Introduces Reliability Centered Maintenance, strategies employed, formulation of effective maintenance plan, reduction of consequences of failures and failure rate.

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2. © RMCPL All rights reserved
Make Life Easy
&
Innovative
Thru
RCM

3. Vision
 To improve reliability of critical plant and
machinery to improve upon Productivity,
Performance and Profitability.

4. Mission
 Formulate a Reliability Centered Maintenance plan
with clear strategy
 Would be able to have a firm grasp on application of
CBM techniques in improving reliability of a plant.
 Would be able to carry out deep analysis of failure
modes in order to improve upon the inherent
reliability of a plant

5. MAINTENANCE
RELIABILITY
ENERGY
EFFICIENCY
COST & SAFETY
ENVIRONMENT
WORK LIFE
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6. RCM – some definitions
 Maintenance: Ensuring that physical assets continue to do what their users
want them to do.
 RCM: a process used to determine what must be done to ensure that any
physical asset continues to do what its users want it to do in its present
operating context.
 RCM helps people determine the best maintenance tasks in a cost
effective manner for managing the functions of physical assets – and for
managing the consequences of functional failures.
 RCM does not challenge the design of the equipment or system

7. Why RCM?
 IN ORDER TO SUCCESSFULLY COMPETE TODAY,
PLANT AVAILABILITY AND RELIABILITY MUST
BE MAINTAINED AT DESIRED LEVELS WHILE
OPERATING COSTS MUST BE KEPT AS LOW AS
REASONABLY ACHIEVABLE.
 A KEY ELEMENT IN THIS COST REDUCTION IS
CONTROLLING MAINTENANCE PRACTICES.

8. RCM - features
 Structured - Logical – nothing done without a reason
 Reduces intrusiveness and improves flexibility of maintenance teams
 Auditable -- Quantifiable results and benefits
 Induces higher skills (cognitive and physical) of technicians
 Living document

9. RCM – Benefits
 Choosing the appropriate maintenance strategies/tasks
 Formulating a structured maintenance plan and schedule
 Avoid/minimize consequence of a failure
 Reduction in maintenance tasks (25% to 50%)
 Reduction in number of failures (15% to 25%)
 Reduction in costs (25% to 50%)
 Improved quality of maintenance actions
 Maximizing Reliability, Availability, Safety
 Optimum use of maintenance resources

10. Main Benefits
1. PHASE-OUT COSTLY INTRUSIVE
INSPECTIONS
2. DEVELOP CBM PROGRAM TO
CONDITIONALLY DIRECT MAINTENANCE
ACTIVITIES.
3. DISCOVER “BAD ACTORS”
4. IDENTIFYING MORE COST-EFFECTIVE
TASKS
5. REFINE PRIORITIZATION Of Maintenance

11. Maintenance Strategies & Evolution
 On-Failure maintenance (OFM)
 Time Based Maintenance (TBM)
 Condition Based Maintenance (CBM)
 Detective Maintenance
 Design Out Maintenance (DOM)
 Opportunity Maintenance (OM)

12. On-Failure Maintenance
 Advantages:
 Can be effective where consequence of a failure is zero
 Disadvantages:
 Affects production (undesired downtime)
 Affects quality
 Large stand-by crew
 Large stock of spare parts

13. Time Based Maintenance
 Advantages:
 Can be applied to components purely subjected to time based wear (2%)
 And consequences of a failure is relatively low
 Disadvantages:
 Scheduled overhaul; however intensive; of complex equipment has little or no effect
on in-service reliability
 Increase in cost
 Lack of time
 Large stock of spare parts
 Large crew needed

14. Condition Based Maintenance
 Advantages:
 Maintenance can be done as needed
 Can be applied to random failures (minimum 68%)
 Applied where consequences of a failure ranges from Low to high
 Detects incipient and hidden failures in time
 Prevents secondary damage
 Maintenance can be planned in advance to fit production windows
 Resources can be optimized as per need and operating context
 Can be operator driven or system driven or IOT driven
 Disadvantages:
 High skill needed to implement and run a CBM system
 Multiple failures can happen at the same time stressing the maintenance system

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Pump Vibration Measurement
Thermography of switch Yard Wear debris analysis (External)
Non contact temperature measurement
Condition Based Maintenance

