About the Error Chain, its Links and How to Address Them, You Can Read Here:
1. The Examination of Air Accidents Led to the Error Chain
When a group of researchers analysed more than 300 incidents and accidents in aviation, they discovered that only rarely one single human mistake had preceded these events. In addition, only seldom had one member of the team been responsible. Mostly, several team members had made errors.
The researchers looked at the errors in the light of the human factors and, consequently, developed the model of the error chain with its eleven links. Each of the links represents a kind of behaviour or an experience, which can lead to mistakes, as we will discover under item 3.
2. What We Need to Know About the Links of the Error Chain
2.1. Important Figures
On average, seven of the eleven links were present in the air accidents and incidents. The minimum, which was detected in the more than 300 examined events, was four links of the error chain.
Generally speaking, the risk of an incident or accident rises if links of the error chain surface during a flight.
2.2. What Can We Deduct From the Figures for Ourselves?
Does that mean that an air accident will be prevented if the pilots let only happen three of the links during a flight?
If we transfer the concept to our work, will we always be on the safe side if we allow a maximum of three links to occur in one piece of work?
Of course, there is no one hundred percent guarantee, as potentially momentuous events depend on the nature of the combined links and additional factors. However, we minimise our risk for grievous errors.
2.3. The Error Chain Seen Before and After an Event
In hindsight, especially as a spectator watching from the outside, one is always smarter than everyone who had acted during the actual event. Hence, it is also easier to verify the links of the error chain during the investigation of an air accident.
Will this simple insight bar us from occupying ourselves with the error chain preventively?
If we know the meaning of the links, we can recognise them in our work actively.
If we attack them using the appropriate CRM concepts, we can break them.
3. We Look at the Eleven Links Separately
In the figure below, you will find the meaning of the links. We will take a look at them one at a time, using examples from our everyday lives (as appropriate) and a description. Furthermore, we will highlight which CRM concepts we can apply in order to break the error chain.
3.1. No-One Flying the Aircraft or Monitoring the Current State of Progress
An Example from Everyday Life:
Imagine, you are preparing a meal together with others. The pasta is already being boiled. A question about an ingredience to the sauce suddenly attracts all attention. In the meantime, the pot with the pasta overboils with a whiz. Everyone was occupied with a single ingredience, whilst no-one was cooking.
Description:
The pilot flying, PF, flies the plane, whilst the pilot monitoring, PM, monitors the systems and the progress of the flight in accordance with the actions of the PF.
In situations in which both take their attention from these duties and tend to one problem only, no-one is flying the aircraft any more. Thus, threats and errors might be detected and dealt with too late.
CRM Concepts Which May Help:
- Situational Awareness: Spacially, as well as concerning time, information, and resources, we keep an eye on the situation as a whole.
- Workload Management: What duties/problems have we got? Who will do what?
- Decision-making: What priorities have we got to set in what order?
3.2. A Self-Explanatory Link of the Error Chain: No-One Looking out of the Window
Description:
If none of the pilots is looking out of the window, a mid-air collision can happen, especially in areas with heavy air traffic.
A Helpful CRM Concept:
Situational Awareness, in this case spatial awareness.
3.3. Ambiguity
Example:
You are invited to a cool party by two people. However, each of them tells you a different date. As you absolutely must attend this party, naturally you don´t rest until you have found out the correct date.
Description:
During a flight, the pilots may obtain different specifications from various instruments, crew members, or air traffic control. Now, they have to find out which piece of information is correct.
Helpful CRM Concepts:
- Communication: Clarification through double-checking and reconciling of specifications
- Speak up when someone has noticed a discrepancy in order to call on the team to sort the situation out
- 10-for-10 Concept: In ten seconds the team plans the steps it will take during the next ten minutes
3.4. Distraction/Preoccupation
Description:
Distraction in aviation can be due to bad weather, technical malfunctions, or a high workload, but also private problems. The crew may be involved in a problem, which has occurred all of a sudden, so deeply that it fails to recognise additional threats or mistakes early.
CRM Concepts You Can Use:
- Situational Awareness
- Communication: elucidating the circumstances and the measures to be taken
- Workload Management
- wise use of all resources
3.5. Confusion as a Link of the Error Chain
Description:
Uncertainty, anxiety, or bafflement can be possible triggers of confusion. This holds particularly true if pilots reach the boundaries of their knowledge or their skills, notably if the situation is new to them. Consequently, mistakes tend to happen more easily.
CRM Concepts Which Bring Clarity:
- Workload Management in order to keep an overview of the situation
- good teamwork which creates an atmosphere in which uncertainties are discussed openly
- Communication: for example, briefings regarding possible problems on the flight
3.6. Using Any Undocumented Procedure
Description:
Checklists, manuals, or standard operating procedures, SOPs, cannot be written for every imaginable situation in advance. Hence, a crew has to deal with events which have not been documented yet. In this case, it is important to clarify whether the crew understands the current problems and the potential consequences.
An important difference to link number ten of the error chain is the nonexistence of written documents, whereas they, logically, in the case of a deliberate deviation do exist.
CRM Concepts Which Should be Applied First:
- Using all available resources as a team: Have they really all been applied to their full potential?
