Decision Making / 2 / 2.2 / 2.2.5

2.2.5 A Call For Quantification Of Causal Linkages

Unfortunately for the sake of this research, the Board did not assign weightings to causal links. In his report to the Minister for Defence, the Chief of Army commented on those 16 directly causative factors and the 26 contributory factors as follows:

‘The linkages established by the Board are reasoned and reasonable, but are also contentious in the sense that the weighting given to each factor is not clearly established in the Report and therefore, the paths which lead to the inevitability of this accident are likely to be the subject of some controversy, particularly where they are alleged to include issues of individual neglect.’ (LTGEN J.M. Sanderson, CA 102/97 dated 22 Feb 97, as quoted in Australian Army, 1996).

In reporting to Chief of Army, the legal adviser to the Board of Inquiry made the following observations (Australian Army, 1996):

‘13. The BOI did not attribute the accident to a “single catastrophic event”. Rather, it identified some 16 causes and 26 contributory factors. The BOI offers no criteria which led it to place matters in one category rather than the other. It is difficult to discern the basis upon which the distinction is based. For example, it is not immediately obvious why “probable misidentification of a target due to an incorrect mental model of the objective on the part of the flight lead” is considered a primary cause of the accident when “an objective which proved exceedingly difficult to identify in the prevailing light conditions under [Night Vision Goggles] NVG” is found to be merely a contributory factor.

Similarly, there is no apparent reason for identifying “inadequate planning for the air mission on 12 Jun 96” as a primary cause of the accident and “inadequate combined planning for the airmobile mission on 12 Jun 96” as a contributory factor.

14. In identifying the primary causes of the accident the BOI did not seek to suggest any particular order of significance. This is unfortunate. Nonetheless, it is clear that the immediate cause of the accident, as found by the BOI, was Black 1 turning right, converging on Black 2 and coming into collision with it. Black 1’s main rotor blades came into contact with the tail and fuselage of Black 2. There were five strikes. The main rotor blades of Black 1 were severed and it plummeted to the ground. The tail rotor section of Black 2 was severed and it crashed some 5 to 10 seconds later. These events, in my opinion, constitute the primary causes of the accident. The other factors which are so characterised in the report (with the possible exception of the finding that the helicopters were flying off track in their approach and did not adopt a heading which would re-intercept the track, thereby significantly changing the final approach track to the objective compared with the rehearsed approach) should, in my view be considered as contributory factors.’

There is a growing interest in the quantification of concept maps, causal-loop and influence diagrams. A number of authors have suggested a need for adding weightings, or some form of quantification, to each link to indicate the magnitude of influence one concept has on other connected concepts. Comments, above, by the legal adviser to the Board of Inquiry clearly indicates he would like to see such analysis.

In his PhD research, the author found highly valuable and robust results flow from the use of qualitative analysis alone. Coyle (1999, 2000) expresses a similar view, noting that the effectiveness of qualitative analysis depends on how comprehensive is the understanding managers and decision makers of the ways complex systems operate. That is, managers and decision makers need to be highly competent systems thinkers. The case studies presented in this book provide a sound foundation for managers to build the necessary systems thinking skills. However, frequently the only way to build the necessary understanding of specific dynamic, systemic, complex problems is through quantitative (computational) system dynamics modelling. This is addressed again at Chapter 4.