C E
1 Simple Cause and effect
C2
C1E
C
EC E
C5 Causal Loop
Figure 1.1 Cause and effect
E C
2 Multiple Causes
EC E CE C
C E
C
E2
E1
3 Multiple Effects
4 Causal Chain
In complex systems all of thesecan occur simultaneously, whichis why “root cause analysis” isoften difficult to do.
Also, the “root cause” often liesOutside of your system. What doyou do then?
Dr H A Yuniarto Industrial Engineering - UGM
Lost Production
Bearings not
Connectivityvia a specificcausal loop
Equipment Malfunction
No moneyavailable
No
Parallel causal loopseach connected to
all other loops
Untrained Technician
Bearings notlubricated
No“lubrication”
Training Other Training
inadequate
Technicians also not not trained in othermaintenance tasks
OtherMaintenance
not done
Figure 1.2 - Connectivity and causal loops
Dr H A Yuniarto Industrial Engineering - UGM
Level 1 – Individuals components maintain geometric shape
Level 2 – Component maintain correct relationships w ithin an item
Level 3 – Items maintain correct relationship to eac h other
Pump/ motorAssembly``
Example of knock-on effects
Transmits misalignmentor vibration
Figure 1.3 Geometric integrity
Ball bearing�Balls�Races�Gage
Pump�Bearings�Rotor�Stator
Assembly``Wear causes
misalignment or vibration
Misalignmentgenerates
Uneven load
Uneven Load causes wear
Level 1
Level 2
Level 3
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TransformationProcessInputs Outputs
Standards &Specifications
Procedures &Instructions
Environment
Equipmentand services
Knowledge& skill
Figure 1.5 - The Generic Process Model (also known as the “Quality” model)
Dr H A Yuniarto Industrial Engineering - UGM
Process Output
Standards•Maintenance Objectives•Technical Specifications•Welding procedures•Safety Standards
Inputs•Financing•Information•Materials
Methods•Job Methods•Task Schedules•Safety plans•Quality Plans
Maintainingthe plant
Work completedto specification•Materials
•Energy
Hardware•Mobile Plant•Cranes & hoists•Hand tools•Electrical tools
Knowledge & skill�Management�Planning�Supervision�Craft skills
the plant
Figure 1.6 - A “Maintenance” Process Model
to specification
Dr H A Yuniarto Industrial Engineering - UGM
Perform
TaskOUTPUTS
Measure
Money
Machines
Materials
Manpower
I
N
P
U
T
S
Methods
Change input(s)
StandardsCompare
with
Accept
Reject
Release (becomes input into a
subsequent process )
Figure 1.7 - A generic process control model
Change input(s)
Dr H A Yuniarto Industrial Engineering - UGM
Acceptable weld
Radiograph
Cost of weld
TIG Weld Machine
Weld electrodes
Qualified Welder
Weld procedure
WeldButt
Change input(s)
Compare with
Accept
Reject
WeldingStandards
• Penetration• Porosity
Release for assembly (subsequent process)
Figure 2.8 A “welding” process control model
Change input(s)
Dr H A Yuniarto Industrial Engineering - UGM
Maintenance Management
Establishesand controls
Money
Manpower
Methods
Materials
Machines
INPUTS
Measureoutputs O
UTPUTS
Maintenance Function
Provides ManpowerWorkMaterials
EnvironmentalDisturbances
InfluenceDecisions
Influences System butSystem cannot control
Maintenance process
Figure 2.8 - Maintenance management control process
MachinesS
Reporting process
TransmitData
ComparisonStandardsAcceptable
Continue
Not acceptable
Change
Generates
S
RCI
Improvement
Reportsresults
Proactive Change
Dr H A Yuniarto Industrial Engineering - UGM
Money
Manpower
Methods
Machines
Structure
Characteristics influence structure & function
Cause & effect
Feedback loops Emergent Properties
Connectivity
Characteristics FunctionsManagingSpecifyingPlanning SchedulingExecutingReporting
Complexity
Figure 2.1 – System structure, function and characteristics
Materials
Machines ReportingImproving Feed-forward
Functions generate the characteristics
Structure influences the functions
Environment Influences
Dr H A Yuniarto Industrial Engineering - UGM
PlanningMaintenance Strategy
~ Workload
~ Collect
Maintenance Policy
Establishesobjectives for
INPUTS
EnvironmentalDisturbances
Forcedchange(By agreement with
other departments)
OUTPUT
Manpower
(3rd order)
Measureoutputs
Measureinputs
MoneyManpowerMethodsMaterialsMachines
Review
~Production pressure
~ KPIs~ Standards
~ Collate
~ Schedule
