The figure nobody measures and everybody argues about

There is a scene that repeats itself in plants from sectors with nothing in common. The monthly operations meeting starts, the yield figure appears, and the first forty minutes go on establishing whether that figure is real. Production calculates it one way, maintenance another, and the management system has a third version.

By the time everyone agrees on the number, there is little time left for the only thing that mattered: deciding what to do about it.

The problem is almost never missing sensors

In the diagnostics we run, the commonest finding is not that instrumentation is missing. It is that what exists has never been reconciled: two meters in series that disagree, a totaliser that resets on every power cut, one production figure captured by hand at the end of the shift and another coming out of the PLC.

Adding a third meter to that situation solves nothing. It produces a third figure to argue about.

Three things that do solve it

• A declared source for each indicator: which instrument, which calculation, which frequency. Written down and visible on the same dashboard the number appears on.
• Automatic reconciliation between redundant measurements, with the discrepancy shown rather than hidden.
• Traceability backwards: being able to open any figure in the monthly report down to the reading it came from.

The side effect

In the projects where this was fixed first, the immediate benefit was not a gain in yield. It was that the meetings changed subject. Once the figure stops being disputed, the conversation moves to the cause, and the cause is the only thing anybody can act on.

Instrumenting properly does not generate new information. It ends an old argument, which is worth more.

It is also the cheapest part of any digitisation programme, and the one most often skipped because it does not show up in a demo.