3 ms·
> "root cause analysis", at least on complex systems, is a fools errand. Not when properly understood--which, to be fair, it often isn't. The proper purpose of
by pdonis 2mo ago
> "root cause analysis", at least on complex systems, is a fools errand.
Not when properly understood--which, to be fair, it often isn't. The proper purpose of root cause analysis is to answer the question: does this failure mean I need to change something about this system? If the answer turns out to be yes, the thing that you need to change gets called the "root cause" of the failure. Of course that's a misnomer, strictly speaking, but that doesn't mean you answered the actual question wrong.
- DrewADesign 2mo agoI don’t blame people for being confused about the term in software — it’s a bit more straightforward in manufacturing, for example. That said, if you look at a system that failed and determine a root cause analysis is pointless, you may have just stumbled upon your root cause.
- marcosdumay 2mo ago> it’s a bit more straightforward in manufacturing That's because manufacturing is a simpler environment where causes and consequences are more conceptually distinct. Until you start to pull management decisions into your analysis, of course. Then it becomes just as complex as software.
- pdonis 2mo ago> Until you start to pull management decisions into your analysis, of course. Meaning, having something like "management will decide not to fund maintenance for this component in the future, causing a failure" in your fault tree?
- marcosdumay 2mo agoYes, and "why did managenent decide not to do it?" too.
- DrewADesign 2mo agoThere’s even more variety in industrial flows than software architectures, and some of them are pretty fucking complex, but the steps are usually better defined, the processes more deliberate, and the custody of material and process oversight is better documented… at least for manufacturers in more advanced countries that are far more liable for product defects. You can dick around with software or software services with relative impunity, but if you release a product with a dangerous manufacturing defect, or lose a few runs of expensive material, the bottom line is not as forgiving. I’m sure there are places in developing countries burning waste plastic to make garbage pot metal products or something for which that level of oversight provides near zero ROI, but outside of that, it’s usually just a lot more deliberate.
- toolslive 2mo agomaybe, it's the other way around: If you search for one, and you find one, then your system is not complex.
- onion2k 2mo agodoes this failure mean I need to change something about this system? It's safer to say 'does this failure mean I need to change the system?'. Otherwise you're still facing the single cause trap.
- pdonis 2mo ago> Otherwise you're still facing the single cause trap. "Something" does not have to mean "one single thing". But I would be fine with your phraseology if it ended up making it clearer to whoever was doing the analysis.
- tptacek 2mo agoCook doesn't object to postmortems and to using hard failures as opportunities to spot interventions (though, remember, all practitioner actions are gambles). The issue is in attempting to identify a single privileged root cause.