Case Study: A Potentially Life-Saving Simplified FMEA

A high-speed production machine was experiencing wear. This wear caused the tooling to have too much play, which allowed it to rub against the product at one specific location on the machine, causing quality issues. The cost of rebuilding the machine was very high, so the manufacturing plant wanted other options of solving this problem.

An engineer came up with what seemed like an ingenious solution. Powerful magnets would be mounted just outboard of the machine at the problem area, near the tooling. These magnets would hold open the tooling as it went by, eliminating the chance of the tooling rubbing against the product. This solution was especially attractive because it would be inexpensive and easy to do, and it would solve the problem completely! The initial engineering study found no "show-stoppers" in regard to installing the magnets. Bench tests with actual magnets and tooling indicated that it would work extremely well.

Everyone was anxious to implement this project, since all the parts were readily available and would be easy to install on the machine for a test. But a requirement of the Six Sigma process was to first do a simplified FMEA to see if this could cause other issues. So, a group of production engineers, foremen, operators, maintenance people, and quality technicians were invited to a meeting to do the simplified FMEA.

Below is the simplified FMEA as derived in the meeting.

Figure 4-1. Simplified FMEA example and form

Most of the concerns that surfaced had doable and effective solutions. However, the concern that one operator had a heart pacemaker was a complete surprise; no one had any idea of how the magnets would affect the pacemaker.

On following up with the pacemaker manufacturer, it was discovered that even representatives of the manufacturer were not sure how the powerful magnets would affect the device. They did say, however, that they had serious reservations. They didn't want to commit to what level of shielding would suffice to protect the operator and were afraid of any resultant liability.

Other options were discussed, like reassigning the operator to another machine, but all of those options raised issues (such as union issues on the reassignment). The machine operator had to be free to access all areas of the machine, so a barrier physically isolating the area around the magnets was not an option.

At that point, the option of using magnets was abandoned, because there seemed to be no way to eliminate the possible risk to the operator with the pacemaker! No other low-cost solution was identified. The machine had to be rebuilt despite the high cost.

Without the simplified FMEA, the project would have been implemented, with some real risk that the operator could have been hurt or even lost his life.

Although this example is more dramatic than most, seldom is a simplified FMEA done without uncovering some issue that was previously unknown. Most of these issues can be resolved and it's easier to resolve them up front than afterwards! In this case study, the machine was rebuilt. This would probably have been the outcome in any case; the simplified FMEA prevented the risk, cost, and embarrassment of installing the magnets, dealing with the effects, and removing the magnets.