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Ergonomics

The term ergonomics was coined by Wojciech Jastrzębowski in 1857 to mean “the science of work”1 with the goal of improving productivity and profit. He described the importance of physical, emotional, entertainment, and rational aspects of the labor and employee experience, but the context was squarely on factory-type production.

Over time, this has evolved into two, slightly different definitions.

Workplace safety

In the United States, ergonomics is most often associated with equipment or workplace design. An “ergonomic” computer mouse is supposedly more comfortable and less likely to result in repetitive strain injury. The Occupational Health and Safety Administration (OSHA) and National Institute for Occupational Safety and Health (NIOSH) provide guidance for workplace design to reduce the risk of occupational injury.

This definition is a subset of human factors engineering (HFE) that may be also called occupational health and safety. It’s related to anthropometrics (the study of human body measurements) and industrial engineering.

Human factors engineering

Around the world, ergonomics is more often synonymous with HFE. The International Ergonomics Association provides this definition: “scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data, and methods to design in order to optimize human well-being and overall system performance”.

Discussion

These different definitions of the same term came about by parallel evolution driven by broader demand for human engineering.

In the US, the term human factors engineering was coined to describe research into aviation human error during World War II. It began being applied to other industries and grew in scope to encompass a range of related fields. Some ergonomists began practicing HFE while ergonomics continued to focus on workplace impacts and fell under the umbrella of human factors.

The same demand existed for human engineering around the world for aviation and then computers, but the term HFE wasn’t in use. Instead, the application of ergonomics expanded to meet the need. This has lead to the different terms being used in different parts of the world.

Human Factors Engineering (HFE)

Human factors engineering (HFE) is a broad and multidisciplinary field that designs and evaluates the human interfaces of a system.

Don’t stop reading — that definition masks a lot of complexity. Let’s break it down:

System

INCOSE defines system as “an arrangement of parts or elements that together exhibit behaviour or meaning that the individual constituents do not. Systems can be either physical or conceptual, or a combination of both.”

Systems may include any combination of hardware, software, people, organizations, processes, information, facilities, services, tools, consumables, etc. A system can be as complex as the entire universe or as simple as two people interacting.

Human interfaces

When people hear “human interface”, they usually think software or hardware interfaces. But, interfaces really encompass any human interfaces with any of the other system components as defined above.

A great example is Crew Resource Management, which is a system for pilot interpersonal communication and shared decision making. No other system components are involved, just the humans in the cockpit1.

Think of a trip to the grocery store. You propel the cart, observe price tags and product packaging, smell the prepared foods, hear the muzak, talk to the butcher, handle products, place items on the checkstand conveyor belt, talk with the cashier, use the card reader to pay, check the accuracy of the receipt, etc. All of these are interfaces with some level of design. There’s a whole field of study on grocery store psychology.

Design and evaluate

What does it mean to design and evaluate an interface?

Obviously, it’s highly dependent on the requirements and context of the system. This is where relevant human factors expertise is required to understand the aims of the system and the interfaces to be designed, decompose those into human factors objectives, and specify how success will be evaluated.

It’s best to specify the verification method before designing, to ensure that you’re clear on the goal you’re working towards. Common metrics include user satisfaction, accuracy and error rate, speed, situation awareness, workload, usability, and engagement.

Broad and multidisciplinary

HFE covers a range of fields that may include: human-computer interaction, anthropometry, physiology, psychology, macroergonomics and organizational psychology, cognitive science, industrial design, user experience, and more.

Because HFE is such a broad field, it may take a team of experts with different specialties to effectively address the range of considerations applicable to any given system.

Summary

You should now have a better understanding of the full scope of what it means that HFE designs and evaluates the human interfaces of a system.

You may also be interested in the relationship between HFE and ergonomics and user experience (UX).

User Experience (UX)

The term user experience was coined in 1993 by Don Norman while working at Apple. He intended it to encompass a person’s entire experience related to a product, from any feelings they had prior to using it, to first seeing it in the store, getting it home, turning it on and learning how to use it, telling someone else about it, etc.

I highly recommend this short video where Mr. Norman explains this history and also complains about the frequent misuse of the word:

How does UX relate to human factors engineering?

Human factors is an umbrella term that covers a range of fields which design and evaluate the human interfaces of a system. We often think of a system as hardware and/or software, but it can also include social and organizational interfaces.

Thus, UX is very much a type of human factors. UX is distinguished from related specialties like human computer interaction (HCI) or interaction design by extending the scope of consideration beyond the product itself to any interface which might affect the user’s perceptions and feelings of the product. Yet, the goal is the same: understand the human’s needs in order to design interfaces that meet them1.

UX is very much a type of human factors.

Recently the field of customer experience (CX) has begun to emerge. CX focuses on whatever interactions a customer has with a business, which may be independent of a product user experience. CX and UX are the same basic concept, just with slightly varying scopes. CX emphasizes the design of the sales process and the customer as a user of that process. A product UX team may not consider the sales process if the “user” isn’t the same as the customer.

Why do we care about the user’s experience? For the same reason we care about all of the other functions of human factors. People seek out products and services to meet their needs. When we meet those needs better than the competition2, they’ll come back for more.

Materiel

Materiel, more commonly matériel in US English

Wikipedia entry on “Materiel”

Materiel comes from the French, hence the accented e (which, despite the dictionary definitions cited by Wikipedia, isn’t commonly used in practice). Do a something search for the term and you’ll get a googol1 of results comparing the definitions of materiel and material, but nothing to help the curious engineer or budding acquisition professional understand the practical usage of the term.

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