The human element - errors and violations
Over the past two decades there has been a growing appreciation of the many and varied ways that people contribute to accidents in hazardous industries or simply in every day life. Not long ago most of these would have been lumped together under the catch-all label 'human error'. Nowadays it is apparent that this term covers a wide variety of unsafe behaviours.
Most people would agree with the old adage 'to err is human'. Most too would agree that human beings are frequent violators of the 'rules' whatever they might be. But violations are not all that bad - they got us out of the caves!
One of the most important distinctions between errors and violations is that each has different mental origins, occur at different levels of the organisation, require different counter-measures and have different consequences. Everyone in an organisation, from members of the Board to those at the coal-face, bears some responsibility for the commission of violations. It also follows that all employees have a part to play in minimising their occurrence.
Assuming that a safe operating procedure is well-founded, any deviation will bring the violator into an area of increased risk and danger. The violation itself may not be damaging but the act of violating takes the violator into regions in which subsequent errors are much more likely to have bad outcomes. This relationship can be summarised:
Violations + errors = injury, death and damage
It can sometimes be made much worse because persistent rule violators often assume, somewhat misguidedly, that nobody else will violate the rules, at least not at the same time! Violating safe working procedures is not just a question of recklessness or carelessness by those at the coal-face. Factors leading to deliberate non-compliance extend well beyond the psychology of the individual in direct contact with working hazards. They include such organisational issues (latent failures) as:
- The nature of the workplace
- The nature of the workplace
- The quality of tools and equipment
- Whether or not supervisors or managers turn a 'blind eye' in order to get the job done
- The quality of the rules, regulations and procedures
- The organisation's overall safety culture, or lack of.
Violations are usually deliberate, but can also be unintended or even unknowing. They can also be mistaken in the sense that deliberate violations may bring about consequences other than those intended, as at Chernobyl. In this case, out of the seven unsafe acts (active failures) leading up to the explosion, six were a combination of a rule violation and an error (a misventure). Here was a sad and remarkable case in which a group of well-motivated and exceedingly expert operators destroyed an elderly but relatively well-defended reactor without the assistance of any technical failures.
| Errors | Violations |
| Stem mainly from informational factors: incorrect or incomplete knowledge, either in the head or in the world. | Stem mainly from motivational factors. Shaped by attitudes, beliefs, social norms and organisational culture. |
| They are unintended and may be due to a memory failure (a 'lapse') or an attentional failure (a 'slip'). | They usually involve intended or deliberate deviations from the rules, regulations and safe operating procedures. |
| They can be explained by reference to how individuals handle information. | They can only be understood in a social context. |
| The likelihood of mistakes occurring can be reduced by improving the relevant information: training, roadside signs, the driver-vehicle interface, etc. | Violations can only be reduced by changing attitudes, beliefs, social norms and organisational cultures that tacitly condone non-compliance (culture of evasion). |
| Errors can occur in any situation. They need not of themselves incur risk. | Violations, by definition, bring their perpetrators into areas of increased risk i.e. they end up nearer the 'edge'. |
The distinction between errors and violations is often blurred but the main differences are shown in the table. As can be seen from the table, errors may be simple memory or attentional failures exacerbated by:
 Routinisation - the mark of a craftsman whereby the individual becomes so expert at exercising a particular skill, that he/she no longer consciously thinks about it allowing the mind to wander and the unexpected to happen - drivers who regularly travel the same route to the station each day suffer from this - "am I here already?"
Normalisation - the process of forgetting to be afraid - interestingly most accidents on mountains happen on the way down from the summit - only a relatively small number happen on the way up.
 Intrinsic hazard - no matter how well you defend yourself the dangers 'out there' never go away - move outside your protective 'bubble' and something or someone will get you!
Other factors include:
Creeping entropy - systems, policies and procedures grow old or fail to adjust to changing external factors thus increasing the propensity for accidents to happen.
Murphy's Law - if it can happen it will happen, but there is also Schultz' Law. Mr Schultz merely said that Murphy was an optimist!
Safe operating procedures
These are written to shape people's behaviour so as to minimise accidents. As such they form part of the system defences against accidents. Defences are installed to protect the individual, the asset or the natural environment (the 'object of harm') against uncontrolled hazards and come in two forms:
- 'Hard' defences provided by fail-safe designs, engineered safety features and mechanical barriers.
- 'Soft' defences provided by procedures, rules, regulations, specific safety instructions and training. 'Soft' defences are more easily circumvented by people than 'hard' defences and thus constitute a major challenge to any safety management system.
 Procedures are continually being amended to cover changed working conditions, new legislation, new equipment and, most particularly, to prohibit actions that have been implicated in some recent accident. Following an accident how often have you heard people (usually senior) exclaim "and what did the procedures say?" Over time these procedural changes become increasingly restrictive yet the actions necessary to get the job done haven't changed and often extend beyond these permitted behavioural boundaries. Ironically then, one of the effects of continually tightening-up procedures in order to improve system safety is to increase the likelihood of violations being committed. The scope of permitted, or allowable action shrinks to such an extent that the procedures are either routinely violated or whenever operational necessity demands. In either case the procedures are often regarded as unworkable by those whose behaviour they are supposed to govern. Whereas errors arise from various kinds of informational under-specification, many violations are prompted by procedural over-specification - a classic own goal you might say!
