Institute of Transportation Systems > OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 1 OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE German Aerospace Center – Institute of Transportation Systems Katja Beck, Bärbel Jäger, Karsten Lemmer

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

Institute of Transportation Systems OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 3 Life Cycle Costs – Maintenance Strategy LCC – sum over all costs generated in the life phases of a product (DIN EN ) Maintenance cost determined mainly by Number of CM and PM cases Duration Manpower needed Maintenance Strategy CM – corrective maintenance PM – preventive maintenance

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

Institute of Transportation Systems OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 5 Time dependent maintenance German Railways Track components maintained dependent on load figure Load figure = Number of Trains x Total Tons x per week 0-35 low traffic volume normal traffic volume >600 high traffic volume Load category: Fix preventive maintenance interval + Easy to plan - Not cost efficient

Institute of Transportation Systems OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 6 Points Railway infrastructure element Ensuring system flexibility Maintenance based on Time Condition (use of point diagnosis systems) Wearout highly load-dependent

Institute of Transportation Systems OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 7 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 - Total costs for PM - Costs per PM case - Number of PM cases CM – corrective maintenance PM – preventive maintenance

Institute of Transportation Systems OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 8 Simulative Evaluations Railway operation simulation (e.g. RailSys  ) Number of trains Weight of trains Load figure = Number of Trains x Total Tons x 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 = Number of Trains Total Tons

Institute of Transportation Systems OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 9 Time-dependent vs. load-dependent maintenance LF = Load category LF = 36 Number of Trains (500 tons) per day = 39 LF = 600Number of Trains (500 tons) per day = 158 Scheduled Maintenance after 2 months (accordant to guide line)  2379 < Number of trains < low traffic volume normal traffic volume >600 high traffic volume

Institute of Transportation Systems OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 10 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 ScenarioNPV of PM costs Time-dependent - 2 months 100 % Load dependent - after 6000 vehicle crossings21 % Load dependent - after 9500 vehicle crossings 13 % NPV – Net Present Value PM – preventive maintenance

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

Institute of Transportation Systems > OPTIMISATION OF POINT LIFE CYCLE COSTS THROUGH LOAD-DEPENDENT MAINTENANCE > Slide 12 Thank you for your attention