1、 GUIDANCE NOTES ON RELIABILITY-CENTERED MAINTENANCE JULY 2004 American Bureau of Shipping Incorporated by Act of Legislature of the State of New York 1862 Copyright 2004 American Bureau of Shipping ABS Plaza 16855 Northchase Drive Houston, TX 77060 USA This Page Intentionally Left Blank ABSGUIDANCE
2、NOTES ON RELIABILITY-CENTERED MAINTENANCE .2004 iii Foreword In recent years, there has been an increase in the use of proactive maintenance techniques by Owners for repair and maintenance of machinery onboard vessels and offshore structures. The resulting preventative maintenance programs developed
3、 as a result of applying these techniques are being used by the vessels crew and shore-based repair personnel. There have been numerous advances in condition monitoring technology, trending, and increasingly more powerful planned maintenance software as a result of increased business competition. Si
4、nce 1978, ABS has cooperated with Owners on developing and implementing preventative maintenance programs. In 1984, ABS issued its first Guide for Survey Based on Preventative Maintenance Techniques with subsequent updates in 1985, 1987, 1995 and then inclusion in the Rule Requirements for Survey Af
5、ter Construction Part 7 in mid-2002. However, machinery systems have continued to become larger and more complex, requiring skilled operators with specialized knowledge of the machinery and systems onboard. The Guide for Survey Based on Reliability-centered Maintenance was issued in December 2003 to
6、 provide vessel and other marine structure Owners, managers and operators requirements for the development of a maintenance program using techniques applied in other industries for machinery systems within a maintenance philosophy referred to as Reliability-centered Maintenance (RCM). With the appli
7、cation of RCM principles, maintenance is evaluated and applied in a rational manner that provides the most value to a vessels Owner/manager/operator. Accordingly, improved equipment and system reliability onboard vessels and other marine structures can be expected by the application of this philosop
8、hy. The purpose of these Guidance Notes is to provide supplementary information for application of the requirements of the Guide for Survey Based on Reliability-centered Maintenance. Information related to equipment failure, maintenance strategies, risk considerations, conducting and documenting an
9、RCM analysis and sustaining an RCM program is provided in the main section of these Guidance Notes. An Appendix providing an overview of various condition monitoring techniques is included. A brief example RCM analysis for three propulsion engine components is provided to demonstrate the procedure.
10、ABS welcomes comments and suggestions for improvement of this Guide. Comments or suggestions can be sent electronically to rddeagle.org. This Page Intentionally Left Blank ABSGUIDANCE NOTES ON RELIABILITY-CENTERED MAINTENANCE .2004 v GUIDANCE NOTES ON RELIABILITY-CENTERED MAINTENANCE CONTENTS SECTIO
11、N 1 General1 1 Objective 1 2 Application .1 3 Defining Reliability-centered Maintenance 1 4 Definitions 2 SECTION 2 Equipment Failure7 1 Equipment Failure7 2 Equipment Failure Rate and Patterns8 3 Failure Management Strategy .12 3.1 Proactive Maintenance Tasks .13 3.2 Run-to-failure 14 3.3 One-time
12、Changes14 3.4 Servicing and Routine Inspection15 TABLE 1 Examples of Dominant Physical Failure Mechanisms for Hardware 8 TABLE 2 Six Classic Failure Rate Patterns 11 FIGURE 1 Normal, Exponential and Weibull Failure Distributions .10 FIGURE 2 Equipment Life Periods12 SECTION 3 Planned Maintenance 17
13、1 Introduction 17 2 Age-To-Failure Relationship 17 3 Planned-maintenance Task Applicability and Effectiveness18 4 Determining Planned-maintenance Task Interval19 FIGURE 1 Classic Failure Profile Used for Planned Maintenance.17 FIGURE 2 Failure Profile Illustrating the Effect of Performing a Planned
