STLE 2012 CBM and Reliability Engineering Conference

“Achieving Reliability from Data” at CerrejónA Living Reliability Centered Maintenance (LRCM) project

Gerardo Vargas, Carbones del Cerrejón Ltda.Juan Carlos Consuegra, Carbones del Cerrejón Ltda.

Oscar Hoyos Living Reliability (presenter)Murray Wiseman, OMDEC Inc.

Dr. Daming Lin, OMDEC Inc.

Introduction – Main Actors

•Carbones del Cerrejón – World´s largest export coal mining operation

•OMDEC – EXAKT CBM Optimizing Software

•Living Reliability – Consultants in Living RCM (LRCM)

Commonly used terms

• LRCM: Living Reliability Centered Maintenance• CMMS: Computerized Maintenance Management System• Event type: How a failure mode’s life cycle ends? By:

Potential Failure (PF)Functional Failure (FF)Suspension (S)

• PHM: Proportional Hazard Model. Extends Weibull to include CBM data.

• CBM: Condition Based Maintenance

RCM

1. What are the item’s functions to be conserved? (The performance requirement)

2. In what ways can these functions be compromised? (The failure or failed state)

3. What causes the loss of function? (The failure mode)4. What happens? (The effects)5. How does it matter? (The consequences (H, S, O, N)?6. What maintenance task should be done to avoid or lessen the

consequences?7. What if no appropriate maintenance task can be found?

Introduction - Assertions

1.Without an adequate data sample there can be no Reliability Analysis (RA)

2.Without analysis there can be no systematic verifiable improvement in reliability or in operational economy.

Introduction - What is a sample?Sam

ple

Right (Temporary) Suspensions:

EF, ES: endings by failure, suspensionB: Beginnings

Life cycles:

Left Suspensions:

Cal

end

ar T

ime

Work ord. 1, FF RCMREF15

Work ord. 2, FF RCMREF16

Work ord. 3, FF RCMREF16

Work ord. 4, S RCMREF15

Work ord. 5, PF RCMREF15

CMMS Work ordersEF15

B15

EF16

B16

EF16

B16

ES15

B15

EF15

B15

Events table

Objective

To describe a method wherein completed maintenance work orders capture RA enabling information

Agenda

• Introduction• Objective• CBM decisions• The CBM model• The obstacles• The Living RCM solution• Results• Summary• Questions and discussion

CBM Decisions

Three decisions whether to:

1.Stop the equipment as soon as possible and perform a specific preventative action as indicated by the monitored data, or

2.Schedule an indicated preventative maintenance action within a specific and safe time period, or

3.Carry on with the normal operation of the equipment until the next CBM inspection and evaluation.

Cerrejon´s requirements for CBM

CBM Method: Oil AnalysisFailure mode: General Engine WearRULE: 2090 hoursStdDev: 1445 hours

The three criteria1. Optimal2. Automated3. Verifiable

CBM optimal model

Predictive Model+

Hazard model

MaxWSDropet

th

06944.0

1781.0

27092709

781.0

RULE and Confidence interval

Decision based on:Probability

RULE

Scatter

Cost model EXAKT Decision based on:

Cost and Probability

The obstacles

There are two possible reasons for the unsatisfactory performance ofCBM decision model.

1. The condition monitoring variables that are available to the CBM program intrinsically bear little or no relationship to the actual failure modes that occur in the fleet. Or,

2. The data sample used to build the predictive model does not distinguish between Failure and Suspension.

Obstacle 1 “ the CBM variable have no relationship to actual failure modes”

Low predictabilityLow predictability

Working age t

PDF

f(t)

Weibull Analysis

FEppm

100Working age t

PDF

f(t)

High predictabilityHigh predictability

PHM Analysis

Non (low) influential indicators

Obstacle 1 “ the CBM variable have no relationship to actual failure modes”

Misreporting suspensions as failures (or potential failures) will weaken the model

in two ways:

1.It will inflate the shape parameter causing decisions to be predominantly age based, regardless of intrinsically good (predictive) CBM condition indicators. And,2.….

