Is Performance Variability Necessary? A Qualitative Study on Cognitive Resilience in Forestry Work

This explored whether performance variability is necessary for tree fallers to safely fell trees. 22 fellers were included in the study.

Whether you buy in to the resilience perspectives or not, or rightly so challenge the state of evidence, it’s still an interesting discussion around the interactions of expertise, context and formal safety systems.

Forestry is said to be often extreme and novel in every situation. Every tree is different (species, health, condition etc), and these factors interact in unknown ways which can result in “often escalating situations” (p2). Unlike many other more stable environments, fallers “deal with complex, dynamic, high-hazard conditions as a regular part of their work” (p2) and is considered normal in this industry.

Many in forestry are said to hold a “traditional” view on safety, where systems are simple, humans subtract safety from the system and therefore introducing constraints which limit their actions and decisions to restrict individual performance variability is preferred; safe work procedures (SWP) are the most common constraint in forestry.

In reality though, people don’t always strictly follow the procedures but is rather “accomplished by intelligently and freely applying the rules based on context” (p3). With this perspective, organisations are seen as complex adaptive entities that are not inherently safe, where people need to anticipate, respond and flexibly respond to suit their context under various conflicting goals.

Performance variability is thus argued to be “necessary and useful” (p3). Building adaptive capacities and foresight is important because “it is only a very brief interval between surprise and success that offers opportunities to discover what one does not know” (p3).

Nevertheless, adaptations result in workers migrating to the boundaries of efficient and functional performance. Most systems are said to have sufficient dampening to ensure this variability doesn’t “combine or escalate in a way that could destabilize the situation. However, once in a while performance variability is not compatible with the conditions and destabilization does occur” (p3).

When the boundary is crossed an incident is more likely to occur. They argue that “incidents are the product of normalized performance that has been produced to counter the effects of other system elements” (p3). Quoting Rasmussen, it’s highlighted that the focus should be less on error and violations but on the “mechanisms generating behaviour in the actual dynamic work context” (p3).

The goal, they argue, should be focused on managing the performance variability so it remains within the boundaries of safe operations rather than trying to necessarily dampen the variability.

Results

Overall, it’s concluded that while safe work procedures provide a good foundation, “it is individual performance variability shaped by experience and ‘‘know-how’’ that guides the application of technical skills in such a complex, dynamic, high-risk environment” (p2), and that “fallers are adaptable and contribute positively to safe and productive systems” (p5).

Fallers consistently explained that possessing and applying technical skills doesn’t mean somebody is competent. Nor will following the rules ensure your safety. Rather, fallers need a strong background to apply the rules and principles in context. Thus, “Applying the rule will improve your odds … but they’ll never guarantee” (p3-4).

Fallers must constantly assess the situation and apply judgement, which is always needed to bridge the discretionary space between technical skills and acceptable performance. Fallers were noted to adopt strategies to make operations successful.

Further, their work showed situational variability, where situations were under-specified and they had to adjust their performance to achieve the best outcome. This was based on assessing cues in the environment, like mentally calculating interactions of forces in motion (trees, branches etc). Importantly, however, “due to the sheer complexity and the unforeseen nature of the environment, conditions often violate their expectations” (p3) and the consequences can be severe.

Notably, “there is seldom a good match between procedures and actual conditions” and while fallers agreed on the value of knowing the fundamentals, the rules “can never fully prescribe what is out there and how best to deal with it” (p4). Quoting Dekker, it’s highlighted that ‘‘rules emerge from practice and experience rather than proceeding them, procedures in other words, end up following work instead of specifying action beforehand’’ (p4).

Fallers each day respond to unpredictable local conditions, hazards and pressures and develop a “license to think” (p4; which I’m not sure is valued enough in the construction industry…supervisors, project engineers and project managers are masters at adapting to local conditions and issues).

Again, fallers agreed that rules are good, but noting that discretion is needed for applying rules and there’s a sliding scale between rules and discretion depending on the context. Procedures are used more as guidelines, where again quoting Dekker ‘‘forcing operational people to [rigidly] stick to the rules can lead to ineffective, unproductive or even unsafe local actions’’ (p4).

Rules are a foundation, or as Guido Carim Jr et al. (2016, Safety Science, 89) noted, “using a procedure doesn’t mean following it”, but rather it acts as a resource for action; amplifiers of human capabilities. So while rules are important, fallers require “options and flexibility”, in conjunction with individual skills and experience, collective know-how, planning + other stuff.

Again quoting Dekker, it’s said that ‘‘Very often working a dynamic environment happens, not in violation of procedures but without procedures all together’’ (p4). Indeed, fallers noted that they still use rules but have learnt to expand them based on their experience in “the safest way you think you can do that” (p.5).

In concluding, it’s said that while many gain comfort in objectively measuring performance, like examination of cuts in tree stumps and auditing work performance, “the empirical evidence contrasted this methodology by stating that, often, focusing too closely on technical skills in the field actually reduces safety” (p5) where “absolute technical accuracy will never guarantee safety in these types of conditions” (p5).

Fallers believed that performance variability is necessary to maintain safety and believed they needed the degrees of freedom and latitude to adapt to conditions rather than being dictated to via rules. They draw on rules as cognitive aids to guide safe practice.

Nevertheless, although actions make sense to people at the time, cognitive limitations of being able to constantly assess such a dynamic and hazardous environment leaves the system open to vulnerability. When fallers’ assessments don’t match the environment, their expectations are violated and failures can occur.

Thus, “while it was agreed that performance variability is necessary and is the reason why things go right most of the time, the same variability is the reason why things sometimes go wrong”.

Link in comments.

Authors: Colman, J. M., Kahle, H. K., & Henriqson, E. (2013). Journal of Human Performance in Extreme Environments, 11(1), 1.