Up Time Magazine- April/May 2008 - (Page 20) SSC Critical Crane RCM Pilot Project PM Task Type Profile (by Failure Mode) Time Directed - Non Intrusive - Intrusive Failure Finding Run To Failure None TOTAL Number of Active Tasks (TD) (TDI) (FF) (RTF) 78 (46%) 7 (4%) 10 (6%) 10 (6%) 63 (38%) -168 105 70 (42%) 15 (9%) 0 5 (3%) --168 90 specified RTF and the Straw Man had no task defined, but this was only by luck in the case of the Straw Man profile. The arrows in Figure 5 indicate the three areas where the beneficial impacts of the RCM process are most strongly felt: 1. 30 PM tasks (18%) were modified versions of the Straw Man tasks. Here the RCM analysis changed the task frequency (mostly by increasing the interval) or by increasing the basic scope of the Straw Man task. SSC Critical Crane RCM Pilot Project PM Task Similarity Profile (by Failure Mode) RCM = Strawman Task 33 (20%) RCM = Modified Current Task ▶30 (18%) 1). Frequency = 80% 2). Frequency & Task Description = 80% RCM Specifies Task ▶63 (38%) (No Strawman task exists) RCM Specifies RTF (No Strawman task exists) 41 (24%) Condition Directed (CD) The RCM-based program effectively increases the number of active PM tasks by 130% RCM Specifies RTF ▶25 (15%) (Strawman specifies a task) Note: ▶ RCM Recommendations Change Strawman Plan by 56% Figure 4 - PM Task Type Profile by Failure Mode not been specified. So the team, as a part of the pilot program, developed a “Straw Man” list of PM tasks. Basically, three of the most experienced technicians on the team took existing component level tasks that were already documented from current operations and applied their collective tribal knowledge to define the component Straw Man list. This Straw Man represents the PM program that would have been used, absent RCM, and is thus a very reasonable set of data for the comparison. Figure 4 shows the breakout at the failure mode level of the 168 decisions by PM task type, including RTF for the RCM results and none for the Straw Man (i.e. with the Straw Man, deliberate decisions were not made to exclude any PM action). The striking thing here is the number of active tasks for each profile is nearly identical (105 vs. 90). In fact, the total Time Directed tasks for each profile is identical at 85. From a PM Task Type point of view, the RCM analysis was moderately successful in introducing some Condition Directed Tasks (PdM) where none would have otherwise been specified, and did increase the Failure Finding Tasks by 50% since we knew from the analysis exactly where the most significant hidden failure modes were located. But, the really important benefits from the RCM process are revealed in Figure 5, the PM Task Similarity Profile. Here, we see five specific statements which characterize where similarities or differences exist between RCM and Straw Man PM tasks. Notice that from a decision point of view only 1 in 5 (20%) tasks were identical. By default another 1 in 4 (24%) appeared to be identical where RCM Figure 5 - PM Task Similarity Profile 2. 39 PM tasks (23%) were added by the RCM analysis where none existed in the Straw Man. This was made possible by the fact that we knew, at the failure mode level, where the critical failures could occur. The Straw Man never went to that level of definition. 3. Conversely, 25 PM tasks (15%) were designated RTF by the RCM analysis where the Straw Man would have spent resources to do a task. Again, we knew where the non-critical failure modes resided and could thus specify RTF without any risk. Overall, the RCM recommendation changed the Straw Man plan by 56%. were not directly related to maintenance issues. We have taken these lessons learned and applied them to our critical crane design standard. Design changes will make new cranes easier to operate, service and maintain. For example, the detailed analysis of the hydraulic emergency drum brake system sparked discussion that has led to design changes that will greatly reduce the chance of clean room contamination and still prevent a load free fall. Another IOI indicated a need to establish crane maintenance metrics so that trends can be properly measured and evaluated. Other IOI’s showed the discrepancy between what was wanted for this crane and what was actually provided. This has led to better clarification of the details in the design standard and improvements to the control systems and operator interfaces. Many improvements to the Lockheed Martin Space Systems Company critical crane maintenance program and design standard were identified as a direct result of the Reliability Centered Maintenance study on this crane. Lessons Learned This study provided many opportunities for improvements to LMSSC’s crane maintenance program and critical crane design standards. We were able to use information from the study to eliminate unnecessary, intrusive maintenance tasks and add tasks which specifically addressed the enhanced safety systems of our critical cranes. This will provide a more focused approach to maintenance and make better use of the time spent by the maintenance staff. The “Items of Interest (IOI)” feature of the Worksaver software was a very valuable tool. It enabled the team to document points brought up in the course of discussion that Where To Go From Here Now that we have completed the Classical RCM Process for one of our critical cranes, developing a solid implementation plan becomes the center of our focus. The fact that our maintenance organization has experience with other projects is a significant benefit. Move to CMMS The first step is writing RCM maintenance tasks descriptions for this specific crane april/may 2008 20
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