Human Factors: Programs Continue to Advance

The term “Human Factors” (HF) provokes a wide range of definitions and emotions in ramp safety circles. HF programs, simply stated, promote safe and efficient work with an eye on human performance. This article takes a quick look back at nearly 30...


The term “Human Factors” (HF) provokes a wide range of definitions and emotions in ramp safety circles. HF programs, simply stated, promote safe and efficient work with an eye on human performance. This article takes a quick look back at nearly 30 years of human factors in aviation. HF programs have evolved to be a critical part of Safety Management Systems by looking not only at the human, but at the organization. This is the first in a series of articles that will showcase applied human factors research products that can be implemented today.

 

Historical Human Factors

Today’s ramp and maintenance HF programs have been around since the late 80s when the U.S. Congress gave FAA a mandate and funding to study and apply human factors to all aviation workers. HF consultants and scientists used a number of useful models, acronyms, and other memory aids to simplify HF concepts. Table 1 lists the famous ones, available through a quick Google search.

 

These memory aides are an excellent human factors review. Heinrich (1972) used a floating iceberg to suggest that the largest and most dangerous part of the iceberg is below the water line as shown in Figure 1 (page 27). The tip of the error iceberg represents the accident that we investigate. However, there are thousands of small errors below the surface that really lead to problems. For example, a cargo door may have not been sufficiently fastened. While the unsealed door was the tip of the iceberg, the contributing causes were lack of enough qualified personnel, a rushed departure, and a faulty belt loader that distracted the crew.

By 1992 the Boeing Company created a system to investigate the many small events, often human errors that contributed to a serious incident. Boeing named their process Maintenance Error Decision Aid (MEDA). It is used by more than 800 airlines worldwide to investigate ramp, maintenance, and other aviation events.

Many HF memory concepts emerged in the early- to mid-90s. James Reason used a stack of Swiss cheese to represent all of the safety and redundancy in the aviation system. When many slices of cheese are stacked together, none of the holes line up and the system is protected. However, sometimes the holes can align and permit the pile of cheese to have a weakness that can be penetrated by the many threats surrounding the usually safe aviation system. Figure 2 shows a Lufthansa Technical Training rendition of Reason’s Swiss Cheese, using terms like “contributing factors” and “corrective actions,” from Boeing’s MEDA.

No discussion of aviation HF is complete without mentioning Gordon Dupont’s “Dirty Dozen.” The Dirty Dozen represents 12 common contributors to human error, including lack of assertiveness, poor communication, fatigue, lack of knowledge, lack of resources and six other contributors. The concept has become a mandated part of human factors training by most aviation authorities.

Bill Johnson and Mike Maddox introduced “PEAR” as a way to recall and consider HF issues in any organization. PEAR reminds you to consider the “People” in the organization; the “Environment” in which they worked, including the physical and the social environment; the “Actions” they must perform; and all of the “Resources” necessary to complete the job. Figure 3 shows PEAR.

Human Factors Today

Initially, aviation HF focused on specific human characteristics of pilots and other aviation workers. That singular focus expanded to the study of teams. The term, “Crew Resource Management” (CRM), emerged. The CRM concepts focused on communication, leadership, and how a small groups worked together to focus on flight safety, personal safety, and on work efficiency.

Today’s HF looks beyond equipment design, individual performance, and teamwork to the concept of “Safety Culture.” That means that everyone in the organization places safety as the highest priority. Each employee can explain their contribution to the safety of the organization. Today’s HF focus is broadened to the entire organization. The organization has the responsibility to manage safety with Safety Management Systems.

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