Team, My name is Sanket Jayswal from 75F. We are evolving the functionality of our Haystack-based Domain Modeler (tool that supports and comply with Haystack 4 ideology.

I need some information in terms of the use case where equips are modeled more than the Level 1 hierarchy of relationships and are regularly getting used in our Haystack community. Note that I am just looking for equip level hierarchy, i.e. parent equipment and child equipment.

A few examples I got from Protos are:

1. Plant-->Chiller Plant equip-->Pipe Equip
2. Plant-->Boiler Plant equip-->Pipe Equip, etc..

Do we have more use cases other than those mentioned in protos equipment?

It can happen anytime there is an equipment that contains conduits (pipe or duct):

ahu-equip
    discharge-duct-equip
        discharge-fan-equip
             discharge-fan-enable-cmd-point

Although from what I've seen most people tend to flatten the model:

ahu-equip
     discharge-fan-enable-cmd-point

Ducts have dampers/fans. And pipes have valves/pumps which can result in nesting.

Thanks, Brian for the response, do we have some sort of data or understanding on what number (%) of community members are going beyond the level 1 hierarchy and what (%) of members stick to flatten hierarchy?

I always model plants as multi level. Air handlers are based more on their complexity/data points available. For example if an ahu's fan only has command and status points I would leave it flat, but if the fan has a VFD with lots of points I split it out as a sub-equip. I use helper functions in my queries to deal with these variations.

I would suspect a similar approach is used by most in the community.

Thanks, Leroy for your response.

Currently, our tool Haystack Domain Modeler tool does support up to level 1 hierarchy i.e. Parent equip --> Sub-equip.

I am looking for some sort of utilizing data from community members effectively building models with more than Level 1 hierarchy.