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What is Trend Monitoring?
60
Life Units
50
40
30
20
10
0
CM depends on the trending of parameters which
are indicators of the condition of key equipment
failure modes

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Warning
Alarm
Detection of Defects
Cause finding through
correlation

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19. Design Out Maintenance (DOM)
 Advantages:
 Can be applied to prevent repeat failures
 Minimizes or eliminates failure rate
 Generally applied where consequences of a failure is high
 Maintenance can be minimized
 Minimum resources needed to maintain assets
 Disadvantages:
 High skill needed
 Time

20. EXISTING STRATEGIES
© Dibyendu De#POWEROFSEE
TBM
Preventing age related failures
(2% to 5%)
RCM
prevents consequences of failures
OFM
no control on failures
CBM
Detects random failures(>68%)

21. Basic Steps to RCM

22. © RMCPL All rights reserved
On-Failure
Fix it when it fails
Condition Based
Maintain based upon known condition
Maintenance PlanFixed Time
Maintain based upon
calendar or running time
Design Out
Identify & design out root cause of failure

23. 7 Questions….
1. WHAT ARE THE FUNCTIONS AND RELATED
PERFORMANCE STANDARDS OF THE ASSET IN
ITS CURRENT OPERATING CONTEXT?
2. WHAT ARE THE POSSIBLE WAYS IN WHICH THE
ASSET MAY FAIL TO PERFORM ITS REQUIRED
FUNCTIONS?
3. WHAT ARE THE CAUSES OF EACH FUNCTIONAL
FAILURE OR FAILURE MODE?
4. WHAT ARE THE EVENTS THAT FOLLOW EACH
FAILURE?

24. 7 Questions…
5. WHAT IS THE SIGNIFICANCE OF
EACH FAILURE?
6. WHAT MEASURES CAN BE TAKEN
TO PREVENT FAILURE?
7. WHAT MIGHT BE THE CORRECTIVE
MEASURES THAT MAY BE TAKEN
IF THERE IS NO APPROPRIATE
PREVENTIVE STEP?

25. The RCM Process Application
 DURING EQUIPMENT DESIGN AND
DEVELOPMENT PHASE, WHEN IT IS USED TO
DEVELOP MAINTENANCE PLAN.
 DURING EQUIPMENT/PRODUCT OPERATION
AND DEPLOYMENT, THESE PLANS ARE THEN
MODIFIED BASED ON FIELD EXPERIENCE.

26. 2 criteria
 PARTS THAT ARE NOT CRITICAL TO
SAFETY –preventive maintenance tasks should
be chosen that will decrease the ownership life
ownership life cycle cost (LCC).
 PARTS THAT ARE CRITICAL TO SAFETY –
maintenance tasks should be chosen that will
that will help prevent reliability or safety from
safety from drooping to an unacceptable level,
unacceptable level, or will help reduce the
the ownership life cycle cost (LCC).

27. Heart of the thing
 INCIPIENT & HIDDEN FAILURES ARE DETECTED
AND CORRECTED – APPLICATION OF CBM
TECHNIQUES
 PROBABILITY OF FAILURE IS REDUCED –
APPLICATION OF DESIGN OUT MAINTENANCE
(DOM)
 SYSTEMIC ROOT CAUSE FAILURE ANALYSIS
(SRCFA)
 REDUCE OWNERSHIP OF LIFE CYCLE COST

28. Analysis & design of systems
 FOCUS ON CRITICAL EQUIPMENT WITH
DOCUMENTED FAILURE MODES. (Maintenance
Records)
 STRATEGY EMPHASIZING CONDITION-BASED
TASKS.
 IDENTIFYING ACTIONS THAT HELP PRECLUDE
COSTLY UNPLANNED CORRECTIVE
MAINTENANCE.
 IDENTIFYING AND REMOVING UNNECESSARY
ROUTINE PM TASKS. (Review of Equipment
Maintenance - REM)

29. The 7 step process
STEP 1:
DETERMINE EQUIPMENT/PARTS WITH HIGHEST
MAINTENANCE PRIORITY. OBTAIN APPROPRIATE
FAILURE DATA, WHICH MAY BE OBTAINED FROM – A)
A) EQUIPMENT HISTORY B) WORK ORDERS
STEP 2:
DETERMINE CONTEXTUAL FAILURE MODES
STEP 3:
PERFORM SYSTEMIC ROOT CAUSE ANALYSIS – FTA,
FTA, FMECA, SRCFA TECHNIQUES

