differently here because it could get confusing to first select a substitute part (including condition), then select the condition, or child part, for which it should be associated if a parent part were selected on the record view. Condition tracked child parts can be substitutes for other condition tracked child parts and vice versa.
The Substitutes tab will be protected if a parent part is selected on the record view. To associate a substitute part to a condition tracked child part you will first need to select the appropriate child part on the record view. Clicking the Substitutes tab reveals a protected Condition field. If a parent part is selected on the tab the Condition field becomes required and will contain the conditions for the template associated to the parent part. The Condition will then be chosen. Because the Condition is really a child part the system will update the parent part to be the child part code related to the Condition. This child part is what will be saved as the substitute part. Selecting a parent part (i.e., this is likely the part # everyone is familiar with) forces a Condition to be chosen. Once the Condition is chosen the substitute part becomes the part associated to the Condition.
The child parts are also displayed in the Part lookup so if the user knows the child part number, they can easily select it. If a child part is selected the system will populate the Condition from the child part.
A condition will not be displayed in the Condition lookup value if it is associated to the record view part. If the record view part is a New condition part, you cannot select the same part as a substitute.
The implementation of the part condition enhancement on the following screens is like the Substitutes tab: