In 1986, millions of people witnessed the Challenger space-shuttle explosion that tragically killed seven astronauts, including a civilian teacher on board for the Teacher in Space initiative. Investigations revealed the explosion was caused by the failure of a large O-ring designed to seal a fuselage joint in the rocket booster. The Presidential Rogers Commission attributed the disastrous event directly to decisions made by NASA managers to proceed with the launch, despite apprehensions around the O-ring performance and weather conditions the morning of the launch.

In the 10 years following the tragedy, sociologist Diane Vaughan committed herself to understanding what happened at a deeper level, delving into the complex historical and organizational context at NASA. She suggested in her book, “The Challenger Launch Decision,” an alternate explanation to that determined by the Rogers Commission. Rather than attributing fault for the tragedy solely to the managers who made dubious decisions regarding launch safety, Vaughan found that shuttle launch operations involved a great deal of uncertainty around risk levels. This led Vaughan to develop the concept of normalization of deviance, the gradual slip toward unsafe behaviors, practices and risk acceptance that set the stage for the Challenger explosion.

So, what does this have to do with tree work? Probably more than you would guess.

Tree care and risk
It is no secret that the tree care industry experiences significantly more than its share of serious mishaps, and that the risks undertaken by those engaged in tree care work are notable.

• Work at height? Check.
• Anchor points and dynamic rigging forces in non-engineered structures? Check.
• Large, powered equipment? Check.
• Structurally compromised trees? Check.
• Proximity to energized conductors? Check.

The list of hazards stretches on, and our routine interactions with those hazards create significant risk factors. And much like the challenges facing NASA engineers, we often operate under “better, faster, cheaper” pressure while navigating high-risk work.

Rather than respond to mishaps or close calls in tree care operations by pointing the finger and attributing blame, as was the case with the Challenger explosion, there is much more we can learn by seeking to understand the nuanced context and network of influences that create the conditions wherein we interact with these hazards.

Think in terms of risk
If you were to ask a room full of people to write down their definition of safety, many will share similar ideas and themes, but each will be different. The term “safety” contains many meanings. It can be helpful to think of tree care operations in terms of risk. Put simply, risk is the likelihood of a harmful outcome combined with the potential severity of the harmful outcome. Instead of viewing a tree care operation or work task as either “safe” or “unsafe,” describing tree work using risk language provides nuance and allows us to more accurately describe the nature of our work.

Risk also can account for exposure levels, experience, personal perceptions and tolerance, as well as the ways we balance risks and with what expected benefits. In the case of the Challenger explosion, with each successful launch, the concerns about O-ring performance were perceived as less important, and the launch team normalized the risks they had identified earlier in the shuttle engineering process.

So, where does this take place in tree care? One area that arborist climbers navigate daily is primary-suspension-point (PSP) selection. In terms of risk, the consequence of a PSP failure is catastrophic (death or serious injury, in many cases), while the likelihood of a PSP failure is more ambiguous.

How do we know if a PSP will withstand the forces the climber will place on it? The answer is dependent on contextual factors such as tree species, condition of the tree, structure of the branch union, placement of PSP within the branch structure and climbing system or technique being used, among other considerations. Even when each factor is addressed to minimize risk levels, the climber must make a decision: either accept the final risk level (including any lingering ambiguity about PSP strength) and proceed with the climb, or abandon the effort for an alternate plan.

And PSP selection is only one initial decision among a host of others the climber must navigate. Real-world tree care work requires balancing countless factors and influences. Everything that occurs in tree care operations is dynamic and interdependent. Much like NASA’s informal motto in the ’80s, “better, faster, cheaper,” consider the complex balancing act that tree crews undertake: production, efficiency, safety.

Factors that influence operations
It is important to recognize the diverse factors that influence how tree care workers navigate a dynamic environment to conduct their operations.

Operational pressures: Clients, managers, teammates, neighbors, members of the public and internal motivations all influence the pressures experienced while conducting tree work. Work specifications and allocated time create additional pressure.