30. Reliability Centered Maintenance
© Dibyendu De#POWEROFSEE
review
• MULL• EXCHAN
GE
• ENGAGE• NOTICE
CHANGES
?
PATTERN
S?
INTERACTI
ONS?
MINIMA
L
CHANG
ES

32. © RMCPL All rights reserved
2 3 41
0.99 x 0.99 x 0.99 x 0.99
= 0.96 ≈ 96%
Process Reliability

33. © RMCPL All rights reserved
Equipment diagram
Pump Gear Box Motor
B CA

34. Determining Criticality
Period selected = 2 yr/1yr/6m (Tp)
# Equipment Frequency
# (F)
Downtime (total)
Hrs (DT)
F x DT Rank
1 Xxxx 20 50 1000 2
2 Yyyy 5 500 2500 1
3 Zzzz 10 40 400 3
From this we also obtain:
MTBF = Tp/F
MTTR = DT/F
Steady State Reliability R = MTBF/(MTBF + MTTR) and other maintenance
parameters
Risk

35. Critical equipment for Power plant
1. MAIN STEAM AND WATER
2. FUEL HANDLING
3. CIRCULATING WATER
4. ASH HANDLING
5. SOOTBLOWING

36. Critical equipment for Power plant….
6. BOILER GAS AND AIR
7. FEEDWATER HEATER
DRAINS/EXTRACTION STEAM
8. COAL HANDLING
9. FEEDWATER
10. CONDENSATE

37. © RMCPL All rights reserved
Failure
Characteristics
Failure Probability
Graph
Condition
Monitoring
Mean Time Before
Failure
Strategy in order
of preference
Analysis of Maintenance Records permits an effective strategy to be chosen

38. The 7 step process
STEP 1:
DETERMINE EQUIPMENT/PARTS WITH HIGHEST
MAINTENANCE PRIORITY. OBTAIN APPROPRIATE
FAILURE DATA, WHICH MAY BE OBTAINED FROM – A)
A) EQUIPMENT HISTORY B) WORK ORDERS
STEP 2:
DETERMINE CONTEXTUAL FAILURE MODES
STEP 3:
PERFORM SYSTEMIC ROOT CAUSE ANALYSIS – FTA,
FTA, FMECA, SRCFA TECHNIQUES

40. Critical Equipment: Vertical Roller Coal Mill
Sub-assembly: Main Gear Box
Performance Standard: To provide constant torque to Mill table
Failure
Mode
MTBF Failure
Pattern
Warning
Effect
Root Cause Consequence Risk
Rating
Bearing
cracked
(anti-friction)
2 yrs Random Increased
noise
Bush Wear of
output shaft ->
Lateral shift of
input shaft
Full Load loss 1

43. De Diagram: S^S -> E -> Failure Mode

44. 7 step process…..
STEP 5:
CLASSIFY MAINTENANCE REQUIREMENT –
CBM, DOM, TBM, OFM, LABOUR, SPARES,
INSTRUMENTS, SOFTWARE, ETC.
STEP 6:
IMPLEMENT RCM DECISIONS. CHECK
EFFECTIVENESS.

45. Critical Equipment: Vertical Roller Coal Mill
Sub-assembly: Main Gear Box
Performance Standard: To provide constant torque to Mill
table
Maintenance Action Strategy Frequency Responsibility Remarks
1. Measure
displacement (H)
on Input shaft
2. Change Bush
material
3. Change lubricant
specification
4. Drill hole on
bearing cover
CBM
DOM
DOM
DOM
1M
One Time
One Time
One Time
MID
Engineering
Engineering
Engineering
Use low frequency
sensor
Within 3 m
Within 3 m;
Servomesh EE
320
To let out debris;
else enter bearing

46. © RMCPL All rights reserved
On-Failure
Fix it when it fails
Condition Based
Maintain based upon known condition
Maintenance PlanFixed Time
Maintain based upon
calendar or running time
Design Out
Identify & design out root cause of failure

47. RCM Maintenance Plan Distribution
2
68
5
30
Plan
OFM CBM TBM DOM
DOM
TBM CBM

48. © RMCPL All rights reserved
Life Lost
Additional Life
Time N
Risk
Just Restore
(Plan)
Restore with
Improvements
(Innovate)
Threshold

