Choose a meaningful unit
A smaller tank does not by itself prove better water efficiency. It may simply require more refills. Compare litres used for a defined area at an agreed finish standard, and include water used for servicing the machine. If a route changes its frequency or soil load, record that change before drawing conclusions from the totals.
Look beyond one resource
A cleaning process uses water, electricity, chemicals, consumables and staff time. Savings in one category can come with additional work elsewhere. Measure charging energy where practical and follow the approved chemical dosing and equipment-care instructions. Australian government energy guidance encourages businesses to understand their consumption before identifying improvements; the same measurement discipline is useful when evaluating floor-care equipment.
Report what the trial supports
Set a baseline, use a representative trial and document what was included. Avoid turning a manufacturer’s laboratory claim into a site-wide sustainability promise. If the robot cleaned more often or covered a different area, normalise the comparison before reporting a percentage. The strongest environmental case is a repeatable cleaning result with measured resource use and a maintenance routine that keeps that result consistent over time.