Berke On Safety: The Forgotten Part Of Design

Feb. 21, 2008
I work with an ergonomics expert who has a Ph.D. in experimental psychology and 20-years experience in human factors.

He once designed a control panel that nearly eliminated the potential for operators to accidentally push a wrong button or turn a dial in the wrong direction. He did this by putting a picture of the process on the panel and putting buttons and dials where the action caused by the specific control was needed. Results were positive and immediate.

Unfortunately, this control panel is the exception rather than the rule when it comes to ergonomics. Often, human factors or ergonomics are forgotten or just dismissed.

Before we go much further, here’s a quick review of ergonomics. The word is generally taken to describe measures that make products and work areas more efficient and easier to use. Of course, it is more than that. When used properly, ergonomics integrate people, the “products” they use, and how they use them.

Ergonomics became a science during World War II when mass production took hold. Weapons needed to be easily understood and manufactured without in-depth training for workers making them or the soldiers and sailors using them. However, human error led to many deaths and damaged equipment. Many of these same errors still take place. Instrument dials and control layouts continue to create situations that end in personal injury and property damage. This is an area where ergonomics should always be applied.

Ergonomics also takes into account the psychology behind the interactions between people and machines, products, and processes. With a psychology background, ergonomics experts can forecast how people will respond to a set of circumstances. With this knowledge, design teams can solve problems early, before time or material is wasted.

Here are some problems ergonomic experts might have prevented: – The landing gear on the B-25 and B-26 bombers were controlled in opposite directions. In one plane, the pilot put the lever down to make the gear come down. In the other plane, the lever went up. Although pilots were trained, they still made mistakes. An ergonomic expert might have standardized all landing gears so that controls worked in the same direction.

– U.S. troops in Afghanistan used a target designator which gave bombing directions to pilots. After target information was sent, the device would reset to its own location. However, if the sender accidentally activated the designator before putting in a new target, the pilots would be directed to bomb the designator. A good human-factors expert would have eliminated the automatic reset.

– The Russian space program was the first to try inflated space suits. They inflated when a cosmonaut left the vehicle through a hatch. But the hatch was designed for people wearing normal clothing, so cosmonauts in inflated suits could not reenter the spaceship. In hindsight, it’s obvious the hatch should have been resized for a person wearing the inflated suit.

Ergonomics experts are also useful for designing instructions and warning labels placed on equipment. To be effective, warning labels must be seen and read. Otherwise, users would not change to safer behaviors. After warnings are written, they must be tested to determine effectiveness and proper location for them. Hazard-analysis teams should also have a human-factors expert. They often see things the rest of the team may miss.

—Lanny Berke

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