From The Ergoweb® Learning Center

New ANSI/HFES Standard for Computer Workstations a Milestone

It’s been said that a committee should never consist of more than three persons – with two of them absent for every meeting. The quip alludes to the long odds of coaxing numerous and diverse opinions into agreement. More than 50 people designed ANSI/HFES 100-2007 Human Factors Engineering of Computer Workstations. A new American National Standard, it proves that even long odds can be beaten by the right committee.   

A look at the standard reveals the scale of the achievement, while conversations with four experts who worked on the 20-year project are a window on the challenges.

Approved by the American National Standards Institute (ANSI) and published by the Human Factors and Ergonomics Society (HFES) in 2007, the milestone document is available for sale from the HFES website. ANSI/HFES 100-2007 addresses the advances in technology since the publication of an earlier version – ANSI/HFS 100-1988d – as well as the new, dynamic demands on computer workspaces. Keyboards were the only input devices discussed in the 1988 version. The 2007 standard reflects the full array of today’s technology, covering installed systems, input devices, visual displays and furniture.

The ANSI/HFES 100 Committee brought together ergonomists, designers, engineers, manufacturers, administrators and other professionals from the academic world, government circles, manufacturing and the military. Chaired by Thomas J. Albin, CPE, it was co-chaired by Marvin Dainoff, Ph.D., CPE. 

“I started participating in the drafting committee’s work as an observer, then later joined as a voting member and was finally honored to be asked to serve as the chair of the committee,” chairman Albin told The Ergonomics Report™. He described the committee meetings as “rich networking and learning experiences, with opportunities to meet, to work with, and to learn from leading scientists, peers and practitioners.”

Diverse Users

Asked about the intended audience for the publication, co-chair Dainoff noted the primary groups are “manufacturers of equipment with ergonomic features; and users, particularly system integrations, who need to assemble computer workplaces which meet user needs.”

The same question was put to Alan Hedge, Ph.D., CPE, the one-time Chair of the Environment Subcommittee. “Anyone who wants to know how they should be using a computer should find this standard helpful,” he said, listing product manufactures, designers, facility managers and end users as the target audience. 

Outlining an Achievement

According to the introduction to the standard, the specifications are intended to aid operator performance in tasks performed on computer workstations. They support a range of human factors and ergonomics objectives that aim to: enhance workstation usability by improving ease of use and ease of learning; facilitate user performance by encouraging task proficiency and error recovery; accommodate users of various physical sizes and expertise levels; maintain user performance by allowing postural changes that minimize static loads; and promote user satisfaction by fostering product acceptance and product usage.

The introduction notes that ANSI/HFES 100-2007 covers operator-machine interface issues associated with computer workstations used regularly in offices. It explains that intentionally built indoor office workplaces for the processing of text, data and simple graphics fall under this heading, and that the standard applies to computer workstations for a wide range of users. “In general the physical dimensions and force requirements are designed to accommodate at least 90 percent of the North American population.”  

The preamble points out that although increased biomechanical efficiency during work periods is desirable from a human factors and ergonomics viewpoint, the focus of the standard is to support operator performance through attention to the design aspects of computer hardware and environment interfaces.

It recommends computer workstation components, either separately or in combination with supporting software, that facilitate the diverse ability of users to perceive statically or dynamically displayed information. Grouped in this category of features are key labels, key locations and feedback from the operation of the device.

Installed Systems, Chapter 5, addresses human factors specifications for configurations of installed and functioning workstations and for their immediately surrounding ambient environments. The chapter considers the layout of computer components, lighting, acoustical noise, temperature, ventilation, equipment emissions, mechanical vibrations and electrical interference.

Input Devices, Chapter 6, identifies human factors specifications for keyboards and auxiliary input devices. Puck devices, trackballs, joysticks, stylus and light pens, tablets and overlays and touch-sensitive screens join the keyboard and the mouse in this ever-growing array.
Visual Displays, Chapter 7, provides specifications for both cathode ray tube (CRT) and flat-panel displays.

Furniture, Chapter 8, presents specifications for work surfaces, seating, and selected auxiliary components. These requirements apply to designed workplaces in which users perform computer-based tasks within the range of four reference postures. HFES points out that the Standard does not specify or advocate one particular posture for the seated or standing users of computer workstations, a departure from ANSI/HFS 100-1988d.

