Measurement can impair foresight

It is easy to set-up measurements, but also to get ensnared by them; this is the warning of the McNamara fallacy. The phrase does no favours to Robert McNamara, whose use of measurements to direct the Vietnam War have become notorious. But, it’s not about one man’s standing; the fallacy offers an insight into how organisations work. It describes a trap that is easy to fall into. At the start of a project or policy launch, it’s usual to get things on track with some rough and ready measurements. Our firms give measurements clout, while obscuring their origins. This makes them hard to challenge or revise. Once set up, approved measurements can dictate our thinking. They can make other ways of looking at things irrelevant, invalid, hard-to-discuss or even invisible. And this is true not only of the numbers, but also the ideas and viewpoints that underlie them. Unfortunately, because we are pretty good at explaining away accidents and troubles, the status-quo can become self-sealing. In his statement of the fallacy, Dan Yankelovich described this loss of foresight as blindness. In safety, a prime example is the managerial fixation on measuring lost time accidents at BP’s Texas City refinery. Investigators found that this obscured serious process safety problems and helped to create a catastrophe. Tools easily become masters, especially when employees lack insight into their principles or find it hard to challenge their use. Tragedies like Texas City are exceptions, but losing foresight through the McNamara fallacy may be common.