- 10-for-10 concept in order to discuss all options together
- Decision-making, also employing standardised models, for instance, FORDEC or TDODAR (item 3.2.)
3.7. Violating Limitations/Regulations
Example:
Someone has left far too late for a previously arranged lunch with a relative. Now, alone on the rural road, this person flouts the speed limit and drives a bit faster. If we also have done this ourselves before, we must admit that it was deliberately in these cases.
Description:
As in the example above, this is about the intention to potentially violate a limitation or to actually overstepping it. In aviation, limitations pertain to a wide variety of items such as rest periods, maximum number of working hours, but also airspeed limits.
Possible CRM Concepts:
- Communication: assertive speak up of a team member
- Knowledge, Skills, and Attitude: Here, it is about the professional attitude, but also about the knowledge of the limitations.
3.8. Unresolved Discrepancies are Part of the Error Chain
Description:
As in our daily lives, discrepancies in aviation can relate to opinions, information, but also changing conditions.
CRM Concepts:
- good teamwork from all members in order to address discrepancies constructively
- Communication: addressing discrepancies assertively and suggesting solutions
- Shared mental model: Have we all got the same picture of the sitation?
3.9. The Failure to Meet Targets Belongs to the Error Chain
Description:
In aviation, the failure to meet targets includes, for instance, the estimated arrival time (ETA), an assigned level or heading.
When a crew fails to meet a target, this is not considered done deliberately. Thus, it is not a violation of regulations as in item 3.7.
Helpful CRM Concepts:
- Workload management in order to keep an overview, to recognise tasks and then assign them to persons, as well as time slots
- Wise use of all personal and material resources
- timely communication of the goals, discussion of the progress
3.10. Departure from SOP
Description:
Here, a crew deviates from existing SOPs. Organisations write SOPs as solutions to potentially problematic situations. Pressure, complexity, and a lack of time may precede such deviations.
CRM Concepts:
- Using all available resources as a team, before such a departure from an SOP becomes necessary
- 10-for-10 concept in order to discuss all options together
- Decision-making including the use of standardised models
3.11. Incomplete Communication
Example:
You haven´t been given important instructions concerning a task and now you are wondering how to proceed. Due to the incomplete instructions, you have to spend time and make an effort to obtain the information you need.
Description:
On the one hand, incomplete communication means withholding important information, opinions, suggestions, and questions. On the other hand, we also subsume miscommunication here, during which discrepancies are not resolved.
CRM Concepts:
- Communication techniques: closed loop communication, standard phraseology, speak up
- Knowledge, skills, attitude: Showing a professional attitude, we convey all information we have.
- Good teamwork: A working atmosphere in which we can sort ambiguities out.
4. The Error Chain Is Not a Chain of Events
As we have seen above, the eleven links of the error chain are clearly defined and pertain to the human factors. Thus, they highlight human errors which are made before an accident.
A chain of events, however, contains environmental factors, as well, such as adverse weather conditions or technical malfunctions. These, in turn, can trigger the links of the error chain: For instance, a technical problem may attract everyone´s attention, while no-one is flying the aircraft any more.
5. We Recognise and Break the Links in Our Work
When you look at the error chain and its links, which of them surface in your profession or daily work? Which CRM concepts would you use to break them?
Let us now look at a few examples from the medical world together, which have happened in reality.
5.1.No-One is Recuscitating the Patient
During simulator training, but, unfortunately, also in real emergency rooms it has occurred that everyone involved participated in securing the patient´s airway. Thus, no-one carried out the all-important chest compressions for several minutes.
5.2. Confusion in the Emergency Department
A young doctor with only little expericence has to stich a wound on the head of a small, crying child in an overcrowded emergency department. Right before she starts, her consultant reprimands her harshly in front of the parents and the child due to the treatment she had offered another patient.
You can easily imagine that in this situation her startling, the child who cannot be calmed down, her inexperience, and the pressure created by the never-ending stream of patients confuse the young doctor. How can she now produce a fine suture with non-shaking hands?
5.3. Unresolved Discrepancies on the Scene
On an emergency scene, the ambulance crew meets a patient in her middle years with chest pain, a cough and dyspnoea. The ECG shows abnormalities. The team fail to communicate their tentative diagnosis clearly amongst themselves.
Following that, two team members think of a myocardial infarction, the other two of a pulmonary embolism. Hence, the team has no shared mental model, rendering their joint treatment difficult.
5.4. Constructive Debriefings Including the Error Chain
As you certainly are aware, in these three cases solely constructive debriefings are helpful, during which the experts involved elucidate, which links of the chain were present and what they will do differently next time. Is such a debriefing possible in every working atmosphere? We can only work on this together.
6. In My Next Blog Article You Can Read About:
Using an example, we will shed light on what circumstances and factors belonged to the chain of events and where we can detect links of the error chain.
Please feel free to browse earlier blog articles.
Author: Eva-Maria Schottdorf
Date: August 25th 2021
After one year, the articles will be removed from the blog page, updated, augmented and turned into books. You can purchase these directly on the page "A Special CRM Book Series" . The first volume is already waiting there for you.