These are really just two sides of the coin in many ways, with identifiable points in success space coinciding with analogous points in failure space. “Maximum anticipated success” in success space coincides with “minimum anticipated failure” in failure space.
Like everything, how we frame the question helps us find answers. Certain questions require us to think in terms of failure space, others in success. There are advantages in both, but in risk management, the failure space is incredibly valuable.
It is generally easier to attain concurrence on what constitutes failure than it is to agree on what constitutes success. We may desire a house that has great windows, high ceilings, a nice yard. However, the one we buy can have a termite-infested foundation, bad electrical work, and a roof full of leaks. Whether the house is great is a matter of opinion, but we certainly know all it is a failure based on the high repair bills we are going to accrue.
Success tends to be associated with the efficiency of a system, the amount of output, the degree of usefulness. These characteristics are describable by continuous variables which are not easily modeled in terms of simple discrete events, such as “water is not hot” which characterizes the failure space. Failure, in particular, complete failure, is generally easy to define, whereas the event, success, maybe more difficult to tie down
Theoretically the number of ways in which a system can fail and the number of ways in which a system can ·succeed are both infinite, from a practical standpoint there are generally more ways to success than there are to failure. From a practical point of view, the size of the population in the failure space is less than the size of the population in the success space. This leads to risk management focusing on the failure space.
The failure space maps really well to nominal scales for severity, which can be helpful as you build your own scales for risk assessments.
For example, let’s look at an example of a morning commute.