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4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/ARP4176 AEROSPACE RECOMMENDED PRACTICE ARP4176 Issued 2013-02 Superseding AIR4176
5、 Determination of Costs and Benefits from Implementing an Engine Health Management System RATIONALE This Aerospace Recommended Practice (ARP) provides insight into how to create a cost benefit analysis to determine the justification for implementing a propulsion/engine health management system. The
6、considerable advancement of health management (HM) tools and capabilities in the past 10 years, coupled with some successful applications to legacy and new engines drove the need to re-write the original AIR and provide more specific guidance, thus creating the need for an ARP. Moreover, there has b
7、een increasing requests in recent years by potential implementers, both commercial and military, to better understand how to make a convincing business case within their organizations, This, for many, has become the stumbling block that prevents implementation of an Engine Health Management System.
8、TABLE OF CONTENTS 1. SCOPE 4 1.1 Purpose . 4 1.2 Approach . 4 2. REFERENCES 4 2.1 Applicable Documents 4 2.1.1 SAE Publications . 4 2.1.2 Other Documents 5 2.2 Abbreviations 5 3. INTRODUCTION. 6 3.1 Motivation for Implementing a Prognostics and Health Management System . 6 3.2 Fundamental Considerat
9、ions Preceding the Cost Benefit Analysis . 7 4. FACTORS INFLUENCING COST BENEFIT STUDIES AND ANALYSES 8 4.1 PHM System Complexity 8 4.2 Usage: Military versus Commercial 8 4.3 Legacy versus New Platforms 9 4.3.1 Impact on Design 9 4.4 Performance versus Reliability or Sustainment 10 4.5 Cost Savings
10、 versus Cost Avoidance . 10 5. COSTS FOR CONSIDERATION IN AN ENGINE PHM COST BENEFIT STUDY . 10 5.1 PHM System Scope and Overview . 10 5.1.1 Data Generation and Acquisition 10 5.1.2 Data Capture . 11 5.1.3 Vehicle/Platform Integration 11 5.1.4 Communications (including Satellite and Other Relay Prov
11、isions) 11 5.1.5 Ground Station 11 5.1.6 Information Delivery 11 5.1.7 Data Storage and Archiving 11 SAE ARP4176 Page 2 of 34 5.1.8 Software (including Software Maintenance) . 11 5.1.9 Technical Support for Users . 12 5.1.10 Data Analysis and System Upgrades to Address Emerging Fault Modes and Evolv
12、ing Needs 12 5.1.11 Electronic Component Obsolescence . 12 5.1.12 Discussion . 12 5.2 Development Costs . 13 5.2.1 Requirements Definition 13 5.3 Design and Development 13 5.3.1 Build and Qualification 13 5.4 Production Costs . 14 5.5 Operational Costs . 14 5.5.1 Labor for Data Handling, Analysis, S
13、torage, and Transmission . 14 5.5.2 Data Transmission and Storage Costs . 14 5.5.3 Additional Fuel Costs 14 5.5.4 Unnecessary Maintenance due to PHM System “False Alarms” . 15 5.6 PHM System Sustainment Costs 15 5.6.1 PHM System Training . 15 5.6.2 PHM System Upgrades 15 5.6.3 PHM System Maintenance
14、 . 15 5.6.4 Component Obsolescence 15 6. BENEFITS FOR CONSIDERATION IN AN ENGINE PHM COST BENEFIT STUDY . 17 6.1 Fuel Savings . 17 6.1.1 Fewer Ground Runs for System Checks or Diagnoses 17 6.1.2 Fewer Mission Aborts . 17 6.1.3 Increased Propulsive Efficiency through More Systematic Monitoring of Deg
15、rading Engines . 17 6.2 Planning and Anticipating Engine Changes. . 17 6.3 Identification of Faulty Components Such As Control Valves and Air Bleeds 18 6.4 Trending of Performance Degradation and Early Corrective Action 18 6.5 Business Benefits 18 6.5.1 Warranty/Guarantee Mitigation . 18 6.5.2 Power
16、-by-the-hour Cost Reduction 18 6.5.3 Service Sales 19 6.5.4 Life Extension of Life-limited Parts (LLP) 19 6.5.5 Increased Residual Value . 19 6.6 Reduced Weight of Propulsion System through Reduced Redundancy and Conservatism 20 6.7 Maintenance Savings 20 6.7.1 Reduced Line Maintenance Labor-hours/S
17、taffing 20 6.7.2 Reduced Shop Maintenance Labor-hours/Staffing . 20 6.7.3 Reduced Number of LRUs Returned For Bench Check/Overhaul and Reduced “Back Shop” Labor-Hours/Staffing . 20 6.7.4 Reduced Secondary Damage from Early Detection of Incipient Failures 20 6.7.5 Improved Parts Life from Early Detec
18、tion and Correction of Component Performance Degradation 21 6.8 Operational Savings 21 6.8.1 Fewer In-flight Shut Downs (IFSD) and Unplanned Engine Removals (UER) . 21 6.8.2 Greater Platform Availability . 21 6.9 Capital Investment 21 6.9.1 Fewer Mission Aborts Prior to Takeoff and After Dispatch .
