Setting asset type to both structure and container

[Jens_Dalsgaard]

Initial note - this is not the Esri electric data model yet the white paper data model as released and documented by Elvia and Volue.

Gain access to this white paper on how to implement utility network for balanced three phase distrib... 

Working with Norwegian DSO, Elvia, and Danish DSO, N1, substations and their interior are documented with great detail. Below is an example of a medium to low voltage substation. In the middle you see two MV/LV transformers. Everything above is medium voltage, and everything below is low voltage. 

Focusing in this context on the medium voltage part, what you see are two medium voltage bus-bars - one with two (three, one idle) line-bays (connected to cables) and a bay connecting to the other, right-hand side bus-bar.

The other, right-hand side bus-bar holds two transformer-bays (connecting to the two transformers respectively. 

Within these bays you see switches, fault indicators, current transformers, etc. - individual features each representing a function in the grid

Whereas in the map each switch, fault indicator, etc. is documented as individual point features, in real world what is here many features may come a one preconfigured unit - we call it a compact-equipment.

Imagine the below subset of the shown substation being one compact equipment that is craned in as one gas-insulated unit. 

To facilitate this we are aiming to document the Compact Equipment unit as a structure junction object in utility network.

This structure junction object asset type is registered as a structure (role type) and corresponding structural attachment rules support relating a compact equipment to all the device features. This all works very fine.

Now, we need to also establish a relationship from the compact equipment to the bus-bar. Yet, according to this Esri documentation structural attachments are not supported against line asset types:

Feature restrictions—ArcGIS Pro | Documentation

Not stopping for anything, we got a new idea. 

• We keep the structural attachment relations to all the devices (point features) as described above
  
  
• And then we add to this containment associations from the compact equipment to the line feature (the bus-bar)

We cannot use containment associations for all relationships to the compact equipment, since point features / devices may only have one containment parent, and the devices are already contained in another container (a substation hierarchy) containment. 
But, that's OK - we can live with using structural attachments to the devices and then handle the bus-bar through a containment association (because line feature do support several containment parents).

SO, we register the compact equipment asset type as container (as well) and add corresponding rules allowing it to contain bus-bar asset types:

Yet, when applying the asset package, we get this error message:

Is it because:

1. We apply the asset package using an oooold ArcGIS Pro (v3.1.4)?
   Will using a newer version of ArcGIS Pro fix this?
   
   
2. An asset type (the compact equipment) cannot be both a structure or a container?
   
   
   
3. we are not smart enough?

We cannot find answers in available documentation.

[MikeMillerGIS · Accepted solution]

2 - An Asset Group/Type can only have one association role.  

Why not make the Electric Device Objects and create a J-J association to the electric point features?

[Jens_Dalsgaard]

Not sure, I understand the suggested approach.

You suggest ? using an electric device asset type to represent compact equipment and then make J-J connectivity associations to all devices and line features being part of the compact equipment?

That would bypass all existing connectivity!

What am I not getting right here?

[RobertKrisher]

Having a feature that is both contained and attached to something provides ambiguity about what the "parent" of that feature is.

The association role of an asset type can be Structure OR Container, not both. In the situation you have outlined I would expect the compact equipment to be a container that contains all the assets, this has the effect of creating a hierarchy of equipment where the devices are in the compact equipment (which I think of as an assembly), and the compact equipment participates in the substation hierarchy.

How the customer thinks about this equipment, and how/whether they model these components in an asset management system will determine which approach to take.

[Jens_Dalsgaard]

We have answers that I needed. Thank you.

Brief comment on my way out. 

All the devices and the bus-bar are already contained in another structure complying to CIM and ERP requirements. It is not possible / desirable to change this.

So, now wanting to also 'group' certain devices and bus-bars in some substations, the challenges are:

• We cannot use containment associations from this new compact equipment asset type since devices may only have one containment parent (makes sense)
• We cannot use structural attachments to this new compact equipment asset type since structural attachments do not work directly against line features. 

I had hoped, we could do a mix 

• Structural attachment associations from the compact equipment to the devices
• AND containment association from the compact equipment to the bus-bar

This is not supported, so we will do with structural attachment associations from the compact equipment to the devices and then either do without any relationship to the bus-bar or simply allow adding the bus-bar GlobalID as a manually entered attribute reference on the compact equipment.

Thank you for the ping-pong.