Overview of presentation · Alexander Sinske, CTO GLS Consulting [email protected] Overview of...

Copyright 2015 - GLS Consulting (Pty) Ltd Printed with permission. 1

Alexander Sinske, CTO GLS [email protected]

Overview of presentationOverview of presentation

Investment planning: Water pipesPrinciples & DefinitionLikelihood of FailureConsequence of FailureRoll-up of resultsCase Study: Overstrand MunicipalityAsset management alignmentLong term investment planningConclusion

Investment planning: Water pipesPrinciples & DefinitionLikelihood of FailureConsequence of FailureRoll-up of resultsCase Study: Overstrand MunicipalityAsset management alignmentLong term investment planningConclusion

mailto:[email protected]


Investment planning: Water pipesInvestment planning: Water pipes

Input- CAPEX- Development planning- Planned replacement and upgrades- Condition assessment

Output- Failure incidents- OPEX- Interruption: Duration x No of consumers = SID - (Service Interruption Delay)- Water loss

Input- CAPEX- Development planning- Planned replacement and upgrades- Condition assessment

Output- Failure incidents- OPEX- Interruption: Duration x No of consumers = SID - (Service Interruption Delay)- Water loss

PrinciplesPrinciples

Pipe replacement prioritization (PRP)Probability of Failure (PF)Consequence (C)PF x C = RISK (in monetary terms)Intervention: Replacement / Refurbishment reduces- Risk- OPEX- SID- Water loss

Pipe replacement prioritization (PRP)Probability of Failure (PF)Consequence (C)PF x C = RISK (in monetary terms)Intervention: Replacement / Refurbishment reduces- Risk- OPEX- SID- Water loss


PRP: DefinitionPRP: Definition

��= � ��

��

��= � ��

��

��= ��

PRP: Likelihood of failure (LF)PRP: Likelihood of failure (LF)

Typical Contributing Factors- Nominal diameter- Reserve water pressure ratio- Catalogue remaining useful life- Required (forced) upgrade- High failure frequency- DMA zone leakage volume (where available)- Undesired pipe material (e.g. AC)- Assessed Condition (where available)- Pipe material in combination with geology- High corrosion potential for steel pipes- High static-dynamic pressure range

Typical Contributing Factors- Nominal diameter- Reserve water pressure ratio- Catalogue remaining useful life- Required (forced) upgrade- High failure frequency- DMA zone leakage volume (where available)- Undesired pipe material (e.g. AC)- Assessed Condition (where available)- Pipe material in combination with geology- High corrosion potential for steel pipes- High static-dynamic pressure range


Rating of Likelihood of failure (e.g.)Rating of Likelihood of failure (e.g.)

Reserve Pressure Ratio = Reserve Pressure Ratio =

Property Criteria Rating(<=) (1..5)

Reserve Pressure Ratio 0.25 1




Reserve Pressure Ratio >0.99 5

Rating of Likelihood of failure (e.g.)Rating of Likelihood of failure (e.g.)

Required Upgrade (master plan item)Required Upgrade (master plan item)


Likelihood of failure – failure frequencyLikelihood of failure – failure frequency

Likelihood of failure – typical weightingLikelihood of failure – typical weighting


PRP: Consequence of failure (CF)PRP: Consequence of failure (CF)

Typical Contributing Factors- High damage cost to consumer due to water

pressure- High damage cost to consumer due to flow- High repair cost based on pipe cost function- Flooding due to steep geography - Strategic location (e.g. CBD, HOS, IND)- Lack of network redundancy

Typical Contributing Factors- High damage cost to consumer due to water

pressure- High damage cost to consumer due to flow- High repair cost based on pipe cost function- Flooding due to steep geography - Strategic location (e.g. CBD, HOS, IND)- Lack of network redundancy

Rating of Consequence of failure (e.g.)Rating of Consequence of failure (e.g.)

