The primary purpose of this study was to develop an optimized brake inspection program as a function of the criticality of brake system failure modes and degradation modes. The approach used to develop the criticality index was based on four main components: (1) a brake system computer simulation program developed at the University of Illinois; (2) weighting factors, rating a defect's potential for causing an accident, developed from the University of Indiana's Multidisciplinary Accident Investigation Study Data; (3) component outage frequencies (probability of being in a defective condition) developed from DOT's VIU data bank; and (4) a computer optimization technique (CDC's APEX III) for selecting the optimum inspection program. These four components were utilized to develop certain mathematical relationships that provide a quantitative assessment of the criticality of various brake system defects and at the same time provide a mechanism for quantitatively supporting an optimized brake inspection program. The results indicate the criticality approach provides a most effective means of inspecting brakes and at the same time reduces the number of components that must be inspected as well as determine the optimum intervals at which inspection should be made.
Abstract