(c) 2013 by Edy Suwondo 1

Maintenance ConceptDaftar Pertanyaan yang harus dijawab

Apa beda perawatan dengan modifikasi? Apa yang dimaksud dengan perawatan pencegahan

(preventive maintenance), dan perawatan korektif (corrective maintenance)? Apa batasnya?

Apa yang dimaksud dengan degradasi gradual? Apa bentuk pdf yang berkaitan? Apa strategi perawatan yang cocok dan mengapa demikian? Pertanyaan yang sama untuk degradasi time-delayed dan degradasi mendadak (sudden).

Apa dasar condition progress known?

Maintenance ConceptDefinition of Maintenance

All activities subjected to technical systemsto keep the condition (Preventive)

or to bring to the condition (Corrective)which is required to fulfill specified functions

Preventive Maintenance: Actions before functional failureCorrective Maintenance: Actions after functional failureCriterion: Functional failure definitionRecording: Down time, Material Cost, Man hoursJudgment of Effectiveness of Preventive maintenance task

(c) 2013 by Edy Suwondo 2

Maintenance and Non Maintenance Activities

NON MAINTENANCE ACTIVITIES:Operational ActivitiesModification (Operational, Technical)

Perf

orm

ance

leve

l/co

nditi

on/

res

ista

nce

to fai

lure

Initial Condition (Design)

Functional failure condition

Time

MAINTENANCE

MODIFICATION

Cycle, Calendar Time, Operating Hours

Failure Degradation Types

A B C

Time

Perf

orm

ance

le

vel/

cond

ition

/ res

ista

nce

to f

ailu

re

Initial Condition

Potential failure condition

Functional failure condition

DEGRADATION TYPESA: GRADUAL DEGRADATION TYPEB: TIME DELAYED DEGRADATION TYPEC: SUDDEN DEGRADATION TYPE

(c) 2013 by Edy Suwondo 3

Time

Con

ditio

nInitial Condition

Functional failure condition

Periodic Interval I

MTBF I MTBF

(t)

PROGRESS OF CONDITION KNOWNGRADUAL DEGRADATION TYPESMALL SPREAD OF CONDITION PROGRESSSIGNIFICANT GROWTH OF HAZARD/FAILURE RATE

HARD TIME

Periodic Maintenance

Time

Con

ditio

n

Initial Condition

Functional failure condition

Interval I

MTBF I

(c) 2013 by Edy Suwondo 4

Maintenance PoliciesPreventive Maintenance Policies1. PERIODIC POLICY:

Hard Time (HT)Condition progress as function of time known

2. CONDITION BASED POLICYOn Condition (OC)Condition progress as function of time unknown

Corrective Maintenance PolicyCondition Monitoring (CM)

Relation among Degradation Type, Hazard Rate and Maintenance Policy

Degradation Type Failure RateBasic

Maintenance Policy

A. Gradual

1. Small Spread Significant Growth Periodic Maintenance

2. Large Spread Non Significant Growth Condition Based Maint.

B. Time Delayed Non Significant Growth Condition Based Maint.

C. Sudden Constant Corrective Maintenance

(c) 2013 by Edy Suwondo 5

Basic Maintenance PoliciesMaintenance

PreventiveMaintenance

CorrectiveMaintenance

Condition BasedMaintenance

PeriodicMaintenance

HARD TIME

PREVENT

CONDITION MONITORING

REMEDY

ON-CONDITION

ANTICIPATE