49. TPM:PEOPLE
CBM:STEM
RCM:RISK
RI:cREATIvITY
1/10
1/20
1/40
1/100
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50. Failure Modes: Verb + Noun
# Noun Verb
1 Bearing Seized
2 Bearing Worn
3 Shaft Cracked
4 Seal Worn
5 Motor Burnt
6 Contact Short-circuited
7 Coil Burnt
8 Gear Worn
9 Hinge Bent
10 Packing Leaked
# Noun Verb
11 Switch Open
12 Circuit Open
13 Valve Sticking
14 Lubricant Foaming
15 Lubricant Heated
16 Tubes Clogged
17 Rotor Bowed
18 Filter Jammed
19 Oil Contaminated
20 Contact Pitted

51. MTBF
 Mean Time Between Failures =
Time period of observation/#of failures
Usually a two years of observation period is ideal.
With lack of information a 6 months period is just enough
With no information Dynamic analysis is employed to ascertain
failure modes.

52. © RMCPL All rights reserved
Failure
Rate
Early Random Failure Wear Out
Time
Typical “Bathtub” Curve 30%

53. © RMCPL All rights reserved
70%
25%
05%
2 Pyramids (Nature of Problems)
Big
Problem
Medium
Problem
Small
Problem
Possible
> 2hr
< 2 hr
< 30m 70%
25%
05%
Wear
Early
Random

54. Failure Patterns – contd..
 Random (68 to 80% cases)  CBM is the default
 Time based (2 to 5% cases)  TBM is the default
 Early (> 10%)  DOM is the default
 Hidden (5%)  CBM/DOM is the default
 Complex  Combination of strategies needed

55. Warning Effect (e.g.)
 Vibration
 Noise
 Loss of performance
 Quality
 Overheating
 Leakage
 Corrosion
 Etc.
Actions are taken by considering both effect and causes

56. Failure Cause(s): FRECTLS (e.g.)
# Basic Cause Manifestations
1 F Unbalance
Force/ Misalignment
Inertia Looseness
Acceleration
Decelration
Impact
Torsion
Bending/Bow
Crack/Open
Fatigue (low)
Fatigue (high)
Flow
Flow turbulence
Foundation
# Basic Cause Manifestations
2 R Selective Transfer
Reactive Chemical reaction
Material
Moisture
Restrictions
3 E Dust
Environment Humidity/Dryness
Ambient Temp
EM interference
Heat transfer
Vibration
Nox/Ozone
Human
Pressure

57. Failure Cause(s): FRECTLS (e.g.)
# Basic Cause Manifestations
4 C Small Changes
Chaos Periodic attractor
& Resonance
Complexity Point attractor
Oscillating
Big changes
Non-Equilibrium
Non-Linearity
Feedback loop
5 T High
Temperature Low
Transition
# Basic Cause Manifestations
Thermal shocks
Variations
Entropy
Heat band
Radiation
Convection
Conduction
6 L Incompatible
Lubrication Additive loss
& Viscosity
Wear Moisture
Temperature

58. Failure Cause(s): FRECTLS (e.g.)
# Basic Cause Manifestations
L Wear
Lubrication Adhesive
& Abrasive (2 body)
Wear Abrasive (3 body)
(contd) Erosion
Catastrophic
Pitting
Spalling
Flaking
Brinelling
Fluting
Fretting
Corrosion (8)
Stress Corrosion
# Basic Cause Manifestations
7 S Structure/Soil
Structure Speed
Speeds Surface rough
Surfaces Sync
Space/Shape
Symmetry/Asym
Softness/Sticky
Surface interfaces
Shocks/Impact
Sound/Noise
Substance
Shorting
Separation
System design

59. Consequences and Ranking
Priority Reliability/Capability Efficiency Environment Safety Employee Worklife
1 Full Load loss Non-compliance Asset required to
protect
life/property
Protect employee
life
2 Major derating 40% or
more
Imminent
violation
3 Significant derating 20%
or more
Heat rate effect
significant
4 0% derating but possible
generation loss due to
extended asset failure
Prevents
effective
management
Redundant safety
system
Employee Safe
work
environment
5 Possible loss of generation due to
to failure of redundant equipment
Heat rate effect
moderate
Supports training
needs
6 Loss of assets causes loss of auto
function to multiple equipment or
or system
Detracts from
improvement goals
Protects equipment
from damage
7 Loss of asset causes significant
operational inconvenience
Heat rate effect minimal Provides employee
comfort
8 Loss of asset precludes normal
system or equipment operation
9 No effect No effect No effect No effect No effect