As already implied, system failures or weaknesses such as design, maintenance management, hardware, procedures, housekeeping, communications, organisation, training, error-enforcing conditions, incompatible goals and defences are called 'latent failures' as opposed to unsafe acts which are 'active failures'.
Performance levels
Now we come to the scientific bit. Error types can be classified at three levels:
Skill-based level
At the skill-based level, we carry out routine, highly practised tasks in a largely automatic fashion, except for occasional checks on progress. This is what people are very good at for most of the time.
Rule-based level
 We switch to the rule-based level when we notice a need to modify our largely pre-programmed behaviour in line with some change in the situation around us. This problem is often one that we have encountered before and for which we have some pre-packaged solution. It is called rule-based because we apply stored rules of the kind: if (this situation) then do (these actions). In applying these stored solutions we operate very largely by automatic pattern-matching: we automatically match the signs and symptoms of the problem to some stored solution. We may then use conscious thinking to check whether or not this solution is appropriate.
Knowledge-based level
The knowledge-based level is something we come to very reluctantly. Only when we have repeatedly failed to find a solution using known methods do we resort to the slow, effortful and highly error-prone business of thinking things through on the spot. Given time and the freedom to explore the situation with trial and error learning, we can often produce good solutions. But people are not usually at their best in an emergency - though there are some notable exceptions. Quite often, our knowledge of the problem situation is patchy, inaccurate, or both. Consciousness is also very limited in its capacity to hold information, usually not more than two or three distinct items at a time. It also behaves like a sieve, forgetting those things as we turn our attention from one aspect to another. In addition, we can be plain scared, and fear (like other strong emotions) has a way of replacing reasoned action with 'knee-jerk' or sometimes over-learned responses.
| Performance levels | Error types | Violation types |
| Skill-based | Slips and lapses | Routine violations
Optimising violations |
| Rule-based | Rule-based mistakes | Situational violations |
| Knowledge-based | Knowledge-based mistakes | Exceptional violations |
Classifying violations
Case and field studies suggest that violations can be grouped into four categories: routine violations, optimising violations, situational violations and exceptional violations. The relationship of these to both the performance levels and error types is summarised in the table below.
A few simple definitions will help clarify these violations.
Routine violations - almost invisible until there is an accident (or sometimes as the result of an audit), routine violations are promoted by a relatively indifferent environment i.e. one that rarely punishes violations or rewards compliance - "we do it like this all the time and nobody even notices."
Optimising violations - corner-cutting i.e. following the path of least resistance, sometimes also thrill seeking - "I know a better way of doing this."
 Situational violations - standard problems that are not covered in the procedures - "we can't do this any other way." An excellent example concerns railway shunters: the Rule Book prohibits shunters from remaining between wagons when wagons are being connected. Only when the wagons are stopped can the shunter get down between them to make the necessary coupling. On some occasions however, the shackle for connecting the wagons is too short to be coupled when the buffers are fully extended. The job can only therefore be done when the buffers are momentarily compressed as the wagons first come in contact with each other.
Thus the only way to join these particular wagons is by remaining between them during the connection and watching your head. The result is obvious.
 Exceptional violations - unforeseen and undefined situations - "now this is what we got trained for". The Chernobyl disaster is the best documented account of exceptional violations, however a simpler example on an oil-rig illustrates the point: a pair of engineers was inspecting a pipeline. One of them jumps into an inspection pit and is overcome by hydrogen-sulphide fumes. His companion, fully trained to handle such situations raises the alarm but then jumps down to help his partner, whereupon he too is overcome. Familiar isn't it? Nothing could have prepared the second man for the emotions that he felt on seeing his colleague in desperate need of help. Exceptional violations often involve the transgression of general survival rules rather than specific safety rules. Gut impulse is frequently stronger than the dictates of training and common-sense and quite often has fatal consequences. Survivors of such exceptional violations are often treated as heroes. Exceptional violations can sometimes be seen as an exercise of initiative even sometimes provoking reward if, that is, you get away with it.
Conclusion
There is a general formula which states:
Uncontrolled hazard + Undefended target = Unplanned event
Given that human beings, for whatever reason, are able to circumvent both controls and defences with sometimes quite remarkable cunning, the problem, for that is what it is, can be summed up as follows:
- Everyone is fallible and capable of bending the rules.
- All systems have technical and procedural shortcomings.
- Whatever you do, there's always something beyond your control that can hurt you.
Finally there is the theory of Sheep and Wolves. Studies have identified two sorts of people - sheep and wolves. Wolves accept rule violation as a norm. There are:
- Sheep in sheep's clothing.
- Wolves in wolf's clothing.
- Sheep in wolf's clothing.
- But the largest group are wolves in sheep's clothing - they haven't violated the rules - yet!
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 NO ROOM FOR ERROR is a 46-minute DVD, produced by the UK Club, on human error - how to predict when and where it will occur and prevent its consequences.
The theme is expressed in five scenarios, featuring familiar situations which lead all too often to collisions, personal injury, pollution, cargo loss and property damage. These are then reviewed and shortcomings categorised as procedure, hardware, design, maintenance management, error enforcing conditions, housekeeping, incompatible goals, communication, organisation, training and defences.
In addition to English, the DVD has subtitles in eleven languages.
Copies are available from Karl Lumbers (see contact details below).
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