Bathtub Curve and MTBF
A failure data analysis site to support validation and decision making
Nowlan and Heap in their book, titled Reliability Centered Maintenance, consider RCM decisions basically about to answer these following three questions:
1. How does a failure occur?
2. What are its consequences?
3. What good can preventive maintenance do?
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Focusing on those independent of specific products and designs, field data are collected to validate the following three major aspects to support decisions:
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1. to validate understanding of failures
2. to validate assessment of a plan
3. to validate effectiveness of an action
1. to validate understanding of failures
Understanding of failures includes but not limited to:
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1. coupling of different failure modes
2. nature of failures, i.e. random or wear-out
3. failure percentages in different categories and/or modes
2. to validate assessment of a plan
Assessment outcomes of a maintenance plan, for example, includes but not limited to:
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1. risk ranking and task prioritization
2. cost estimation
3. spare parts determination
3. to validate effectiveness of an action
Effectiveness of a maintenance action, for example, includes but not limited to:
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1. effectiveness of maintenance/corrective actions
2. effectiveness of a condition monitoring tool/system
3. confirmation/validation of root cause analysis results
4. comparison/benchmark of maintenance workmanship and quality
5. assessment of design modification and second-source parts suppliers