Obstacle 2 Mistaking suspensions for failures

2. It will increase the scatter, and consequently confidence in prediction.

This point raises a subject that RCM stresses as one of prime importance. What shall be the “standard” used to declare failure?

Obstacle 2 Mistaking suspensions for failures

The Living RCM solution

1. Capturing the right information in the work orders system (CMMS)

2. Generating automatically a sample for RA

3. Motivation, leadership, and training

4. Low and high level performance metrics

1. Capturing the right information in the work orders system (CMMS)

Work Order

RCM concepts

Ellipse - Baseman

Free text (updates)•What I did?

•What I found?

Event type (FF, FP, S)

Living Reliability

SystemComponent

Function

Failure

Failure mode

Efects

RCM as the main language of maintenance.

Updates to the RCM Knowledge base

1. Capturing the right information in the work orders system (CMMS)

2. Generating automatically a sample for RA

An LRCM project implementation succeeds based on a realization that personnel respond to the intangibles:

1. Recognition, 2. Empowerment, 3. Interest by management in their activities, and 4. Training.

3.Motivation, leadership, and training

4. High and low KPI´s

• Performance metrics should point us precisely to what we need to improve currently in our maintenance process.

• That is, they should trigger a control action. Subsequently they should confirm and measure the extent to which the control action had the desired

effect.

4. High level KPI´s

High level (lagging) KPIs : provide, at various levels of granularity, such measures as:1. MTTF, MTTR, Availability2. Costs, and3. Yield

Low level KPI´s

Low level (leading) KPIs : should measure such indicators as:1. RCM knowledge added,

a. Standard deviation in remaining useful life estimationb. The influence of current CBM variables as reported by

the PHM shape parameter•The number of links between RCM knowledge and work orders,•The number of RA performed•CBM performance:

It is the manager’s job to set low level objectives that:1.Employees can influence by the way they perform their duties, and that

2.Support the high level organizational targets.

The managers job

The results achieved

1. Better analysis (lower shape factor, lower standard deviation ) More confidence in making decisions

2. The maintenance personnel have now a method to register in a precise way the right information inside the W.O. system.

3. More Reliability Analysis

4. Develops, verifies, and continually improves optimal maintenance policies

5. Updates to the knowledge base

The results achieved

Improvement in the quality of the information required for RA:

Carbones del Cerrejón

Fleet 789CToday 90%

% of Satisfactory W.O

% of Satisfactory W.O

May 40%

July 70%

Carbones del Cerrejón

FLEET FUNCTIONS (F)

FUNCTIONAL FAILURES (FF)

No. FAILURE MODES (fm)

F FF FM F FF FM F FF FM F FF FM

Haul truck 789C 98 153 694 104 162 739 105 164 748 109 171 785L1350 128 171 651 129 173 664Hit EX3600R 160 234 1075 169 243 1201 170 245 1210 174 249 1257

Haul truck 320 146 193 929 146 193 934 147 195 943Haul truck 240 77 113 466 78 114 468 111 165 692 113 171 723

FOLLOW UP OF STATISTICS IN RCMCostLRCM

1 2 3 4

Updates in the RCM knowledge base:

The results achieved

Summary

1. Use the language of RCM to guarantee the right information from the work order system (CMMS)

2. Add the condition monitoring (CBM) data

3. Apply Reliability Analysis to generate optimal DMs.

Age data (CMMS)CBM data Cost data

Reliability Analysis

(RA)

Optimal decision models

High availability

Low cost

More information

www.livingreliability.com

Managing LRCMLRCM KPIs

LRCM and HSEand

Other related topics

www.livingreliability.comoscar.hoyos@livingreliability.com

Thank you for your attention

Do you have any questions?

Questions ?