Understand entities with multiple parents

In the entity tree, entities can have multiple parents under the following conditions:

• The entity’s tree branch includes ancestors; that is, the child’s immediate parent and any other parent entities higher up in the same branch of the hierarchy.

• The entity has been copied to one or more parents in addition to the parent under which it was originally created.

Copying an entity to another parent is different than cloning the entity. Copying the entity does not create a new entity. It is the method used to assign an additional parent to the entity to either better model the plant entity structure, to make it easier to identify similar entities, or so that the new parent’s associations can be inherited. Cloning an entity creates a completely new entity with the same properties as the source entity.

The ability to copy entities to other parent entities allows entities to be grouped by common attributes for operational purposes. For example, say you have a machine shop with a number of lathes that are located in three distinct areas of a shop floor. To model the physical layout in the MES Client entity tree, an entity is created for each shop floor area and the lathe entities are created under the shop floor area entity in which they are located. However, you also want to group lathes by length, throw, or horsepower so that jobs that require a certain value for one of these attributes can be run on any of the lathes that meet that requirement, regardless of its location. In this case, you would create parent entities for each classification of attributes that is required and then copy the lathe entities to the parent entities whose requirements they meet.

Note that entity classes or standard entities can be used to provide this grouping functionality.