19、21 6.9.2 Reduced Spare Equipment, Parts and Material Stocks . 22 6.9.3 Reduced Maintenance Facilities and Equipment at All Levels . 22 6.9.4 Reduced Investment in Equipment and Facilities Due To Lower Demand for Vehicles, Spares, and Material 22 6.10 Incidental Costs . 22 6.10.1 Marginally Reduced D
20、ependence on Strategic Materials and Obsolete Components 22 SAE ARP4176 Page 3 of 34 7. CHALLENGES ASSOCIATED WITH COMPLETING A COST BENEFIT STUDY 23 7.1 Qualitative Values . 23 7.2 Desired Fidelity . 23 7.3 PHM System Confidence 24 7.4 Is a Cost Benefit Study Really Necessary? 24 7.5 PHM is Too Goo
21、d to Be True 24 8. EXAMPLES OF PHM IMPLEMENTATION AND ASSOCIATED COST ANALYSIS MODELS . 25 8.1 U.S. Army Helicopters . 25 8.1.1 Implementation of CBM 25 8.2 Financial Tools 26 8.2.1 Real Options Analysis (Reference 2) 26 8.2.2 Actuarial Science (Reference 3): 26 8.3 Integration of a PHM model (Refer
22、ence 4) . 26 8.4 System Dynamics Approach/Perspective . 27 8.4.1 Business Case Scenarios using System Dynamics Modeling (Reference 5) 27 9. SUMMARY 34 10. NOTES 34 FIGURE 1 BASIC PHM PROCESS FLOW 7 FIGURE 2 A GENERALIZED PHM VALUE MODEL . 23 FIGURE 3 U.S. ARMY HELICOPTER FLEETS ARE LEADING THE WAY F
23、OR ON-BOARD PHM APPLICATIONS25 FIGURE 4 BUSINESS CASE 1 29 FIGURE 5 BUSINESS CASE 2 30 FIGURE 6 BUSINESS CASE 3 31 FIGURE 7 BUSINESS CASE 4 33 TABLE 1 PHM SYSTEM IMPLEMENTATION RELATIVE COST AND WEIGHT IMPACTS (ESTIMATED) 16 TABLE 2 ASSUMPTIONS 28 TABLE 3 ESTIMATED PHM COSTS . 28 TABLE 4 BUSINESS CA
24、SE 1: ROI AND NEW SAVINGS BASED ON A 10-YEAR PERIOD 30 TABLE 5 BUSINESS CASE 2: ROI AND NEW SAVINGS BASED ON A 10-YEAR PERIOD 31 TABLE 6 BUSINESS CASE 3: ROI AND NEW SAVINGS BASED ON A 10-YEAR PERIOD 32 TABLE 7 BUSINESS CASE 4: ROI AND NEW SAVINGS BASED ON A 10-YEAR PERIOD 32 TABLE 8 OVERALL ROI AND
25、 SAVINGS BASED ON A 10-YEAR PERIOD 33 SAE ARP4176 Page 4 of 34 1. SCOPE This ARP provides an insight into how to approach a cost benefit analysis (CBA) to determine the return on investment (ROI) that would result from implementing a propulsion Prognostics and Health Management (PHM) system on an ai
26、r vehicle. It describes the complexity of features that can be considered in the analysis, the different tools and approaches for conducting a CBA and differentiates between military and commercial applications. This document is intended to help those who might not necessarily have a deep technical
27、understanding or familiarity with PHM systems but want to either quantify or understand the economic benefits (i.e., the value proposition) that a PHM system could provide. 1.1 Purpose This ARP is not intended to be used as a standard or legal document but is compiled to help the increasing number o
28、f people who want to compute a PHM Cost Benefit Analysis prior to implementing such a system on a platform. 1.2 Approach The approach taken was to identify the parameters that were relevant for consideration in a cost benefit analysis so that the boundaries of a specific problem could be defined fro
29、m the outset. Several recent and worthy papers presented at conferences on the subject matter were studied and as much information as possible was obtained from the aerospace engine manufacturers and the U.S. Department of Defense (DoD) to identify effective tools and techniques. The various methods
30、 were assessed by an E-32 team for their application to specific scenarios (e.g., military or commercial operation, legacy or new engines) and the parameters utilized by each scenario. The end result is a document that offers the reader various solution paths so that the one most appropriate to the
31、specific situation can be used or adapted. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the d
32、ate of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1.1 SAE Public
33、ations Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. ARP1587 Aircraft Gas Turbine Engine Health Management System Guide AIR1828 Guide to Engine Lubrication System Monitoring A
34、IR1839 A Guide to Aircraft Turbine Engine Vibration Monitoring Systems AIR1871 Lessons Learned from Developing, Implementing, and Operating a Health Management System for Propulsion and Drive Train Systems AIR4061 Guidelines for Integrating Typical Engine Health Management Functions Within Aircraft
35、Systems AIR4175 A Guide to the Development of a Ground Station for Engine Condition Monitoring ARP4761 Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment SAE ARP4176 Page 5 of 34 AIR5317 A Guide to APU Health Management AIR5871 Prognostics for