14、Task .18 vi ABSGUIDANCE NOTES ON RELIABILITY-CENTERED MAINTENANCE .2004 FIGURE 3 Safe Life Limit 19 FIGURE 4 Economic Life Limit19 SECTION 4 Condition Monitoring (Predictive) Maintenance . 21 1 Potential Failure (P-F) Diagram .21 2 The P-F Interval .22 3 Condition-monitoring Maintenance Task Applica
15、bility and Effectiveness22 4 Determining Condition-monitoring Maintenance Task Intervals23 4.1 Condition-monitoring Task Interval23 4.2 Initial Condition-monitoring Task Intervals.23 4.3 Improving the Understanding of P-F Intervals .23 5 Establishing Condition-monitoring Maintenance Task Action Limi
16、ts.24 FIGURE 1 P-F Diagram.21 SECTION 5 Failure Finding Maintenance 25 1 Introduction 25 2 Statistical View of Hidden Failures 25 3 Failure-finding Task Applicability and Effectiveness26 4 Determining Failure-finding Maintenance Task Interval 27 4.1 Mathematical Determination of Failure-finding Task
17、 Interval.27 4.2 Using Guidelines to Determine the Failure-finding Task Interval.28 TABLE 1 Example of Failure-finding Task Interval Rules .28 TABLE 2 Example of Failure-finding Task Intervals Based on MTTF28 FIGURE 1 Effect of a Failure-finding Task 26 SECTION 6 Consideration of Risks 29 1 Risks In
18、 General 29 2 Vessels and Their Risks 30 3 Risk Characterization.31 TABLE 1 Example Consequence (Severity) Categories.34 FIGURE 1 The General Risk Model 30 FIGURE 2 Example Risk Model 32 FIGURE 3 Sample Risk Matrix 33 ABSGUIDANCE NOTES ON RELIABILITY-CENTERED MAINTENANCE .2004 vii SECTION 7 Conducti
19、ng and Documenting an RCM Analysis35 1 Introduction 35 2 Defining Systems.35 2.1 Defining Ship Operating Characteristics .35 2.2 Partitioning Systems .40 3 Defining Functions and Functional Failures 43 3.1 Identifying Functions for a Functional Group.44 3.2 Identifying Functional Failures for a Func
20、tional Group46 4 Conducting an FMECA 47 4.1 Identifying Failure Modes and Effects with an FMECA .47 4.2 Considerations in Identifying Failure Modes and Failure Effects with an FMECA .51 4.3 End Effect Considerations.52 4.4 Assessing the Criticality of Failure Modes and Effects in an FMECA.52 5 Selec
21、ting a Failure Management Strategy 53 5.1 RCM Task Selection Flow Diagram 56 5.2 Maintenance Task Allocation and Planning 60 5.3 Spares Holding61 6 Documenting RCM Analyses.67 6.1 Documenting RCM Analysis Steps .67 6.2 Example RCM Analysis.69 TABLE 1 Example Operating Context of Propulsion Functiona
22、l Group .39 TABLE 2 Example Operating Modes and Operating Context.40 TABLE 3 Example Function and Functional Failure List.47 TABLE 4 Example Bottom-up FMECA Worksheet .49 TABLE 5 Example Top-down FMECA Worksheet50 TABLE 6 Failure Characteristic and Suggested Failure Management Tasks .53 TABLE 7 Summ
23、ary of Maintenance Tasks .63 TABLE 8 Summary of Spares Holding Determination 66 FIGURE 1 Diagram for RCM Analysis.36 FIGURE 2 Example Partitioning of Functional Groups .42 FIGURE 3 Example System Block Diagram .45 FIGURE 4 Simplified Task Selection Flow Diagram .54 FIGURE 5 RCM Task Selection Flow D
24、iagram.55 FIGURE 6 Spares Holding Decision Flow Diagram 64 FIGURE 6A Example of Use of Spares Holding Decision Flow Diagram65 viii ABSGUIDANCE NOTES ON RELIABILITY-CENTERED MAINTENANCE .2004 SECTION 8 Sustaining the RCM Program . 71 1 Introduction 71 2 Sustaining the Analysis71 2.1 Trend Analysis.72
25、 2.2 Maintenance Requirements Document Reviews.72 2.3 Task Packaging Reviews 72 2.4 Age Exploration Tasks 72 2.5 Failures72 2.6 Relative Ranking Analysis.75 2.7 Other Activities 75 3 Results of Sustaining Efforts75 4 Assessment of RCM Program Effectiveness.75 FIGURE 1 Process to Address Failures and