60. Maintenance Tasks are guided by
 Nature of Failure Mode, Pattern, Warning
Effect, Cause(s) and Consequence
 Frequency of a CBM task = MTBF/5
 Task takes care to avoid the
consequences
 Task takes care to detect incipient defects
 Task takes care to increase the MTBF
 Task takes care to reduce the MTTR

61. © RMCPL All rights reserved
Equipment Causes of Failure Techniques Comments
Fan Out of balance
Misalignment
Bearing damage
Aerodynamic
forces
Belt problems
Overall acceleration
Spike energy
measurement
Overall vibration
Vibration analysis
Flow measurement
Motor current
measurement
Simple application using
windowed spectra to trend
deterioration in specific
faults.
Equipment performance is
monitored by measuring
process parameters
Application of Monitoring Techniques

62. Basic Steps to RCM

63. 7 step process….
STEP 7:
BASE SUSTAINING ENGINEERING ON REAL-LIFE
LIFE EXPERIENCE DATA – LIVING RCM

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2% Unpredictable
30%
Plan
68%
Improvements
Make Life easy
&
Innovative

65. © RMCPL All rights reserved
# Audit Parameters Previous After 1year After 2years
1 No. of breakdowns per
year
57 19 3
2 % of breakdown hours 25 12 5

66. Reliability Centered Maintenance
© Dibyendu De#POWEROFSEE
# Audit Parameters Previous After 1 Year After 2 Years
1 No. of Breakdowns /Year 57 19 3
2 % of Breakdown Hours 25 12 5
effects of
ON CEMENT PLANT
57
19
3
25
12
5
0
10
20
30
40
50
60
Previous After 1 Year After 2 Years
Effect of ACM
No of BreakDowns/Year % of BreakDown Hours

67. © RMCPL All rights reserved
No. of Breakdowns (Avg/Month)
1st Year 2nd Year 3rd Year 4th Year
30
20
10
0
Number

68. © RMCPL All rights reserved
1 2 3 4 5 6 7 8 9 10 11 12
25
20
15
40
30
20
10
0
Reliability vs. Cost

69. RCM – broad steps - Implementation
 Equipment survey to establish time and costs
 Prioritise and plan the project
 Set up Study Team
 Carry out study
 Produce reports and schedules
 Monitor results, failure modes, schedules and tune the program

70. RCM – Outcome of the Study
 Facilitated sessions between –
 RCM Facilitator
 Stakeholders of an area/equipment
 Study Group produces the reports in form of a structured plan
 Reports are turned into actionable maintenance schedules and
recommendations.
 Produce reports and schedules
 Monitor results, failure modes, schedules and tune the program

71. summary
 CONCENTRATE MAINTENANCE RESOURCES WHERE THEY
WILL DO THE MOST GOOD.
 ELIMINATE UNNECESSARY AND INEFFECTIVE
MAINTENANCE.
 DEVISE THE SIMPLEST AND MOST COST-EFFECTIVE MEANS
OF MAINTAINING EQUIPMENT, OR TESTING FOR
DEGRADATION
 FOCUS PM TASKS ON PREDICTIVE OR CONDITION
MONITORING ACTIVITIES WHERE APPLICABLE. DEVELOP
A DOCUMENTED BASIS AND HISTORY FOR THE
MAINTENANCE PROGRAM.
 MAXIMIZE PLANT EMPLOYEE AND ANALYST EXPERIENCE
WHEN DETERMINING EQUIPMENT TASKS WITH

72. Reilability Centered Maintenance
© Dibyendu De#POWEROFSEE
ingredients
PEOPLE
LEADERS

73. © RMCPL All rights reserved
Once done the company
gains permanent on-
going benefits.
Prof. Tim Henry, Manchester University, U.K

74. © RMCPL All rights reserved
Contact
Dibyendu De
dde337@gmail.com
+91 7044627404 / 9836466678