We run forty eight lorries with a crane mounted behind the cab, which is how pallets of blocks and bundles of timber get lifted onto a building site. Every lorry carries a telematics unit that reports its position, its speed and whether the engine is running.
Last year our fleet manager started a fuel saving campaign built on one figure from that data: idle time, meaning minutes with the engine on and the lorry not moving. The crane lorries averaged two hours and ten minutes a day, against twenty five minutes for our vans. The figure went onto a ranking pinned up in each depot's drivers' room, and the twelve drivers at the top were invited to a conversation about leaving engines running.
The first of those conversations ended it. The driver pointed out that his crane is driven by the lorry's engine, through a power take off. When he is lifting twenty pallets onto a site, the engine is running and the lorry is still. That is not idling. It is the job he is paid to do.
We checked, and he was right across the fleet. The power take off has its own signal that the telematics unit could have read, but the units had never been wired to read it, and the idle report had never been asked to leave it out. When we connected it on six lorries for a month, real idle time came to about thirty five minutes a day, close to the vans. The drivers at the top of the ranking were mostly the ones making the most deliveries to sites without a forklift.
We apologised to the twelve drivers in writing, and the ranking came down. All forty eight crane lorries now report crane use, which cost about ninety pounds a vehicle to connect. Idle time is calculated with crane use taken out, and crane use has become a figure of its own, which has turned out to be useful for deciding which sites need a crane lorry at all.
A measurement can only tell apart what its signal can tell apart. Before you publish a figure about people's work, ask someone who does that work what the figure would look like on a day they did it well.
– Serguey Shinder