High repair cost (due to location)High repair cost (due to location)


Consequence of failure – typical weightingConsequence of failure – typical weighting

LF – typical final factor visualizationLF – typical final factor visualization


CF – typical final factor visualizationCF – typical final factor visualization

PRP – typical final factor visualizationPRP – typical final factor visualization


PRP: Roll-up of resultsPRP: Roll-up of results

To facilitate interpretation of PRP results, roll-up of results to areas is supported by- Political region- Roll-up area

Roll-up areas typically consist of - Bulk systems for Bulk Pipes- Suburbs for Network Pipes- Street block polygons for Network Pipes

The pipe length weighted average PRP is calculated for each areaA ranking index is calculated (PRP%)

To facilitate interpretation of PRP results, roll-up of results to areas is supported by- Political region- Roll-up area

Roll-up areas typically consist of - Bulk systems for Bulk Pipes- Suburbs for Network Pipes- Street block polygons for Network Pipes

The pipe length weighted average PRP is calculated for each areaA ranking index is calculated (PRP%)

Rolled-up PRP – visualizationRolled-up PRP – visualization


Case Study: Overstrand MunicipalityCase Study: Overstrand Municipality

PRP Reports- 2010- 2012- 2014

PRP Reports- 2010- 2012- 2014

Overstrand – failure frequency analysisOverstrand – failure frequency analysis

Logged pipe failure important source of information to identify where pipe failures are likely to occur in futurePipe sections might have been replaced, but underlying reason for failure might not have been resolved Future failures are likely to occur again in adjacent sections until total replacement of street block or areas has been done

Logged pipe failure important source of information to identify where pipe failures are likely to occur in futurePipe sections might have been replaced, but underlying reason for failure might not have been resolved Future failures are likely to occur again in adjacent sections until total replacement of street block or areas has been done


Overstrand – failure frequency analysisOverstrand – failure frequency analysis

Geo-coding process followed to map incidents to modelled pipesTypical values recorded between 0 and 29 incidents/km/aFailures where the correlated pipe was replaced within the same year or after the failures was recorded, were excluded. This assumes that the reason for the failure related to the old pipe was resolved

Geo-coding process followed to map incidents to modelled pipesTypical values recorded between 0 and 29 incidents/km/aFailures where the correlated pipe was replaced within the same year or after the failures was recorded, were excluded. This assumes that the reason for the failure related to the old pipe was resolved

Overstrand PRP – visualizationOverstrand PRP – visualization

PRP values shown for pipes on aerial mapPRP values shown for pipes on aerial map


Overstrand PRP – visualization detailOverstrand PRP – visualization detail

Detail PRP breakdown shown for pipes on cadastral & contoursDetail PRP breakdown shown for pipes on cadastral & contours

Overstrand PRP – typical final map Overstrand PRP – typical final map

Top 200 pipes which have 3 or more bursts recordedTop 200 pipes which have 3 or more bursts recorded


First successes: reduction in burstsFirst successes: reduction in bursts

Reduction in pipe bursts recorded in Pringle Bay since 2010 replacementsReduction in pipe bursts recorded in Pringle Bay since 2010 replacements

Analysis of post-PRP replacement areasAnalysis of post-PRP replacement areas

Betty’s Bay 8 for example had highest PRP rankingBetty’s Bay 8 for example had highest PRP ranking

Length-Weighted Meter Pipe Pipe Burst Pipe Burst Pipe Replace CostAreaName PRP Replaced Replacement Count per a/km Count per a/km (2014)

(2012) Pipe Year before Replacement after ReplacementBetty's Bay 1 0.239 415 2013 3.787 0.000 207 998.00R Betty's Bay 2 0.216 570 2013 3.509 0.000 285 684.00R Betty's Bay 3 0.252 1 860 2013 4.839 0.000 1 500 408.00R Betty's Bay 4 0.265 725 2013 4.729 0.000 363 370.00R Betty's Bay 5 0.186 1 780 2013 0.321 0.000 927 017.00R Betty's Bay 6 0.153 420 2012 5.159 0.000 219 324.00R Betty's Bay 7 0.174 185 2012 7.207 0.000 92 722.00R Betty's Bay 8 0.451 495 2012 9.764 1.010 248 094.00R Betty's Bay 9 0.192 650 2012 3.590 0.000 325 780.00R Kleinmond 1 0.222 2 105 2013 1.493 0.000 1 055 026.00R Hermanus 1 0.203 3 395 2012 0.589 0.147 1 742 146.00R Stanford 1 0.220 595 2013 0.240 0.000 298 214.00R Stanford 2 0.250 385 2013 0.000 0.000 329 329.00R Pearly Beach 1 0.158 240 2012 0.000 0.000 120 288.00R Pearly Beach 2 0.142 170 2012 0.000 0.000 85 204.00R Pearly Beach 3 0.172 345 2012 0.725 0.000 172 914.00R Pearly Beach 4 0.174 1 015 2012 0.493 0.000 522 438.00R Pearly Beach 5 0.186 2 050 2012 1.098 0.000 1 027 460.00R TOTAL 0.214 17 400 2012-2013 2.215 0.074 9 523 416.00R



