Chapter 8: Productivity of Maintenance Systems

1
Chapter 8 Productivity of Maintenance Systems

• Overview
• Input Measures
• Output Measures
• Measures within the System
• Maintenance Indices
• Metric Comparisons
• Trend Analysis

2
Input Measures

• Cost related measures
• Labor
• Materials
• Contracts
• Shop service
• Equipment rentals
• Tool crib
• Maintenance overhead
• Company or plant overhead
• Non-cost measures for each cost related measure

3
Output Measures

• Availability uptime or downtime Where S
  scheduled production time d down
  time, in days
• Reliability (MTBF) frequency of
  failure Where f number of
  failures
• MTTR duration of repair time Where df
  downtime delays from failures
• Process rate cycle time of equipment in the
  process PR ideal cycle time/actual cycle time

4
Output Measures

• Quality rate QR process/equipment precision
  (total throughput - net rejects)/ total
  throughput net rejects loss for recycled,
  rejected, scrapped, downgraded product
• Overall equipment effectiveness OEE A PR
  QR

5
Measures Within the System

• Work distribution percentage of labor-hours
  spent on various categories of work
• Delays waiting time of workers
• Compliance track compliance with various plans
  and schedules
• Backlog the amount of work planned but not yet
  scheduled or completed
• Work order status number of work orders in each
  state of completion
• Failure analysis track improvement initiatives

6
Maintenance Indices

• Maintenance indices ? measure the
  performance of maintenance
• Maintenance Administration
• Subcontracted hours per month
• Overtime hours per month
• Worker activity level
• Current Backlog (in crew-weeks)
• Total backlog (in crew-weeks)
• Worker productivity per month
• Worker utilization

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Maintenance Indices

• Composite Productivity Index (CPI) for workers
• Work orders planned and scheduled daily
• Scheduled hours vs. hours worked as scheduled
• Scheduled hours vs. hours worked
• Preventive and predictive maintenance conducted
  as scheduled
• Predictive and preventive maintenance coverage
• Maintenance effectiveness
• Overall equipment effectiveness (OEE)
• Availability

8
Maintenance Indices

• Speed (S)
• Quality (Q)
• Percentage of gross operating hours
• Number of failures in the system (NFS)
• Equipment downtime caused by breakdown
• Emergency man-hours
• Emergency and all other unscheduled man-hours
• Evaluation of predictive and preventive
  maintenance
• Maintenance costs
• Cost of maintenance to added value of production
• Maintenance cost per unit of production

9
Maintenance Indices

• Manpower component in the maintenance cost
• Cost of subcontracted maintenance
• Ratio of labor cost to material cost of
  maintenance
• Cost of maintenance-hour
• Supervision cost as a percentage of total
  maintenance cost
• Progress in cost reduction effects
• PM cost as related to breakdown maintenance
• Inventory turnover rate per year
• Cost of spare parts and material to maintenance
  cost
• Ratio of stock value to production equipment
  value

10
Metric Comparisons

• A performance measure requirements comparable
  to external data clear and easily under
  stood use readily available data broad
  consensus
• Frequent metrics for comparisons in maintenance
• Total maintenance cost per relevance value of the
  assets maintained
• Spare parts and materials in inventory cost per
  replacement value of the assets maintained
• Spare parts and materials in inventory cost per
  number of maintenance workers

11
Metric Comparisons

• Maintenance workers per total direct operating
  labor employees
• Maintenance workers per first-line supervisor
• Number of organization levels directly involved
  in maintenance
• Maintenance workers per support staff
• Training cost per maintenance worker
• Comparisons ? operating environment political,
  regulatory environment, company culture, etc.

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Trend Analysis

• Effective control for MM ? maintenance costs,
  number of breakdowns, shift in MTTR ? assess the
  trend of these indices
• Trend analysis ? corrective action