Complex systems present as “wicked problems”. They are dynamic, unbounded, incomplete, contradictory and constantly changing. They comprise an indefinite set of subcomponents that interact with each other and the environment in unexpected, non-linear ways. They are thus unpredictable, chaotic and “insoluble” — no algorithm can predict how they will behave in all circumstances. Probabilistic models may work passably well most of the time, but the times where statistical models fail may be exactly the times you really wish they didn’t, as Long Term Capital Management would tell you. Complex systems may comprise many other simple, complicated and indeed complex systems, but their interaction with each other will be a whole other thing. So while you may manage the simple and complicated sub-systems effectively with algorithms, checklists, and playbooks — and may manage tthe system on normal times, you remain at risk to “tail events” in abnormal circumstances. You cannot eliminate this risk: accidents in complex systems are inevitable — hence “normal”, in Charles Perrow’s argot. However well you manage a complex system it remains innately unpredictable.

In which the curmudgeonly old sod puts the world to rights.
Index — Click ᐅ to expand:
Tell me more
Sign up for our newsletter — or just get in touch: for ½ a weekly 🍺 you get to consult JC. Ask about it here.


You can’t eliminate the risk, so focus on managing it

A traditional risk manager will be conditioned to using control techniques to anticipate and eliminate all risk. In a complex system this is simply not possible. One must instead depend on local managers and experts making spontaneous decisions to address the unfortunate situation as they see it and under conditions of significant uncertainty. A complex system is not totally random — in that case any action would be as good as any other — so some control is possible, but it is not possible to prescribe in advance what that action should be.

Frequently complicated system risk attenuators can, in fact, aggravate risk situations in complex systems. Alarms going off make it harder to hear; multiple alarms increase panic and obscure each other; an obligation to follow prescribed safety routines can impede quick and surgical response to traumatic situations. There are times, therefore, where you want to throw your checklist out the window. [1]

  1. I know, I know — try telling that to the chap who landed his plane on the Hudson thanks to his unflappable compliance with cockpit checklists, right?