On-Condition Maintenance Using P-F Interval or Failure Detection Threshold (FDT)
On-condition maintenance relies on the capability to detect failures before they happen so that preventive maintenance can be initiated. Many failure modes exhibit signs of warning as they are about to occur. If, during an inspection, maintenance personnel can find evidence that the equipment is approaching the end of its life, then it may be possible to delay the failure, prevent it from happening or replace the equipment at the earliest convenience rather then allowing the failure to occur and possibly cause severe consequences. This article explains a methodology, using Weibull++ 7, to estimate the P-F interval or Failure Detection Threshold (FDT), which are two typical ways to describe the detectability of a failure. In addition, this article shows how to use the detectability information in the analysis of repairable systems using BlockSim 7 or RCM++ 4.

Basic Steps of Applying Reliability Centered Maintenance (RCM) – Part III
This article continues our discussion of the basic steps of applying RCM. The DEFINE stage was discussed in Issue 72 of Reliability HotWire and the ANALYZE stage was discussed in Issue 73. In this article, we examine the final stage: ACT.