26、 Unpredicted Events 74 SECTION 9 RCM Applied to Existing Preventative Maintenance Plans . 77 1 General 77 2 System Templates .77 APPENDIX 1 Overview of Condition-monitoring Techniques 79 1 Introduction 79 2 General Condition-monitoring Categories .79 3 Selecting a Condition-monitoring Technique.80 3
27、.1 Condition Being Detected80 3.2 P-F Interval80 3.3 Measurement Precision/Sensitivity81 3.4 Skills81 3.5 Resources versus the Risk81 3.6 Environment, Location and Portability .81 4 Summary of Selected Condition-monitoring Techniques 82 4.1 Temperature Measurement Condition-monitoring Techniques82 4
28、.2 Dynamic Monitoring Condition-monitoring Techniques83 4.3 Oil Analysis Condition-monitoring Techniques 85 4.4 Corrosion Monitoring Condition-monitoring Techniques89 4.5 Nondestructive Testing Condition-monitoring Techniques91 4.6 Electrical Testing and Monitoring Condition-monitoring Techniques94
29、4.7 Observation and Surveillance Condition-monitoring Techniques96 4.8 Performance Condition-monitoring Technique 97 ABSGUIDANCE NOTES ON RELIABILITY-CENTERED MAINTENANCE .2004 ix 5 Condition-monitoring Technique Matrices .98 5.1 Failure Condition Matrix 98 5.2 Ship Equipment Matrix. .98 5.3 Matrix
30、C: Ship Component Matrix .99 6 Sources99 FIGURE 1 P-F Diagram.80 APPENDIX 2 Example RCM Analysis of a Low Speed Diesel Engine .101 1 Overview of the RCM Analysis Process 101 1.1 Identify Operating Modes and Corresponding Operating Context. 101 1.2 Define Vessel Systems . 101 1.3 Develop System Block
31、 Diagrams, Identify Functions and Functional Failures. 104 1.4 Conducting the FMECA 111 1.5 Selecting a Failure Management Strategy 126 1.6 Summary of Maintenance Tasks. 136 1.7 Summary of Spares Holding Determination 140 2 Supplemental RCM Analysis Results 143 2.1 Review of RCM Analysis Results 143
32、 2.2 Analysis of Risk Reduction 143 TABLE 1 Machinery and Utilities Operating Characteristics .102 TABLE 2 Propulsion Functional Group Operating Characteristics .102 TABLE 3 Diesel Engine System Operating Characteristics, Modes and Context103 TABLE 4 Example Function and Functional Failure List.106
33、TABLE 5 Example Consequence/Severity Level Definition Format111 TABLE 6 Probability of Failure (e.g., Frequency, Likelihood) Criteria Example Format113 TABLE 7 Risk Matrix Example Format113 TABLE 8 Example Bottom-up FMECA Worksheet .114 TABLE 9 Example Maintenance Task Selection Worksheet127 TABLE 1
34、0 Summary of Maintenance Tasks .137 TABLE 11 Summary of Spares Holding Determination 141 TABLE 12 Breakdown of Maintenance Tasks.143 TABLE 13 Propulsion Category Risk Matrix .144 x ABSGUIDANCE NOTES ON RELIABILITY-CENTERED MAINTENANCE .2004 TABLE 14 Loss of Containment Risk Matrix .144 TABLE 15 Expe
35、cted Event Frequencies for Propulsion145 TABLE 16 Expected Event Frequencies for Loss of Containment.145 FIGURE 1 Example Partitioning Diagram .104 FIGURE 2 Example System Block Diagram105 ABSGUIDANCE NOTES ON RELIABILITY-CENTERED MAINTENANCE .2004 1 SECTION 1 General 1 Objective These Guidance Note
36、s provide a summary of various maintenance techniques used in industry for machinery systems and how these techniques can be applied within a maintenance philosophy referred to as reliability-centered maintenance (RCM). With the application of RCM principles, maintenance will be evaluated and applie
37、d in a rational manner that provides the most value to a vessels Owner/Operator. Accordingly, improved equipment and system reliability onboard vessels and other marine structures can be expected by the application of this philosophy. An additional purpose of these Guidance Notes is to introduce RCM
