When Deviation Becomes the Norm
Beech A100 King Air
A recent crash investigation yielded some very useful insights into why workers deviate from procedures. This analysis applies to any workplace that relies on procedures for safe and reliable outcomes.
Standard operating procedures (SOPs) are a quality assurance tool. In the context of this posting, they define parameters for working safely. Procedures can be perceived to reduce productivity and it seems to be a natural human tendency to deviate from them. Such deviations do not have to be malicious violations (e.g. motivated by laziness or cheating), they can be well-meaning attempts to manage a high workload (including task saturation), to simplify complexity, or to cope with situations not envisaged when the procedures were developed.
With sufficient repetition, deviations can become routine and workers stop recognizing their actions as deviations. The threat of punishment is not a deterrent because these deviations are no longer deliberate (workers don’t decide to risk punishment by deviating, they no longer realize they are deviating). Supervision is the only way to detect deviations and bring them to the attention of workers. Investigating the causes of such deviations can also help improve procedures to reduce the incentive for future deviation.
The accident report explains it extremely well:
“Time and resource pressures can result in individuals making adaptations to get the job done. While SOPs are prescribed in order to set boundaries for safe operations, individuals may experiment with the boundaries in order to become more productive. This leads to adaptations of procedures and a shift beyond the prescribed boundaries described in the SOPs toward unsafe practices.32
“One reason for this is that humans rarely perform work with strict adherence to prescribed rules or instructions. Procedures are often developed for a particular task in isolation from the work context. Performance requirements impose constraints on operators beyond what was considered (and available) when the task instructions were written. To get the job done, people work outside the defined rules. This is why studies of humans, even those working in high-risk, complex systems, have found that operators modify instructions and violate rules in ways that are quite rational given the actual workload and timing constraints (Dekker, 2006).33
“Without regular supervision, education, and enforcement of the expected boundaries, individuals are likely to continue to adapt procedures and cut corners until the actual unsafe boundary is found through the occurrence of a minor or major accident. Additionally, the communication of successful adaptations between crew members … will tend to lead to the spread of these adaptations throughout an organization unless adequate supervision is applied.
“The captain’s history of non-compliance indicates that he had a predisposition toward deviations from required procedures, but does not in itself support a conclusion that the non-compliance was deliberate. The crew of {the accident flight} and most of the other {regional airline’s} pilots were likely unaware that the many policy and procedural deviations identified by this investigation were actually deviations. Some of the SOP deviations were adaptations. As described {above}, adaptations occur when humans adapt their behaviour to their work. … The deviations within the {regional airline’s} operation almost certainly developed into routine practices for the flight crews and were not deliberate digressions.
“Without increased supervisory surveillance to identify routine deviations, crews were unlikely to identify practices that were no longer conforming to established procedure or policy. The new disciplinary policy, designed to stop conscious deviations, was unlikely to have the rapid, broad impact that was intended because it was not accompanied by proactive identification of routine deviations.”*
* Quoted from Transportation Safety Board Aviation Investigation Report Number A07C0001, which listed these references:
32 J. Rasmussen, “Risk management in a dynamic society: a modeling problem,” Safety Science, pages 197, 27 (2-3), 183-213
33 Transport Canada, Safety Study on Risk Profiling the Air Taxi Sector in Canada, September 2007, RDIMS 3820455 v3, paraphrasing from S. Dekker, The Field Guide to Understanding Human Error, Ashgate, 2006
