You may recall from Chapter 3 and the function development process called walking the dog that you’d be walking the dog again when developing failure modes. Let’s return to the fuel supply system boundary with a reminder that it has been overly simplified to suit the purposes of this book. In an actual analysis, you would gather far more detailed information about the components in the system and in the best of situations, would have fairly easy access to the actual hardware.
Figure 5-1 shows the fuel supply system boundary. In this figure, the dog’s path is depicted as a dashed line that begins at the input pump, follows the system up and through the tank, through valves and the filter, and finally through the output pump where it exits the boundary.
Figure 5-1: Fuel supply system dog walk
Begin again at the 1,000 GPM pump that receives kerosene from the upstream process. As previously mentioned, this diagram in its current state would be of little value in an actual analysis, but it does serve nicely to illustrate the concepts in this book. In order to illustrate the process of walking the dog to develop failure modes, assume that you have physical access to this system, which means the group can go outside and look at the pump, and you have photographs and other detailed technical information readily available to the review group.
For the purpose of this example, assume the 1,000 GPM pump at the beginning of the fuel supply system is exactly like the one depicted in Figure 5-2. To illustrate the process of failure modes and failure effects, the dog walk is restricted primarily to this pump. Bear in mind that the process used for this pump is identical to the process one would use for the remainder of the system.
Figure 5-2: Fuel supply pump
Tip from Reliability Centered Maintenance: Unraveling the Mysteries by Jim Gehris
Reliability Centered Maintenance: Unraveling the Mysteries
John Moubray’s 1997 book, Reliability-Centered Maintenance, outlined a comprehensive collection of the core principles and tenets of reliability centered maintenance (RCM). Originally developed in the 1970s, RCM has since been adopted by major industries, including the United States military and the aviation industry. Nevertheless, while Moubray’s book provides an excellent academic description of topics associated with RCM, there are a number of important questions and topics that have been left unaddressed in print.
In Reliability-Centered Maintenance: Unraveling the Mysteries, author James Gehris offers a diligent and comprehensive expansion and companion that provides questions beyond the traditional RCM questions and definitions. With over thirty years of experience as a U.S. Marine Corps maintenance officer using RCM concepts and approaches, Gehris provides a road map to help ensure that any RCM analyses are properly conducted and comply with the SAE JA1011 standard for RCM.
Complete with a proven process and additional questions, this companion book to Moubray’s original work expands on the strategies, science and tools necessary to become a successful RCM facilitator or practitioner, and it further discusses ways RCM can be applied to both physical and non-physical assets.