In its press release about the 2007 standard in November, HFES explained that ANSI/HFS 100-1988 had several limitations. It adds that the 2007 Standard seeks to correct the misunderstanding that the 90º posture used in the 1988 work was "the" correct working posture.

A Telling Exclamation Point!

Describing some of the difficulties committees face, David J. Cochran, PhD., PE, CPE, pointed out that ANSI/HFES 100-2007 is a consensus standard "so a consensus has to be reached." He explained that the players (stakeholders) are generally the industry that makes the products, the industry that uses the products, the public, labor representatives, and any scientific, academic, or medical interests.  "Getting these diverse groups to agree is very difficult," he said.  "Add to that, the paid attorneys and lobbyists, and you can have a real contentious situation.  My guess is that getting a consensus was the most difficult obstacle." 

The response from chairman Albin to a question about contention suggests that the deliberations were not fractious, but his exclamation point hints at rough areas. “I think that it would be a misrepresentation to describe the content area discussions as contentious,” he said. “However, I don’t mean to imply that members were shy about arguing the science supporting various positions! Ultimately I was always impressed by the willingness of the participants to base decisions on what the science supported.”

Dr. Dainoff challenged the central assertion about committees. “This is one of those statements that most people think is reasonable, but is questionable when examined carefully.”

But he doesn’t suggest the deliberations were easy. Producing an ergonomic standard requires the participation of multiple players, he said. For this particular one, reaching consensus required mutual understanding among at least three separate groups: designers of technology – furniture, monitors, etc. – scientific researchers and ergonomic practitioners. “Writing specifications for, say, ergonomic furniture, my area of contribution, requires consideration of existing technology – you can’t write a standard based on something that might be available in the future – plus the scientific understanding of human working postures, plus the practitioners’ experience of how technical innovations, such as advanced ergonomic furniture is actually employed in the workplace.” He noted that there are multiple constraints that need to be considered and it is unlikely that one or two people can understand the whole problem. “The challenge is coming up with a common technical language that people in different disciplines can relate to.”

“We were shooting at a moving target!” Professor Hedge replied when asked about the biggest obstacle. “We wanted the standard to be research-based but in many parts of the standard the pace of change of technology now is outstripping the pace of research to support best practices. Also, the standard has to marry with other relevant standards. For example, in the environment area the standard has to address what is happening in ventilation and air quality, lighting and acoustics, all of which are fields where standards have been developed and implemented, but often without thinking specifically about the needs of computer users.”
Despite the long odds of a large committee producing anything of value, this one succeeded. Explaining how it was achieved, Professor Hedge indicated that some parts of the process were easier than others. Where there is clear evidence for the inclusion of a recommendation then it’s easy to get a consensus, he said, but in many parts of the standard the evidence was either equivocal or absent. “In these instances, it is harder and becomes a matter of achieving a consensus on a ‘best informed guess.’”

He noted the difficulty of “[managing] a committee of over 50 members that meets intermittently, and [arriving] at a document that satisfies all needs.” For a decade the original committee was led by Bob Beaton, and a first draft was produced under his leadership, he explained. “Ultimately, the standard became the prerogative of a small group of dedicated editorial enthusiasts led by Tom Albin, which did a great job in finally getting something approved and out into the public domain.”

A Continuing Project

The November publication of ANSI/HFES 100-2007 is not the end of the story. Asked if everyone is happy with the standard, chairman Albin said he would not presume to speak for anyone but himself, but he is happy to have it approved. “It is important that the 100 standard is always viewed as a work in progress and that it is understood there will be opportunities to change the content as appropriate and necessary during the revision process.”

He explained that ANSI requires that a standard be revised or reaffirmed every five years. “Since the standard covers a fast-changing technology, I anticipate a need to revise the content and [we] are working to establish the means to maintain a current consensus regarding the content of the standard so that a revision can be accomplished in a timely manner. I anticipate having continuing meetings at the annual HFES conference to develop and maintain that consensus regarding the content of ANSI/HFES 100-2007.”

The ANSI/HFES 100 Committee must continue to defeat those long odds.

Sources: HFES; Thomas J. Albin; Dr. Marvin Dainoff; Professor Alan Hedge; Dr. David J. Cochran

This article originally appeared in The Ergonomics Report™ on 2008-02-20.