Replacements areas post PRP implementation (Betty’s Bay)Replacements areas post PRP implementation (Betty’s Bay)


Length-weighted replacement priority (PRP) before replacementLength-weighted replacement priority (PRP) before replacement



Projected replacement cost (2014 pricing)Adjacent areas considered also for replacementProjected replacement cost (2014 pricing)Adjacent areas considered also for replacement


Replace Cost vs Repair Cost break-even point (years) @ R25 000 per typical burstReplace Cost vs Repair Cost break-even point (years) @ R25 000 per typical burst


Asset management alignmentAsset management alignment

A further step is to provide an aligned technical approach with Asset Management Principles and provide an absolute measure of need of replacement, not just rankingResult can be used to compare different models with each otherFrom existing PRP results, Failure Modes are analysed independently of each other to determine the final corrected Remaining Useful Life (RUL)

A further step is to provide an aligned technical approach with Asset Management Principles and provide an absolute measure of need of replacement, not just rankingResult can be used to compare different models with each otherFrom existing PRP results, Failure Modes are analysed independently of each other to determine the final corrected Remaining Useful Life (RUL)

Asset management alignmentAsset management alignment

The independent Criticality Grade for a pipe is determined from the existing PRP data.Risk Exposure (RE) can for example be defined as Criticality Grade x (RULmax-RUL)(of the worst failure mode)Roll-up of RE and RUL also possible to street blocks

The independent Criticality Grade for a pipe is determined from the existing PRP data.Risk Exposure (RE) can for example be defined as Criticality Grade x (RULmax-RUL)(of the worst failure mode)Roll-up of RE and RUL also possible to street blocks


RUL correction algorithmRUL correction algorithm

Verification against condition-based RUL bandsVerification against condition-based RUL bands


Long term investment planningLong term investment planning

Focusses on simulating annual replacements highlighting spending a PRP budget efficientlyMinimize SID: Non-service minutes due to replacements or repairs per total number of connections in areaMinimize predicted number of theoretical failures (OPEX)Optimize CAPEX for condition assessment

Focusses on simulating annual replacements highlighting spending a PRP budget efficientlyMinimize SID: Non-service minutes due to replacements or repairs per total number of connections in areaMinimize predicted number of theoretical failures (OPEX)Optimize CAPEX for condition assessment

Typical outcome: multi-year simulationTypical outcome: multi-year simulation



Conclusion & RecommendationsConclusion & Recommendations

PRP provides key input to engineering inspection, refurbishment and replacement processes.PRP should be used for inspection or guide for replacement, not blindly implemented. Pressure management should also be considered in high pressure areas. PRP programme implemented at Overstrandshowing success. Need longer failure record.Asset management alignment as well as long term investment planning provides valuable future extensions to PRP

PRP provides key input to engineering inspection, refurbishment and replacement processes.PRP should be used for inspection or guide for replacement, not blindly implemented. Pressure management should also be considered in high pressure areas. PRP programme implemented at Overstrandshowing success. Need longer failure record.Asset management alignment as well as long term investment planning provides valuable future extensions to PRP


- Thank You -- Thank You -

Overview of presentation · Alexander Sinske, CTO GLS Consulting [email protected] Overview of...

Documents

Transcript of Overview of presentation · Alexander Sinske, CTO GLS Consulting [email protected] Overview of...