Chapter 13: Advances in Maintenance Concepts

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Chapter 13Advances in Maintenance Concepts

• Overview
• Reliability-centered Maintenance (RCM)
• Condition-based Maintenance (CBM)
• Total Productive Maintenance (TPM)

2
Time-based vs. Condition-based Maintenance
3
Reliability-Centered Maintenance

• Time-based overhauls of complex equipment reduce
  a little frequency of failure and uneconomical
• RCM is a logical methodology use the failure
  mode effect and criticality analysis (FMECA)
  tool for maintenance of complex equipment
• Methodology
• Select the most important equipment systems
• Define the expected performance or function of
  equipment? what constitutes a function failure

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Reliability-Centered Maintenance

• Identify the root causes of the functional
  failure
• Determine the effect in a sequence of events in
  terms of safety, production, environment, or a
  hidden effect
• Calculate the criticality of the effect of that
  failure
• Use RCM logic diagram to select the most
  appropriate maintenance tactic to prevent the
  failure
• Determine the specific action to prevent
  functional failure and its scheduling frequency
• If no preventive task is appropriate, determine
  whether it can be run to failure if a redesign is
  warranted, or if there is a test to determine the
  failure

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Reliability-Centered Maintenance

• RCM ensures correct PM actions eliminate
  inefficient PM
• RCM outputs list of maintenance actions,
  schedules, responsibilities
• RCM favors condition-based maintenance
• Simplified RCM logic tree diagram

Combination? Redesign?
n
Is failure easy spotted?
Safety or Environmental Risk?
Defect a gradual loss of function?
Prevention through Scheduled overhauls/replacemen
t?
y
n
y
Nofailure finding test
No Production risk?
Yes condition-based maintenance
Yes Time-based maintenance
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Condition-based Maintenance

• CBM uses condition data to determine more
  precisely the most advantageous moment at which
  to make a repair or replacement.
• To implement CBM program we need to answer
• Why monitor?
• What equipment/component need to be monitored?
• What monitor technologies should be used?
• How should the monitoring be done?
• How often should the monitoring be done? When?
• How should the monitoring results be interpreted
  and acted on?
• Monitoring techniques Vibration Analysis, Oil
  analysis, Ultrasonic, Penetrate, etc.

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Condition-based Maintenance

• How to access the large volume of condition
  data?? Proportional Hazards Modeling (PHM) the
  sttistical technique connects condition data to
  the corresponding failure age (EXAKT software)
• The PHM process
• Prepare and study the data
• Estimate the parameters of the PHM model
• Testing how good the PHM model is
• Establish transition probability model states,
  prob.
• Test transition behavior assumptions in different
  time intervals and interdependence of covariate
  group
• Making the optimal decision for lowest, long-run
  maintenance cost DM parameters, cost function ?
  optimal repair/replacement policy
• Sensitivity analysis of the optimal policy

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Total Productive Maintenance

• Total Productive Maintenance (TPM) is a
  management approach to maintenance that focuses
  on involving all employees in an organization in
  equipment improvement
• Objectives
• Maximize overall equipment effectiveness
  availability, process efficiency, and product
  quality
• Take a systematic approach to reliability,
  maintainability, life cycle costs
• Involve operations, material management,
  maintenance, engineering, an administration in
  equipment management

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Total Productive Maintenance

• Involve all levels of management and workers
• Improve equipment performance through small group
  activities and team performance
• TPM activities Equipment operators ? autonomous
  maintenance
• Employee empowerment operations ?maintenance
  skill transfer
• Equipment management identify major losses
• Breakdowns, setup and adjustment downtime ?
  Availability
• Idling and minor stoppages, reduced speed ?
  Efficiency
• Process defects, reduced yield ? Product quality

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Total Productive Maintenance

• TPM performance measureOEEavailability
  performance efficiency quality rate
• Availability (loading timedowntime)/loading
  time)
• Performance efficiency (theoretical cycle time
  amount processed)/operating time
• Quality rate (amount processed defective
  amount) amount processed
• OEE (theoretical cycle timeamount
  processedquality rate)/loading time

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Total Productive Maintenance

• Steps for implement TPM
• Decision to introduce TPM
• Launch an educational campaign to introduce TPM
• Create organizational to promote TPM
• Establish basic TPM policies
• Formulate a master plan for TPM development
• Hold TPM kick-off
• Improve effectiveness of each equipment
• Develop an autonomous maintenance program
• Develop a scheduled maintenance program
• Conduct training to improve operation and
  maintenance skills
• Develop an effective management program
• Perfect TPM implementation and raise TPM levels