36、 Gas Turbine Engines 2.1.2 Other Documents Reference 1: AHS2011-000291, Verification and Validation Process for CBM Maintenance Credits dated 24 Feb 2011 Reference 2: “Real Options Analysis as a New Economic Tool Linking CBM Investments to Business Strategy”. Presented by Fred Discenzo, PhD, Rockwel
37、l Automation, at the 56thMeeting of the MFPT Society, April 2002. Available from Society for Machinery Failure Prevention Technology, 5100 Springfield St., Ste 420, Dayton OH 45431-1264 (937)-256-2285, www.mfpt.org Reference 3: “The Business of PHM: An Actuarial Engineering Perspective,” Keynote add
38、ress by Sameer Vittal at the PHM Conference, Portland, OR, (www.phmsociety.org/sites/phmsociety.org/files/PHMconference2010_SameerVittal.pdf) Oct, 2010 Reference 4: “Metrics, Models, and Scenarios for Evaluating PHM Effects on Logistics Support”. Presented by Joel Luna, Frontier Technology, Annual C
39、onference of the Prognostics and Health Management Society, San Diego, 2009. Available from the PHM Society, www.phmsociety.org Reference 5: “Economic Modeling for Prognostic Health Management”, Presented by Ron Shroder and Nick Frankle, Frontier Technology Inc, at the 2009 conference of the Society
40、 for Machinery Failure Prevention Technology, Dayton OH. Available from Society for MFPT, 5100 Springfield St., Ste 420, Dayton OH 45431-1264 (937)-256-2285, www.mfpt.org 2.2 Abbreviations ACARS Aircrew Communications Addressing and Reporting System AIR Aerospace Information Report ARP Aerospace Rec
41、ommended Practice ATO Aborted Take Off CBA Cost Benefit Analysis CBM Condition-Based Maintenance CEDU Central Engine Diagnostics Unit DoD Department of Defense DSC Digital Source Collector ETOPS Extended (Twin Engine) Operations EFH Engine Flight Hour EKG Echo Cardiogram FADEC Full Authority Digital
42、 Engine Control FMECA Failure Modes, Effects, and Criticality Analysis HM Health Management IFSD In-Flight Shutdown JSF Joint Strike Fighter LCC Life Cycle Cost LLP Life-Limited Part LRU Line-Replaceable Unit MRO Maintenance, Repair, and Overhaul MTBR Mean Time Between Removals NFF No Fault Found OE
43、M Original Equipment Manufacturer PHM Prognostics and Health Management PHMU Prognostics and Health Management Unit PTCRB PCS (Personal Communication System) Type Certification Review Board SAE ARP4176 Page 6 of 34 ROI Return on Investment SER Scheduled Engine Removal TAC Total Accumulated Cycles TO
44、W Time on Wing UAV Unmanned Air Vehicle UER Unscheduled Engine Removal V thereafter, the other motivational drivers for PHM system installation include higher affordability, increased equipment usage, enhanced reliability, reduced spares holdings, etc., which are described later (Section 6) and will
45、 have differing priorities depending on the specific user or implementer of the system. SAE ARP4176 Page 7 of 34 ACQUIREDATADELIVERDATAANALYZE+ REPORTEXECUTEACTIONSWHATWHEREHOWSENSEDATAFIGURE 1 - BASIC PHM PROCESS FLOW 3.2 Fundamental Considerations Preceding the Cost Benefit Analysis The initial en
46、try point for considering the implementation of a PHM system on any piece of equipment is to identify and define the specific failures or modes of failure that need to be detected. The PHM system will thus be configured to identify system degradations that will lead to a failure that is either unsaf
47、e, expensive, leads to mission compromise or failure, or creates major inconvenience to the operator or its customers. Examples of such are engine disk bursts (too dangerous), and unscheduled engine changes in remote operating bases (costly for the operator and major inconvenience incurred by the cu
48、stomers, usually resulting in increased costs to the operator and long-remembered customer dissatisfaction). There are a great many other failures which could be termed innocuous in that they are easily repairable, dont pose an unsafe condition or in-flight hazard, or are inexpensive to fix (althoug
49、h it is recognized that some of these, if left unattended, could lead to larger costlier issues in the future). Many airline passengers experience such failures with overhead seat lighting, personal entertainment malfunctions, etc. Other failures are typically remedied by “quick fixes” to the aircraft, conducted by maintenance personnel while the aircraft is at the gate but which might nonetheless still delay the planes departure. It is pr
