A School of Continuous Improvement poster finds that 31 per cent of overtime-authorising I'm-here taps sat inside a collect bay, and that Saturday overtime still followed the undifferentiated tap count.
Eighteen grocery stores, 47,216 I'm-here taps, and a roster that counts a kitchen-table tap as a car in the bay
Thirty-one per cent of the taps that authorised Saturday overtime were inside a collect bay. The rest still counted. A research poster published today by the School of Continuous Improvement classifies 47,216 I’m-here taps at eighteen grocery stores, and finds that a supermarket chain’s Saturday labour roster treats a tap from the kitchen table the same way it treats a car in the bay.
The release adds a field taxonomy to the University’s published record of live counts that quietly become the thing they were meant only to report.
A live count will take whatever you feed it, including a tap from the kitchen table, and it will still look like a count of cars.
— Dr Bram Ntuli, Lecturer and Convenor, Improvement Grand Rounds
Origin was coded to four pre-registered classes — collect bay, ring-road, kitchen table, and already in the store — from store-relative distance bands and Wi-Fi network class. Ring-road was the modal class at sixteen of the eighteen stores. Saturday overtime hours follow the undifferentiated tap count and are unassociated with the share of taps that actually sat in a bay. The taxonomy was filed with the chain’s labour panel in January 2026; the roster rule was not revised.
“The taxonomy is now on the labour panel’s file,” said Dr Joost Nwosu, Postdoctoral Fellow in the School of Continuous Improvement. “The roster rule is the same rule it was in March.”
The full poster is available from the University’s research repository under an open licence, doi:10.5555/slop.t6wyye.