scope:

PREFACE

Human errors have either directly caused or significantly contributed to many major accidents in the process industries. The American Chemistry Council, American Petroleum Institute, and their member companies recognize the importance of reducing human errors to enhance the safety, productivity, and quality of their manufacturing processes. But to improve human performance, managers need specific advice on what can be done to help prevent mistakes and to reduce the likelihood that such mistakes will lead to process upsets or accidents.

This Guide is intended for an audience of middle managers to senior executives who have different levels of knowledge about human factors engineering. It is designed to equip them with a basic understanding of the causes of human errors and to suggest ways for reducing human errors at individual facilities. It also describes how to incorporate human reliability analysis (HRA) into process safety management activities. To convey this information, we use the following steps:

• Establish a basic vocabulary (Glossary) needed to discuss human factors engineering and HRA with experts in the field

• Identify factors affecting human performance, especially those that managers can control

• Suggest ways to reduce human errors

• Describe how HRA can be incorporated in process safety management activities

Section 1 discusses the importance of improving human performance and also discusses the objectives of this Guide. Section 2 defines human error and discusses its most common causes. Section 3 identifies many specific factors in the workplace that increase the likelihood of human errors and discusses ways to improve human performance.

If a manager requires a numerical estimate of the probability of human error, there are several HRA techniques available for that purpose; Section 4 describes how these techniques can be used in conjunction with quantitative risk assessment techniques. Some concluding comments are offered in Section 5. Appendices 1 and 2 contain self-evaluation questionnaires, and Appendix 3 contains an example HRA.

We hope this Guide will help you identify ways to reduce human errors in your own facilities. However, the extent of human factors engineering knowledge that has been accumulated far exceeds what is contained in this Guide. An extensive bibliography has been included to help you find additional information about particular topics. You are strongly encouraged to use these resources in addition to this Guide.