In February 2016, Daniel “Mirf” Montes published his doctoral dissertation, “Using STPA to Inform Developmental Product Testing.” In it, he explains that STPA is “an engineering approach that identifies explicit causal scenarios for accidents.” In particular: “I developed a method to extend STPA called STPA-RC, where ‘RC’ means refined controller-analysis… Incorporating human behavior into STAMP and STPA has taken several forms in previous research, and STPA-RC aims to capture the important attributes of those efforts and address the existing research gaps to produce an updated analysis technique for intelligent controllers.”
The ideas are noteworthy, and we ought to examine them and discuss them thoroughly. They rely heavily on control theory. He has since worked with the Air Force on field tests of the STPA, the subject of a future newsletter. One of the features I really like is the methodical way he identifies hazards using the control theory framework, rather than trusting the (possibly disorganized) brainstorming ability of the test team.
Objections
I heard his talk in 2017 at the SFTE National Symposium in Destin, and it left me with three major questions. I’ve since read his dissertation in search of answers to these questions and have yet to resolve them. We should discuss these as well.
1. Does this systems theory approach adequately address complexity?
2. Does it adequately address the objections raised by proponents of design thinking as a replacement for systems thinking?
3. How do we address the tension between heuristics and the organized methods of the systems process? On the one hand Beaker argues for heuristics as a necessity to address complexity, but we can all agree that heuristic approaches to brainstorming hazards may not be adequate. On the other hand, the method is very structured and rigid, and specification of the system design may not allow cognitive margin for helpful application of both heuristic and creative problem solving that uniquely defines human thinking.
Slides: Safety Planning Using Applied Systems Theory
Dissertation: Using STPA to Inform Developmental Product Testing