Scottish Water Assessment of Risk. Using Non-network modelling Interruptions to Supply Project

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Kenneth Porter
5 years ago
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1 Scottish Water Assessment of Risk Using Non-network modelling Interruptions to Supply Project

2 Base Risk Model Work on-going to create improved Base Risk Model. - Likelihood Element developed by Robert Murray improved through Burst Data project - Consequence Element work Completed by AECOM - Base Risk is then created and the effects of ITS project work monitored against base risk (Pioneering) Current Base Risk Model Corporate Likehood Corporate Consequence (20% Accuracy) Proposed Base Risk Model Corporate Likehood + Cost of Risk Improved Consequence Model (60% to 80% Accuracy) Residual Risk Model Corporate Likehood Actual Events Improved Consequence Model Cost of Risk Measurable Overall Output Risk Reduction v s Cost Base Model Residual Model Additional Outputs Target Investment in Areas Critical Valve Information Response information warehouse Contingency Planning Capex and Opex Planned Preventive Maintaince MST on Assets Response Time Improvement Target areas for improved alarms and monitoring Instant availblity of number of properties affected Determine sections of infrastructure with which has by-passes Improved Response times to large incidents Trigger Properties Improved estimates of repair times Contingency Planning Creation of Schematics Pressure At Boundarys

3 CONSEQUENCE

4 Rules we have used to create Consequence Analysis Material CI - Cast RailProx 20 FailureEventAwareness_URBAN 1 RailProx_AT 8 FailureEventAwareness_RURAL Repair Time_Medium 1 Repair SlopeProx Time_High 10 FailureEventAwareness_GRASSLAND Grade ITS Grade GRADE 1.5 SCORE SlopeProx_AT Grade Grade 2 DepotTravelTime (km/h) 30 PylonProx 10 LocateFailure_URBAN 1 PylonProx_AT 4 LocateFailure_RURAL Very High_High 1 TreesProx 12 5 LocateFailure_GRASSLAND 1.5 TreesProx_AT 2 TimeToIsolatePerValvesToClose 0.5 MarshProx 5 TimeToIsolatePerDistanceToValvesToClose Very High_Medium 0.5 MarshProx_AT 11 2 TimeForRepair-(0mm- 100mm)NoConstructionDifficultiesCOLLARREPAI Very High_Low 1 StructureProx 10 5 R Directly Directly TimeForRepair-(100mm- Directly Directly 2 StructureProx_AT 3 300mm)NoConstructionDifficultiesCOLLARREPAI Affected Affected Affected High_High Affected 9 TimeForRepair-(300mm- 3 Sensitive MajorRoadProx Sensitive mm)NoConstructionDifficultiesCOLLARREPAI Properties Properties TimeForRepair- Medium High_Medium Customers 8 Customers (500mm+)NoConstructionDifficultiesCOLLARREP 5 Low MajorRoadProx_AT Medium 4 AIR Consequence Consequence TimeForRepair-(0mm- < No High_Low Consequence > No 7 Consequence No 100mm)NoConstructionDifficultiesCUTOUTREPAI 2 < No TimeToRechargeMain_PerValvesToOpen < No 0.5 R TimeForRepair-(100mm- Medium_High TimeToRechargeMain_PerDistanceToValves mm)NoConstructionDifficultiesCUTOUTREPAI ToOpen TimeForRepair-(300mm- FlowRechargeRate-AppliedToVolumeOf mm)NoConstructionDifficultiesCUTOUTREPAI Medium_Medium Isolation 5 TimeForRepair- (500mm+)NoConstructionDifficultiesCUTOUTREP 8 AIR Medium_Low TimeToChlorinateand Sample 4 1 WaterProx 15 WaterProx_AT 6 Repair Time_Low Directly Affected Properties Low Consequence < No Repair Time_Very High Directly Affected Sensitive Customers High Consequence > Low_High 3 Low_Medium 2 Low_Low 1

5 Consequence Analysis M

6 Consequence Analysis The analysis not only takes into consideration the pipes and back feeds but also the service reservoirs. It will change the time taken to take into consideration the storage time.

7 Consequence Analysis

8 LIKELIHOOD

Steel Spun_Iron PVC PS_Con PE Other Miss Iron Dct_Iron Asb_Ce 0 0-10 10-20 20-30 30-40

9 Process used to Generate Likelihood Length Laid per 5 Year Period by Material Type % Overall Length Assets split into cohorts with the same characteristics e.g. age, diameter. Steel Spun_Iron PVC PS_Con PE Other Miss Iron Dct_Iron Asb_Ce Agegroup

10 Basic factors generated log(duration in Hours) = Characteristic Fitted Value Intercept ARM_DIAMETER_CLASS mm ARM_DIAMETER_CLASS mm ARM_DIAMETER_CLASS >152.4mm ARM_DIAMETER_CLASS MISSING ARM_MATERIAL Ductile Iron ARM_MATERIAL Iron ARM_MATERIAL Other ARM_MATERIAL PE ARM_MATERIAL PVC ARM_MATERIAL Spun Iron ARM_MATERIAL Steel ARM_MATERIAL Missing ARM_CONNECTIONS Missing ARM_AC_AGGRESSIVE Less Aggressive ARM_AC_AGGRESSIVE Moderately Aggressive ARM_FE_AGGRESSIVE Not Aggressive ARM_REGION North ARM_REGION South ARM_REGION West ARM_REGION Missing ARM_SURFACE_CODE Rural ARM_SURFACE_CODE Urban ARM_SURFACE_CODE Missing ARM_PROP_LEN_RATIO Missing log(rocof) = intercept + (β 1 x Characteristic 1) (β n x Characteristic n)

11 Accuracy of Likelihood Data We have approximately a 60% confidence of prediction based on a small sample

12 Top 100 Sites Across Scotland The top 100 is more representative of the key mains in Scotland This highlights the key 100 sites which will Hurt us the Most Central Belt has some of the worst sections

13 Glasgow 3D

14 ANY QUESTIONS

DISTRIBUTION, OPERATION and MAINTENANCE STRATEGY ASSET MANAGEMENT WORK INSTRUCTION ISOLATION OF A WATER NETWORK

DISTRIBUTION, OPERATION and MAINTENANCE STRATEGY ASSET MANAGEMENT WORK INSTRUCTION ISOLATION OF A WATER NETWORK Document Title: Work Instruction Isolation of a Water Network Document Reference: DOM-WN-WIN-00000302 Approved By: Asset Management Title: General Manager Record of Changes and Amendments Amendment No.