Total quality management (TQM) has become accepted practice in services. Concepts from TQM in manufacturing, such as benchmarking, diagnostic tools (fishbone diagrams, Pareto charts, and so on), and customer-driven design (through quality function deployment), have joined with such concepts as service guarantees and service recovery planning to drive the quality philosophies of many service firms. Nevertheless, there remains the monumental challenge of quality assurance when the goal is to achieve zero defects in the day-to-day provision of services. Our objective here is to suggest how another concept with proven success in manufacturing, fail-safing, can and should be applied systematically to services to achieve this goal.1
The Nature of Fail-Safing
The idea of fail-safing is to prevent the inevitable mistake from turning into a defect. The late Shigeo Shingo (known as “Mr. Improvement” in Japan) articulated this basic concept. In his writings, Shingo gave examples of how manufacturing companies have set up their equipment and manual processes to prevent errors in parts counts, sequence of work performance, and product configurations. Shingo’s concepts are seen as particularly appropriate where full-scale automation is too costly or is otherwise impractical. According to Hall, “Simple fail-safe methods are the low-cost route to parts-per-million error rates.”2
The objective of fail-safing is similar to what Taguchi methods have attempted in creating robust products and processes — that is, ensuring that they can withstand the effects of factors beyond the producer’s control. We see two main differences between fail-safing and these methods. The first is the relative complexity of Taguchi methods compared to fail-safing: Taguchi methods rely heavily on sophisticated statistical techniques to set optimal product and process parameters. Fail-safing, by contrast, does not require that a specific value be put on process parameters. It requires only the ability to discriminate good from bad. As such, it is easier to apply to intangible service processes.
The second difference is more subtle, concerning the strategy taken by each approach in controlling the process. As mentioned, Taguchi methods strive to make the product or process resistant to factors beyond its control. Fail-safing, instead, governs factors within the producer’s control and then strives to extend the scope of the control to outside factors.
Poka-Yokes as Mistake-Proofing
Central to Shingo’s approach are inspection and poka-yokes (automatic devices or methods). Shingo defines three categories of inspection, all of which should be done at the 100 percent level.