Establishing a Human Factors Program


In this chapter, we consider the elements of actually establishing a human factors program within an aviation maintenance organization. The concepts that apply to this endeavor are somewhat different than those that apply to specific topical areas, such as documentation, training, etc. In this section and throughout this chapter, we will be looking at things from a programmatic perspective, rather than with the idea of applying methods and guidelines to solve a particular problem.

Accountable Executive

The ICAO SMS framework includes the requirement for direct accountability for safety on the part of senior management. The person ultimately responsible for safety in an aviation organization is called the "accountable executive". This individual is typically a senior executive who has both the organizational clout and financial control to ensure that the SMS has the resources it needs to function properly. This person might or might not have personal oversight of the SMS or human factors programs.

Error Tolerance

Many aviation maintenance managers likely hold the idea that, if they just work hard enough and motivate people properly, they can eliminate human errors in their shop. This is a worthy, but unattainable goal. Many years of research and even more years of practical experience have demonstrated that human beings are incapable of error-free performance over any significant length of time.

Error Tolerance

A realistic goal for aviation maintenance organizations is to reduce errors as much as feasible and to structure itself and its processes in such a way that it is error tolerant. Error tolerance is the ability of an organization to continue to function safely in the presence of human errors. This does not imply that the systems are strong enough to survive errors that are allowed to propagate through them. Rather, it implies that processes are in place to catch and fix errors before they can do real damage.

Error tolerance is an achievable condition, whereas error elimination is not.

Fitness for Duty

One of the primary purposes (and effects) of establishing a human factors program is to provide a framework for ensuring that AMTs, inspectors, and supervisors are really up to the task of maintaining airplanes. This sounds almost nonsensical or, at the least, states what might be considered a redundant capability. After all, AMTs are professionals and would never knowingly work on an airplane if they feel they are not capable of performing their jobs.

However, there are many factors that affect one's fitness for duty. Everyone already knows about the obvious factors like alcohol, prescription (and other) drugs, and fatigue. Unfortunately, there are a number of other factors that can impair a person's ability to do their job. Many of these factors, like time stress, lack of experience performing particular tasks, and even task knowledge improperly passed across shifts... can mask the AMTs' knowledge that they are impaired.

Fitness for Duty

A human factors program can raise everyone's awareness of non-obvious fitness for duty factors and provide tools to assess individual fitness and deal with it when it is less than adequate.

Maintenance Resource Management (MRM)

Aircraft crews have been trained in Crew Resource Management (CRM) for at least the past 15 years. In fact, CRM is in its fourth generation of development. CRM provides crews with the perspective, awareness, and tools to deal with non-normal situations that might arise during flights. It does this by training individual crewmembers to watch each other's actions, provide feedback when things don't appear to be "right", and to assist each other to deal with abnormal events. That is, the entire crew is a team that identifies and uses the resources available to them.

AMTs working

The aviation maintenance equivalent of CRM is Maintenance Resource Management, or MRM. The goals and tools of MRM are very much aligned to their CRM counterparts. The concept of error tolerance (see above) includes the idea that all maintainers work together to identify emerging errors and correct them before they propagate to cause damage.

Proactive and Reactive Processes

The ICAO SMS framework includes some elements that are meant to identify hazards and risks before they cause harm, as well as elements that investigate incidents to identify their causes and "fix" them so they cannot cause problems in the future. These processes are sometimes called "proactive" and "reactive", respectively.


The term "resilience" is certainly not new, but it has recently been applied to the domains of safety and human error. We often use the term "error tolerance" (see above) to describe the ability of an organization to safely operate in the presence of human errors. Resilience is a broader concept and refers to the ability of organizations to adapt to sudden safety or operational challenges and then adapt back to operating in a more benign environment.


A very good example of resilience in the aviation environment is what happened to the air traffic control system in the United States on September 11, 2001. The system handled an unprecedented situation without specific procedures, but with a very high level of safety and professionalism. When the threat lessened, the ATC system reverted back to its normal level of operation.

Safety Culture

Hand in hand with the concept of error tolerance is the idea of establishing a "safety culture". This refers to building a corporate culture in which the primary motivation is maintaining the safety of workers and the public. There are many elements of a safety culture, but the general idea is that everyone who works in an organization is motivated and empowered to detect and fix situations that might cause injuries.

Management in organizations with a safety culture encourages and rewards workers who call attention to potentially unsafe conditions. Every worker knows that safety is their responsibility and they feel they are empowered to speak up and take other actions necessary to remedy unsafe conditions. Anybody in the organization can call a halt to activities until an unsafe condition is eliminated - and they are encouraged to do so.

Safety Management System

A Safety Management System, or SMS, is a combination of organizational structure, policies, procedures, and people set up in such a way that the safety of company employees, contractors and the general public is maintained at or above a predetermined level. The International Civil Aviation Organization (ICAO) has established a framework for SMS's.

Safety versus Quality

In the Safety Management System (SMS) framework of the International Civil Aviation Organization (ICAO), one of the primary components is "safety assurance". In the Transport Canada SMS framework, this component is called "quality assurance." There is sometimes a tendency to confuse the terms "safety" and "quality", but these have very different meanings in the domain of aviation maintenance.

According to the ICAO definition, "Safety is the state in which the risk of harm to persons or property damage is reduced to, and maintained at or below, an acceptable level through a continuing process of hazard identification and risk management." This definition implies that an acceptable level of risk has been established within an organization and that processes have been put in place to ensure that this level of risk is maintained or improved on a continuous basis.

Safety focuses on reducing hazards and risks. Quality focuses on the products of an aviation maintenance program.

Socio-Technical System (STS)

AMT's are familiar with technical systems. They work with (and on) them every day. However, it has become apparent to researchers working with technical organizations that the "people" aspects are often at least as important as the technology in reducing errors, increasing motivation, and creating a good workplace. The combination of technical systems with the people-to-people elements of the workplace has come to be known as a "socio-technical system", or STS.

SMS Responsibilites: An example