I visited the Norfolk and Suffolk Aviation Museum last weekend.

As you can imagine, there was a lot to look at, from shabby planes and flying machines, smaller and flimsier than I expected, to piles of recovered wreckage, looking extremely sculptural and hundreds of bits and pieces from aircraft and the services that supported them.

It was all a bit overwhelming actually, as I contemplated the people that flew these machines, and why.

But one set of exhibits really struck me. The various ‘computers’ and ‘calculators’ created to enable World War 2 air crews to discover the realities of their situation.

Most of these were made of paper, intricately marked up, and designed so that the user could make an adjustment based on external data and simply read off the result.

The best example was a rangefinder I forgot to take a picture of, used by members of the Observer Corps on the ground.

Imagine two short paper straws, one slightly larger than the other, so it could slide over the other like the outside tube of a telescope.

The outside of the inner straw was marked up with tiny figures. The whole assemblage was used to calculate the distance between where you are and the plane you’re looking at.

All the user had to do was look through the straws at a plane, then slide the outer straw to the point where the plane’s shape just fits into the diameter of the outer straw.

Wherever the back end of that outer straw landed was then translated into distance by looking up the type of plane you were looking at – since if you know what kind of plane it is you have a set of known measurement for triangulation.

What impressed me about this was that whoever had designed this tool, along with the other ‘computers’ around it, had made it with the end-user in mind.

The user didn’t need to do any calculating, just a look-up. All the calculation was built into the design of the tool.

Perfect for a stressful, highly changeable situation where speed counts. Perfect too, for cheap, fast production of these tools at scale.

Of course it does mean that the tool is less general purpose, but it struck me that this kind of approach could be really useful when designing key metrics for your business.

It prompted some questions in my mind:

• What really matters to measure in the moment?
• How can you present your measurement so that the default is to do nothing, because nothing needs to be done?
• How can you take calculation out of the question through the design of your meter?
• How do you calibrate your meter so it can be relied on in real life, stressful, changeable situations?
• How many metrics do you really need to keep your business mission flying well and on course?

Here are a few questions for you too:

• How do you know how well your small business is running day-to-day?
• Could you tell that from afar, or do you have to be there yourself?

Because if you want to be able to take a break, you need meters that other people can use easily.

Upfront Discipline makes Daring possible.