Managing Capacity, Not Uncertainty
Safety isn’t the absence of accidents; it is the presence of capacity. We don’t make our systems more reliable by taking the negative out, we do it by putting positive things into the system. Those positives are the capacity.
We are really good at managing capacity without giving it a thought. The fuel gauge in your car measures capacity. If I have to drive 30 miles, but only have 20 miles of gas left until I am empty I know I need to stop and get gas. Some people might try and beat the gauge, but this increases risk and will lead to an unwanted outcome. We are able to manage capacity because it is known.
FedEx has improved their process of moving packages by increasing their capacity. Each night, FedEx has two, 767 cargo planes leaving Denver to Memphis. One plane flies two hours direct, loaded with packages. The second, empty plane flies four hours from Denver, west to California, south towards Mexico and finally east towards Memphis. Why does FedEx make a plane fly a two hour trip in four hours and empty? The second plane flies in the event the first plane needs assistance, or if there are more packages. In fact, this second plane is a big investment that is needed 75% of the time.
You can’t predict when it will be needed, so the second plane flies every time, which has increased capacity to ensure a successful mission. This is a good example of making sure what you want to happen, actually happens.
We can’t plan for an unplanned event because we don’t know what we don’t know. We build capacity into the system to increase our ability to recover and continue on. FedEx didn’t one day decide that they are going to fly an additional 767 in each of their four operating quadrants each night. They came to this by learning. Think of it as a series of tweaks to improve the process as a whole and make it more robust and reliable. Sometimes the tweaks even need to be tweaked, but the focus is on continual improvement.
Do you have the capacity in your systems to recover and continue when the unplanned happens?