Risk assessment is increasingly becoming a critical factor to successfully reducing risks to an acceptable level (Manuele, 2001, Christensen, 2003, Main, 2003). Many industry organizations in the U.S. have or are developing methods to assist their members in conducting hazard analyses and risk assessments. Some of these industry benchmarks include:
Automotive (General Motors and others)
U.S. machine tools (ANSI B11.TR3)
European machine tools (EN 292, ISO 14121)
Robotics (ANSI/RIA R15.06)
Semiconductor (SEMI S10)
Aircraft (NSC 2000)
Medical (ANSI/AAMI/ISO 14971)
Military (MIL-STD 882D)
Packaging machines (ANSI/PMMI B155.1)
A more detailed discussion of these and other current risk assessment benchmarks is contained in Main (2003) and Manuele (2001).
Risk assessment enables users to identify possible hazards and to prompt alternative design or operational solutions to eliminate, mitigate or control the risks. Manuele (1997) defines risk assessment as:
an analysis that addresses both the probability of a hazards-related incident occurring, and the expected severity of harm or damage that may result.
Risk assessments have become increasingly important in implementing safety through design. Manuele (1997) states:
Using hazard analysis and risk assessment methods is vital in achieving an acceptable risk level for the design, the operations, and the task performance aspects of safety.
Risk assessment has recently been seen as a proactive approach for effectively implementing safety and for assuring that an acceptable level of risk is achieved. Although these and other existing hazard analysis and risk assessment methods theoretically could apply to maintenance work, maintenance activities have not been the primary focus of these methods. There are a great many safety tools available, but there are very few that are well suited to maintenance activities. For example, some of the existing risk assessment methods focus on overall system risk (equipment and operations) and resulting economic resource allocation, rather than the specific risks to maintenance personnel (e.g. Latcovich et al). As a result, a need exists to better understand the underlying problems and to develop practical solutions for identifying hazards and assessing risks in maintenance activities.
Maintenance activities involve very special sets of circumstances. Unlike operators, maintenance tasks are rarely as repetitive. Frequently maintenance involves a great deal of trouble shooting and problem solving skills. These tasks often require observation and testing of equipment in operation in order to effectively diagnose problems. The increased risks associated with maintenance activities have been noted by Mirer (1999).
Maintenance work is often hazardous, in part because the safety of personnel performing maintenance work may not be adequately considered in the design of equipment or facilities. In some instances maintenance personnel are required to disable or defeat protective devices such as guards in order to perform their tasks. In other situations time pressures loom large and quick decisions and actions are required. Although there are many ideas and opinions concerning the problems and solutions of maintenance safety and risk assessment, there are very little useful data.