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(re safety differently ADQ4.a)

(published 12/3/17).



4. At paragraph four, page. 22., it says safety differently wants “to move beyond the sector’s default setting of linear thinking and analysis of cause and effect”.



a). Does the sector have such default settings?

b). What alternative way of “thinking” about cause and effect is John Green and safety differently advocating?



The response here is in two parts.


Part 1.

The approach since the late 1960s has been increasingly multi-factoral and systemic and is supported by writers such as Gordon, Adams, Weaver, Bird, Petersen, Turner, Perrow, Reason, Turner & Pidgeon, Dekker, Hollnagel and, for instance, the UK Health & Safety Executive. Indeed, Reason, Hollnagel & Paries (2006) have said the “understanding of how accidents occur has during the last eighty years or so undergone a rather dramatic development. The initial view of accidents as the natural culmination of a series of events or circumstances, which invariably occur in a fixed and logical order (Heinrich, 1931), has in stages been replaced by a systemic view”.

The following is from a Phd thesis (Arnold 2009) supervised by Professor Dekker himself and may further assist. At p.13, the thesis offers this...


“Around the turn of the century many leading human factors leading researchers (Woods and Cook (2002), Leveson (2004), Cook and O’Connor (2004), Hollnagel 2004 and Dekker (2006 b), Richard Cook (2004)) began calling for new models to better explain failures in increasingly complex systems...Clearly, a model that accommodates these characteristics must be fundamentally different to the prevailing epidemiological model with its linear pathway, active failures and latent conditions”.


The epidemiological model is, of course, attributable to Gordon (1949) (i.e. the first author cited in the opening paragraph above) whilst the active failures and latent conditions are Reason (1990). Furthermore, the thesis, supervised by Dekker, makes no reference whatsoever to either Bird, triangles, dominos or Heinrich.

Interim Comment (1):

Since the article has emphasised this aspect twice, Part 1. should be read in conjunction with Part 1. of ADQ5.d. here.  



Part 2.

Terms like “simple linear models”, “linear logic” and “simple linear thinking” (Hollnagel & Wears 2015) tend to appear amidst academic appeals for “non-linearity over linearity”, “complexity over simplification” and “holism over reductionism” (Dekker et al 2008). As such, the call to reject cause and effect in the context of the article is an appeal to emergence.  


Interim Comment (2):

The claim of emergence pre-supposes investigative rigour. However, basic (yet potentially far reaching) mistakes were made in respect of a ‘triangle‘. Consequently, some may ask if the other criticised aspect of Heinrich was better understood and applied ahead of surrender to emergence. Such a question would not be flippant. Engineers and scientists working on safety problems know “the reductionist attitude provides a useful filter that saves scientists in all fields from wasting their time on ideas not worth pursuing” (Weinberg 1992). Indeed, some may well be enquiring as to the whereabouts of Ockham’s Razor.



The Institute of Industrial Accident Investigators. All rights reserved.