• Resources of type Skill, Tool, and Processing Material are known as Processing Resources.

• A Work Center has the resource type as Work Center.

• A compatibility link cannot exist between processing resources and a work center.

• No compatibility links are allowed on plant and resource groups.

• For any item, it is not possible to set an additional compatibility link to the same item. For example, if for an element A1, a compatibility relationship with element B1 has already been set, it is not possible to create:

◦ one more compatibility link from A1 to B1.

◦ a compatibility link from B1 to A1.