I have implemented the Water Distribution Utility Network Solution. The system and pressure subnetworks defined in this model use the Lifecycle Status (Does not include In Service and To Be Retired) as a condition barrier. This has caused some issues creating subnetworks with approved to be constructed features and valves that are abandoned in the open position. These features prevent subnetworks from being created correctly by stopping the subnetwork from continuing past devices with those Lifecycle Status values. It is fairly common in our water system that valves, tees, and other junctions are wet tapped into existing waterlines.
I'm considering adding a new true/false attribute to the feature classes and the network called "traceable". Generally this would be true for Lifecycle Status In Service and false for Approved, Abandoned, Removed. Then for junctions or devices that connect to in service lines set the traceable to true (the circled features in the image). Then I would remove the Lifecycle Status condition barrier and use the traceable value as the condition barrier. The obvious drawback of this is the some approved features will be included in subnetwork traces before they are installed. Are there other unintended consequences that I'm not considering?

@MikeMillerGIS @RobertKrisher @JoelSmith3