38、 as a part of overall risk management. By understanding the risk of losses associated with equipment failures, a maintenance program can be optimized. This optimization is achieved by allocating maintenance resources to equipment maintenance according to risk impact on the vessel. For example, RCM a
39、nalysis can be employed to: i) Identify functional failures with the highest risk, which will then become the focus for further analyses ii) Identify equipment items and their failure modes that will cause high-risk functional failures iii) Determine maintenance tasks and maintenance strategies that
40、 will reduce risk to acceptable levels The principles summarized in these Guidance Notes are applied in the Guide for Survey Based on Reliability-centered Maintenance. 2 Application These Guidance Notes provide supplementary information for the use of the Guide for Survey Based on Reliability-center
41、ed Maintenance and apply to any machinery system for which a preventative maintenance plan applying risk-based principles is desired. It is applicable to both vessels and offshore facilities. 3 Defining Reliability-centered Maintenance Reliability-centered maintenance is a process of systematically
42、analyzing an engineered system to understand: i) Its functions ii) The failure modes of its equipment that support these functions iii) How then to choose an optimal course of maintenance to prevent the failure modes from occurring or to detect the failure mode before a failure occurs iv) How to det
43、ermine spare holding requirements v) How to periodically refine and modify existing maintenance over time Section 1 General 2 ABSGUIDANCE NOTES ON RELIABILITY-CENTERED MAINTENANCE .2004 The objective of RCM is to achieve reliability for all of the operating modes of a system. An RCM analysis, when p
44、roperly conducted, should answer the following seven questions: i) What are the system functions and associated performance standards? ii) How can the system fail to fulfill these functions? iii) What can cause a functional failure? iv) What happens when a failure occurs? v) What might the consequen
45、ce be when the failure occurs? vi) What can be done to detect and prevent the failure? vii) What should be done if a maintenance task cannot be found? Typically, the following tools and expertise are employed to perform RCM analyses: i) Failure modes, effects and criticality analysis (FMECA). This a
46、nalytical tool helps answer Questions 1 through 5. ii) RCM decision flow diagram. This diagram helps answer Questions 6 and 7. iii) Design, engineering and operational knowledge of the system iv) Condition-monitoring techniques v) Risk-based decision making (e.g., the frequency and the consequence o
47、f a failure in terms of its impact on safety, the environment and commercial operations) Documenting and implementing the following formalize this process: i) The analyses and the decisions taken ii) Progressive improvements based on operational and maintenance experience iii) Clear audit trails of
48、maintenance actions taken and improvements made Once these are documented and implemented, this process will be an effective system to ensure reliable and safe operation of an engineered system. Such a maintenance management system is called an RCM system. 4 Definitions The following definitions are
49、 applied to the terms used in these Guidance Notes. ABS Recognized Condition Monitoring Company: The reference to this term refers to those companies whom ABS has identified as an External Specialist. Please refer to Subsection 8/2. Baseline data: The baseline data refer to condition monitoring indications usually vibration records on rotating equipment established with the equipment item or component operating in good order when the unit first entered the Program or the first condition-monitoring data collected following an overhaul or repair procedure that invalidated the previo