Efficiency: Tree work is difficult and strenuous. Tree care workers aim to be as efficient as possible, both in physical exertion and in the scope of work they are tasked with completing.

Conflicting goals: Crews consistently navigate goals that conflict with other goals. For instance, a client may be extremely concerned that operations not damage their lawn, while the climber is concerned that the tree may not be structurally able to withstand the rigging forces required to rig everything to the ground.

Limited resources: Crews routinely undertake work with limited resources such as time, equipment, people, experience, etc.
Uncertainty: Certainty only comes through the benefit of hindsight. Every crew operates from their perceptions of what they believe the outcomes will be, but no crew can predict with absolute certainty what will result from a course of action. (See Work as Done graphic)

Local rationale: People will act in the way that makes sense to them, given their understanding of the situation in that moment. Each of the factors above influence the local rationale for tree care workers. Local rationale considers the question, “Why did it make sense for the person to act in the way they did?” (Sydney Dekker and Todd Conklin)

Plan-Do-Check-Act
This provides a starting point for us to increase our awareness of the complex system we all operate in as we seek to complete our work. This awareness affords the ability to see some of the shifting as it happens and be able to adjust, balancing the system.

We can improve our capacity to manage this balancing act by building systems for the different types of work we do, allowing our focus to stay on the most critical tasks we need to balance, because we know how the rest of the systems will function. Specifically, we can build safety management systems (SMS) into our operations through a Plan-Do-Check-Act continuous-improvement cycle.

First, we Plan for how our work is going to happen with policy, procedures and safe work practices.

We then Do the work using everything we set out in our planning phase, making small adjustments as we manage our complex environment.

Next, we Check the performance of the work, reflecting on how work actually occurred and where it deviated from our expectations and plans, to understand where we can learn and improve.

Finally, we Act on what we learned from the reflection on our work. At this stage, we make the adjustments necessary to improve safety, efficiency and resilience against potential hazards that must be managed. (See Plan-Do-Check-Act graphic)

As we go through the Check and Act phases, the importance of the last two phases cannot be emphasized enough. If we only plan for and do the work, we will miss the important feedback that will help us navigate out of the risk we might be operating in, because we will not have recognized why we had the outcome that happened or ways we can adjust our systems to create desired outcomes in the future.

Encourage feedback
An important part of getting the right feedback as we check our work is ensuring the crew members feel safe to share their thoughts and opinions. Leaders must create a psychologically safe environment where honest feelings and opinions can be shared amongst stakeholders, so everyone can contribute to finding the best path forward. Leaders should recognize that workers have important insight and solutions to many of the problems they face, but they need to feel comfortable sharing them or we inhibit everyone’s capacity to learn and improve.

We are not alone
Those of us within the tree care industry are not the only ones concerned with addressing the risks of serious incidents and fatalities (SIFs). There is an ever-growing academic and professional interest in occupational safety that has led to exciting paradigm shifts in how we understand safety. Sparked by the work of researchers in the ’80s and ’90s, Eric Hollnagel, Sydney Dekker, Todd Conklin and others have helped us to look at safety differently.

Rather than responding to accidents by pointing the finger or understanding safety as a simple matter of personal responsibility, this new take on safety seeks to understand how the dynamics of complex work interact to influence how real-world work, such as tree care operations, takes place. By shifting our perspective to try to understand the systems view, we can more effectively influence the environment in which work takes place, making for better avenues for tree care workers to navigate the risks inherent to their work.

Tyler Lyon, CTSP, ASP, is a regional safety manager for Bartlett Tree Experts in the Pacific Northwest, operating in the U.S. and Canada.

Chris Sprague, MEng, CTSP, ASP, is a regional safety manager in the Mid-Atlantic and New York areas for Bartlett Tree Experts, an accredited, 51-year TCIA member company headquartered in Stamford, Connecticut.

This article is based on their presentation on the same subject during TCI EXPO ’24 in Baltimore, Maryland.

Sources
Plan-Do-Check-Act image: “The Learning Enterprise Innovative Practices for Organizational Transformation,” by Arthur Poh et al, 2020/11/13; SN 978-981-14-6455-3.