We've been getting a lot of feedback and comments on the Esri data models for the utility network. There's even a discussion here in GeoNet asking questions about missing fields within the UPDM 2018 model.
I can't stress enough that the data models being released by Esri with the utility network (so far Electric, Gas, and Water models have been released) are meant to be starting points and not end all models. We fully expect and encourage business partners and end users to take our models and make changes based on the individual needs of the organization. We've gotten too many reports of users, distributors, and partners thinking they had to follow our data models to the letter and could not change them. This is not the case. The data models Esri puts out are meant to be modified and extended as needed. Feel free to add additional fields, subtypes, rules, etc. based on the needs of your organization. Going forward you will see data models released by our partners that take the original Esri produced models and extend them to meet the more advanced workflows the partner solution addresses.
Another area where you will see partner involvement is with data models that Esri does not plan on providing a starting point for. The core software has the ability to create data models from scratch and partners (as well as some end users) will take this capability to create models for things such as district heating, stream networks, rail, etc.
As you begin to look at, research, and perform proof of concept studies with the utility network, keep in mind that you can and should change the data models to meet your needs.
Esri Product Managemen