Weekend ghost flow in an empty building

Background

The factory closes on Friday evening and starts production again on Monday morning. Water continues to pass through the incoming service during the shutdown. Our starting point is the period between those shifts: what does water use look like when the factory is empty?

The problem

The monthly bill combines production demand and weekend consumption in a single total. It gives the team a cost to review, but leaves the timing unexplained. Water running after everyone has left can sit inside that total without drawing attention to the shutdown period. The team needs readings that show when the flow occurs.

How we found it

We use a flow meter on the incoming water service to follow demand through the weekend. Submeters on the largest consumers help narrow the search within the facility. Reading those traces alongside the shutdown schedule makes the remaining flow visible. Overnight and weekend alerts flag demand above the expected baseline, so the team has a specific period to investigate.

What changed

The team can now review a weekend trace and see whether water use falls to the expected zero baseline. An alert draws attention to flow that continues during shutdown. The incoming meter shows the overall demand, while the submeters help direct the next check. That gives the team a clearer starting point for investigating water use before the next monthly bill arrives.

The lesson

We make shutdown periods part of the monitoring plan. For this factory, the weekend provides a clear window for checking whether water is still running after production stops. Keeping that baseline visible gives the facility team a practical check to return to after a change, and an alert when the pattern needs attention again.