Transcript CME2300 Financial Engineering

Onderhouden of Nieuwbouwen
Prof Han Vrijling/ir drs Jules Verlaan
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Contents
• Theory of Maintenance
• Maintenance in Port Engineering
• Life cycle cost
• Economic life cycle approach
• Life cycle approach to systems
• Conclusions
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Mechanical Engineering
Maintenance
• Inspection
• Repair
• Strategies
• Corrective
• Failure
• Preventive
• Inspection
•
•
Repair
Repair
Working hours
State
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Conditional
failure rate
New
Old
Time
“bath tub” curve
based on the observation of many actual failures
conditional failure rate
h(t) = f(t)/{1- F(t)}
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Hydraulic and Port Engineering
• Corrective maintenance
• Is not advised in view of the risk involved: partial closure of the
port
• Preventive maintenance
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•
•
•
Time based
Use based
Load based
Resistance based
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Conditional failure rate
Hazard rate
• Pr {R<S} in year n, given survival to n
• No deterioration of R
Sea dike
Height dike
Stays the same
If “it” works
failure rate is dropping
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Are good deterioration models available?
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Dike settlement
• S.L.S.
• U.L.S.
h0-A.Int = h(t)
H(t)-HW
overtopping
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Channel siltation
• S.L.S.
• U.L.S.
d0 - zi = d(t)
d(t) - dship
random walk
grounding
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Value of inspection
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The life cycle cost problem
Minimize total cost:
•Investment
•Inspection
•Repair
•Risk = pfailure x Consequence
Ctotal = Cinvest + Cinsp + Crepair + pfail x C
Minimize PV{Ctotal}
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Capital dredging
Echo sounding
Maintenance d.
Pr(grounding)
→
→
→
→
Investing
Inspection
Repair
Risk

Dredging cycle
2-5 years
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The economic life cycle problem
More alternatives:
1. Repair old structure
2. Build new structure
New structure
Wages
Fuel
Material
Inspection
Repair
Depreciation
Interest
Insurance (risk)
Integral cost
new
Technical lifetime
Old structure
Wages
Fuel
Material
Inspection
Repair
<
Variable cost
old
Minimize total cost!
Economic lifetime < Technical lifetime
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Economic life cycle approach
Economic point of view:
A Revenue
B Cost
Not only costs
New structure
Old structure
Revenuenew
Revenueold
Integral costnew
Variable costold
Profitnew
> Profitold
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Economic life cycle approach
Planned economic life time
>
Real economic life time
-Loss of investment
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•
•
•
Intensify use
Move assets to other location
Reassemble assets for other function
Built in flexibility
Most promising
Underlying assumption:
Technical lifetime > Economic lifetime
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Organization
port & traffic
Economic life cycle approach of the port system
-
deep water channel
Entrance channel
Breakwaters
Port layout + handling
Quays and jetties
(un)Loading equipment
Inland transport
Focus is on
Limiting factor!
Revenue orientation
Changes in relative costs
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•
Cause of value
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Conclusions
Maintenance theory is an aid to life cycle management. Focus
on risk of failure
Include the renewal option in life cycle cost management
New opportunities are more important than optimal
maintenance
Optimize the port system spending on limiting factors
Do some dismal thinking to find the bright ideas
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