Conclusion: You need human factors engineering expertise to see design hazards that are hiding in "plain sight!".

BACKGROUND The Human Factors Engineering (HFE) series was launched to share the ideas and methods to aid deeper analyses of adverse events and provide tools to ensure more effective and lasting therapies. Articles in the series showed how human limitations and capabilities were important design issues in a variety of areas, ranging from labels and warnings to work place design and complex decision support systems. REMAINING QUESTIONS After reading all the articles, one might ask a number of questions, such as who made all our "puzzle rooms?" How did it happen that so many device components "masquerade" as each other yet perform very distinct functions? What are the procurement systems that gave us medication containers, tubing, and connectors that are hard to see and easy to misconnect? Behind all those questions remains a key query: what stands in the way of developing or hiring the expertise to see and fix these catastrophic design hazards "hiding in plain sight?" SUMMARY AND CONCLUSION HFE has already found its way into health care organizations and industry. As with most large changes in professions and industries, many small steps will need to be taken toward applying HFE methods and principles to the large problems of patient safety. But there already ample incentives and tools to start transforming your health care delivery or manufacturing organization.