ABSTRACT

This paper describes a set of procedures designed to assess the relative safety effectiveness of candidate controls for identified hazards. The procedure was developed in response to an objective to develop a systematic process to assess the relative safety effectiveness of alternative corrective actions, which considers both the type of hazard to be controlled as well as the degree of risk involved. Development of the process involved integrating: the existing DOD risk assessment scheme; the corrective action precedence process prescribed by Military Standard 882-B and; a prioritized “MORT” type energy control assessment. The decision parameters are displayed in a matrix format called a Control Rating Code (CRC), with supporting instructions, to assist in understanding the decision process, and to ensure a consistent approach between competing projects. While developed primarily for the U.S. Corps of Engineers Facility System Safety Program (FASS), this corrective action evaluation process can also be used in other system safety programs, or to assist in the selection of controls for industrial safety/occupational health hazards in more traditional safety and health programs.

INTRODUCTION

Given the objective of developing a systematic process for evaluating candidate corrective actions which considers both the type of hazard and the degree of risk, the authors explored the analytical tools available in existing system safety programs. Military Standard 882B offers system safety engineers several methods to help assess the priority for, and potential effectiveness of, corrective actions. The first of these methods involves the assessment of hazard severity and probability to assist in the establishment of priorities for corrective action and the resolution of identified hazards. The second method, System Safety Precedence 1/, provides an order of precedence for applying corrective actions to identified hazards. Beyond the scope of MIL-STND 882B, several other methodologies also appeared to be useful in assisting in the selection of corrective actions. The first of these additional methodologies is the DOD Risk Assessment Code (RAC) 2/. This process, an off shoot of the MIL-STND 882B Risk Assessment process, provides a relative assessment of risk by assigning a RAC rating to an identified hazard based on a qualitative or quantitative assessment of the probability and severity of potential mishaps. The second additional methodology considered was the Energy Barrier concept of hazard control used by the Department of Energy and the Naval Facilities Engineering Command.

We would also like to acknowledge the work of the late Dr. William Haddon Jr. for his pioneering work in the barrier concept.] As each of these methods have value, individually, in helping to select effective corrective actions, the authors attempted to incorporate the best features of each method for the Facility System Safety Program. Accordingly, CRC links the Energy Barrier Concept to the System Safety Precedence, and links this combination in turn to the DOD Risk Assessment Code. . We believe that the CRC is an improvement on existing methodologies in that it directs the analysts thinking towards an understanding of what hazard type is being controlled, how it is being controlled and, the relation of the relative effectiveness to the original risk level. Further, the results are couched in measurable, management oriented terms, to encourage action on the recommended solutions. The result of this marriage of methodologies is described in the following paragraphs