Work
Effectiveness
Materials
~Plant Modification~Business performance~Shortage of resources
~Utilisation~Performance
~Completion~Quality
~Stock cost~% Turnover
~ Plan
Efficiency
~ Procedures
Execution
Allocatework
Report
~ Prepare~ Perform~ Compare
InfluenceSystem butSystem cannotcontrol
Gatekeeping
~Legislation
Figure 2.3 Maintenance System process model
S
Comparison Standards(Performance Analysis)
Reports resultsGenerates
TS
Feedback results to promote future improvement
Corrective actionIf required, perform root cause investigation
ReportingSystem
Feedbackdata via
Review
Improvement
acceptable
Co
ntin
ue
Tolerate reducedPerformance (onlyas a last resort)
and
(2nd order)
(1st order)If not tostandard
Change
Recommend Change (4th order) – feed forward proposals and action plans
~ StandardsEffectiveness
~Innovation~Design out~New Techniques~New technologies
~% Turnover
Reliability Production.
unacceptable
Report
or
Dr H A Yuniarto Industrial Engineering - UGM
Control is exercised over the maintenance functionby asking the following six critical questions
�Are we carrying out the maintenance strategy?
Keep asking thequestions becausesituations change
�Is the maintenance effective? (plant output/ quality achieved? – if not ,why not?
(are we working to “the plan”?– if not ,why not?�Are we working efficiently?
(achieving the standards set ?– if not ,why not?
�Is the maintenance strategy appropriate? (does it serve current needs? – if not ,why not?
�Is the maintenance efficacious?
Measure& report
Figure 2.6 -Principle of Maintenance Control
Detect anydeviation
Take actionto correct
situations change
(work performed within budget? – if not ,why not?�What is the total cost of maintenance?
�Is the maintenance efficacious? (does it serve the wider system? – if not ,why not?
Dr H A Yuniarto Industrial Engineering - UGM
Critical Questions
� What is the capability of the maintenance organisation?
� What is the capability of the system?
� What is the relationship between system and organisation?
Organisations and systems don’t always fit together
Dr H A Yuniarto Industrial Engineering - UGM
Structure and function
Structure = “What it is” = the maintenance organisation
Function = “What it does” = the maintenance workload
Methodology= “How it does it” = the maintenance system
Organisation SystemWorkload
Workload effectiveness is influenced by organisation and system
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Organisation and system aligned
Manpower Methods
�Up-to-date procedures�Competent people�Clear R & Rs�Flat structure
�Reliable processes�Integrated processes �Good communication�Simple as possible
Organisation System
The degree of misalignment will determine the amount ofdifficulty the people will have
Features Features
Organisation and system misaligned
ManpowerMethods
�Unreliable processes�Disjointed processes�Poor communication�Overcomplicated
�Out-of-date procedures�Incompetent people�Vague R & Rs �Tall structure
Figure 3.1 - Fit between system and organisation
OrganisationSystem
difficulty the people will haveOperating the system
Features
Features
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00
00
Angularmisalignment
Over-machined flange (too thin)
Incorrect ordamaged gasket
Badly fittedgasket
Incorrectcold gap
Distortedflange
Figure 3.2 Standards: some common reasons for flange leaks
�Wrong studs and nuts used�Worn studs and nuts used�Studs Over-tightened�Studs Under-tightened�Wrong tightening technique�Wrong tightening sequence
Radialmisalignment
Axial misalignmentof mating flanges
Scratches onflange face
Pitting onFlange face
Dr H A Yuniarto Industrial Engineering - UGM
AptitudePhysical and/ ormental ability
Attitude-Limiting beliefs-Willingness
Human factors
Organisational factors
What the person possesses
What the system provides
Training-Relevant to the plant-Competently taught
PracticeSufficient forskill retention
SupportSystem must empower the individualand not prevent him from working
Figure 3.4 - Competence model
(Studies have indicated that many performance problems are caused by shortcomings in job structure and definition)
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