OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 1Institute of Transportation Systems >

OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH

LOAD-DEPENDENT MAINTENANCE

German Aerospace Center – Institute of Transportation Systems

Katja Beck, Bärbel Jäger, Karsten Lemmer

OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 2Institute of Transportation Systems

Motivation

1. Demand for more economic efficiency in the railway sector

3. Maintenance costs of infrastructure elements are cost drivers

2. More economic efficiency through a decrease in life cycle costs

OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 3Institute of Transportation Systems

Life Cycle Costs – Maintenance Strategy

LCC – sum over all costs generated in the life phases of a product (DIN EN 60300-3-3)

Maintenance cost determined mainly by

Number of CM and PM cases

Duration

Manpower needed

Formation cycle Market cycle

1.Concept & Definition

2.Design &

Development

3.Production

4.Installation /

Migration

5. Operation & Maintenance

6.Disposal & Recycling

Maintenance Strategy

CM – corrective maintenance

PM – preventive maintenance

OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 4Institute of Transportation Systems

Maintenance Strategy - German Railways

Decreasing the probability of failure and the number of corrective maintenance cases (EN 13306)

Preventive maintenance strategies

German Railway infrastructure maintained

Mainly time dependent

Condition-based through monitoring

Time dependent intervals

Condition based intervals

No preventive maintenance

OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 5Institute of Transportation Systems

Time dependent maintenance

German Railways

Track components maintained dependent on load figure

Load figure = Number of Trains x Total Tons x 10-6 per week

0-35 low traffic volume

36-600 normal traffic volume

>600 high traffic volume

Load category:

Fix preventive maintenance interval

+ Easy to plan

- Not cost efficient

OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 6Institute of Transportation Systems

Points

Railway infrastructure element

Ensuring system flexibility

Maintenance based on

Time

Condition (use of point diagnosis systems)

Wearout highly load-dependent

OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 7Institute of Transportation Systems

Idea: Load-dependent Maintenance

Why not use operation simulation information when determining the need for preventive maintenance work?

No falling below the wear-out limit

PMPMPM NcC

100%

Wear-out Stock

Time

Service Life

Maintenance Work

Wear-out limit

System Breakdown

Switch replacement

PMC - Total costs for PM

- Costs per PM case

- Number of PM cases

PMc

PMN

CM – corrective maintenance

PM – preventive maintenance

OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 8Institute of Transportation Systems

Simulative Evaluations

Railway operation simulation (e.g. RailSys)

Number of trains

Weight of trains

Load figure = Number of Trains x Total Tons x 10-6 per week

Example

Single way track

Ca. 50 passenger trains per day

Weight of 500 tons

LF = (50 x 7) x (50 x 500 x 7) x 10-6 = 61.25

Number of Trains

Total Tons

OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 9Institute of Transportation Systems

Time-dependent vs. load-dependent maintenance

LF = 61.25

Load category

LF = 36 Number of Trains (500 tons) per day = 39

LF = 600 Number of Trains (500 tons) per day = 158

Scheduled Maintenance after 2 months (accordant to guide line)

2379 < Number of trains < 9638

0-35 low traffic volume

36-600 normal traffic volume

>600 high traffic volume

OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 10Institute of Transportation Systems

Maintenance Cost Savings

Preventive maintenance cost savings for chosen example (67 points, 5 years period)

Relating to maintenance work after 2 months

Calculated with cost figures from the German Railways

Scenario NPV of PM costs

Time-dependent -

2 months 100 %

Load dependent -

after 6000 vehicle crossings 21 %

Load dependent -

after 9500 vehicle crossings 13 %NPV – Net Present Value

PM – preventive maintenance

OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 11Institute of Transportation Systems

Summary

Cost optimisation needed

Infrastructure maintenance costs as cost drivers

Use of train scheduling information instead of additional diagnosis equipment

Maintenance process flexibility needed

Load as a wearout factor

High saving potentials in point maintenance costs

Cost savings particularly high if LF is on the lower bound of the load category

OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 12Institute of Transportation Systems >

Thank you for your attention