Ergonomic analysis software improves workplace safety

Workplace injuries from repetitive tasks are being reduced at General Motors' Small Car Group thanks to the use of ROBCAD/Man ergonomic analysis software from Tecnomatix Technologies.

By Staff August 1, 1999

Workplace injuries from repetitive tasks are being reduced at General Motors’ Small Car Group thanks to the use of ROBCAD/Man ergonomic analysis software from Tecnomatix Technologies. The auto manufacturer is using the program to analyze ergonomic scenarios for parts handling, assembly processes, and manual welding within several operations.

In recent years, employers have increasingly recognized and reported injuries from repetitive tasks. Many have developed procedures to ensure that work is performed safely and efficiently. Although the use of robots and other automated equipment for repetitive tasks have reduced the problem, the incidence of repeated-trauma cases is still high in the vehicle manufacturing industry.

GM began taking steps to improve its ergonomic analysis procedures manually, constructing life-sized cardboard models and physically acting out the required human movements. An ergonomist would examine the force, clearance, posture, reachability, and visibility needed to perform a task. Then, people of various sizes were tested in a variety of movements to determine situations that might create stress or unsafe conditions. The activity would then be studied again to eliminate the problem areas and the actions analyzed again.

Now, using the computer-based tool, the company creates an onscreen virtual manufacturing environment to display graphically and simulate actual plant operations. Simulating the possible human movements needed on the plant floor on the computer screen lets the firm create the safest and most efficient work environments for workers.

The software provides a library of virtual human beings that vary in gender, height, weight, age, and other physical traits. Engineers choose the appropriate model, visualize and analyze human motion during the operation, and predict if a workflow design will cause ergonomic problems.

Accurate biomechanical, human models created by the program can walk and reach target locations with either hand so that analyses can be made of operation time, reachability, expended energy, lift efforts, and weight limits of human movement. Using the program, the company is able to simulate a worker unloading parts or performing an installation. It can determine how far a person must bend down or reach up, calculate a safe amount of weight to be lifted, consider handling concerns, and ascertain frequency of lifting and twisting. If a movement appears to cause strain, the software lets the virtual situation be adjusted until the strain factors disappear.

As a result of using the software, GM’s ergonomic process has become simpler and more accurate. The company uses guidelines from the National Institute of Safety and Health (NIOSH) to determine recommended weight limits for lifting as well as internal standards for other movements in com- bination with the software package.

Contact Tecnomatix Technologies at 399810 Grand River Ave., Novi, MI 48375-2108; 248-471-6140; fax: 248-471-6147; www.tecnomatix.com; or circle 201 on card.