When a handheld scanner stops working at one of our depots, the supervisor boxes it up, a courier brings it to head office, and a spare goes back the other way. Our repair bench handles about ninety devices a month. The figure we reported was turnaround, and it was good, usually under two days.
In February the spare pool ran dry for the first time, in a week when nothing unusual seemed to be happening, so I asked the bench engineer what he was actually finding. He had been writing it down all along, in a notebook, because the ticket had no field for it. Thirty one percent of the devices sent to him last year had no fault he could reproduce.
Where they came from was the interesting part. Almost half of the no fault returns came from four depots. At two of them the charging cradles had worn or dirty contacts, so a scanner left in overnight started the shift nearly flat and died by mid morning. At the third, an access point had been replaced with a model the scanners took twenty seconds to roam onto, and staff sent back devices that froze in one aisle. The fourth had a supervisor who had learned that sending a device away was quicker than restarting it, because nobody had ever shown her how.
Each of those devices cost a courier both ways, an hour of bench time and a day without a scanner, and left the actual cause at the site, ready to produce the next return.
The ticket now asks for the symptom, and the bench records what it found against the site as well as the device. Any site with three no fault returns in a month gets a call from the bench engineer before it gets another spare. Cradles are cleaned and checked on the same visits as the label printers, and forty of them have been replaced. A card taped inside every cradle cabinet shows the restart and a two minute check.
No fault returns are down to about one in ten, and the spare pool has not run out since.
A single device on the bench told us almost nothing. Devices arriving from the same place told us most of what we needed to know, and that pattern had been kept in a notebook.
– Serguey Shinder
