Shared object definitions are used to group together similar class definitions that define the same object in different domains. Class definitions that can be shared have a Sharing relationship with shared object definitions.
Shared Object Definition Example
In concurrent engineering, two different authoring tools can create and publish the same object. For example, Aspen Basic Engineering and Smart P&ID can both create and publish the same pump. In Aspen Basic Engineering, a user places a pump called P100 on a PFD and publishes the document. At the front end of the engineering process, very little is known about the pump other than the following:
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Some kind of pumping function is required.
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The pump is connected to streams.
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The streams have a certain fluid code running through them.
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The pump needs to pump at a certain volume.
When the PFD is defined, the user does not know how the pumping function with these general requirements will be accomplished. That information is left up to the P&ID portion of the workflow. In the PFD, the user sees some interfaces and properties of the pump, but not everything that defines the pump in an integrated environment.
In Smart P&ID, engineers start adding value to the design by adding more information, such as the type of pump needed and so on. When Smart P&ID publishes the P&ID containing the same pump (P100) as part of the workflow, the users see more interfaces because the pump object is being enriched as it moves through the design process. When the engineer updates the Equipment Data Sheet in Aspen Basic Engineering, there are thousands of properties describing the same object, further enriching it.
In each authoring tool, the pump (P100) is published with a different class definition, including PFDProcessEquipment, PIDProcessEquipment, and EQDCentrifugalPump. However, a shared object definition called SharedEquipment_PM indicates that these three class definitions all define the same object in an integrated environment. The three class definitions coexist in a sharing relationship. The shared object definition collects information to indicate this sharing relationship.
If you look at the realizes relationship for each class definition, you can see many of the same properties because, as the object moves from one tool to another, properties are updated and the information is enriched.
When an object is created in the PFD, it has a unique identifier for the object (UID). For example, PFD UID AA1 (P100) gets published. Then, Smart P&ID retrieves P100, some additional work is done, and it gets published as PID UID AA2 (P100). The two publishes establish a Same As relationship. The Same As relationship indicates that object AA1 is the same as object AA2.