5 december 2011 Living Probabilistic Asset Management Dr.ir. J.A. van den Bogaard

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management25 december ,5  [-/vraag] 1,0  [-/vraag]

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management35 december 2011 From PSA to LPAM PSA proven, mature methodology in Nuclear and Petro-Chemical Industry, which is routinely applied PSA focuses on Safety while critical performance characteristics of infrastructure demands focus on RAMS aspects PAM extends the focus on safety to RAMS Systems and operations change over time need to be taken into account: –Physical changes in the design of a system –Changes in operating conditions –Improvements in the understanding of system behaviour in fault conditions –More system specific data become available Keeping the PAM useful over time it needs to be updated making it a Living PAM

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management45 december 2011 Definition LPAM A living PAM can be defined as a PAM analysis of a system, which is updated, if necessary, to reflect the current built and operational features and is documented in such a way that each aspect of the model can be directly related to existing system information, operating conditions, system documentation or the analysts’ assumptions in the absence of such information.

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management55 december 2011 Characteristics of LPAM Framework for the process to obtain, maintain and optimize the reliability level Deming-circle Principle (plan-do-check-act) Complete mix of in-depth knowledge of technical systems, reliability analysis, maintenance Qualitative/Quantitative approach Reliability, Availability, Maintainability, Safety (RAMS)

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management65 december 2011 Scope of LPAM LPAM Organization Performance Analysis Contracts

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management75 december 2011 Implementation and operational process LPAM ACT Design Modifications Modify FT and Check Target Check Over-all and Component Performance PLAN Specify Modifications Instruct Contractors DO Implement Modifications Perform regular Maintenance INITIAL PHASE

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management85 december 2011 Phase 0: Initial Phase 1.System and function analysis 2.Defining RAMS requirements 3.Perform Qualitative and Quantitative Risk Analysis 4.Define As-Is situation 5.Define As-Wished situation 6.Define differences and plan activities 7.Translate to LPAM process Process description Defining necessary contral and operational organisation Define contracts (DBFM contractual aspects)

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management95 december Total probability of failure Probabilities of events result from fault tree analysis Fault tree 1Fault tree 2Fault tree 3 Fault tree … Fault tree n Event tree

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management105 december 2011 Topics in QRA Component and system reliability Common Cause Failure External Causes of Failure –Lightning –Fire –Internal flooding –Etc. Human reliability Software reliability

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management115 december 2011 Phase 1: Maintenance Planning Maintenance plan should include/respect all assumptions made in the QRA’s. Including: Maintenance strategies (CM, PM, CM) Inspection strategies/intervals Testing strategies/intervals Recovery and test procedures Repair times Stock policy

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management125 december 2011 Phase 2: Performing Maintenance In the DO phase modifications are implemented and regular maintenance is performed according to the maintenance plans. These activities consist of the execution of tests, inspections, revisions, repairs, replacements and the system modifications, as planned in the previous phase.

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management135 december 2011 Phase 3: Monitoring Process In the CHECK phase the overall system, components, maintenance en organizational performance of the system is monitored. Monitoring focuses on: –All failures, errors, disruptions and observations in process or system –All differences with respect to the assumptions in the risk analysis (repair times, inspection intervals, test intervals) –Effectiveness of all tests and inspections –Gathering information from tests and inspections for trend analysis of failure frequencies –Observations on human errors during maintenance and operations.

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management145 december 2011 Phase 4: Analyzing and Adjusting Risk Analyses In the ACT phase the probability of failure of the system is calculated with the new input from the check phase and is assured that the system still complies with the probability target. The final result, i.e. failure probability of the system, is compared with the target and if the target is met no additional design measures are necessary. But if the outcome does not comply with the target, the system has to be modified. Next to changing the hardware physically, also measures like reducing repair times, shortening test intervals or improve skills can be taken. These modifications will have to be evaluated again, until the probability target is met. This process constitutes a small loop within the ACT phase.

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management155 december 2011 Organization of the LPAM Process Important aspects: Implementation of LPAM is usually carried out by a project team After implementation the maintenance organisation becomes responsible for the quality and effectiveness of LPAM It is a mistakte to think that the organisation is in control after the initial phase Sufficient resources should be available Support from management is key to success Training and education programs should be available and implemented Other important issues in this phase are the role of (sub-)contractors, training of operation and training of maintenance activities and the interpretation of feedback from the maintenance activities the risk analyses.

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management165 december 2011 Documentation Results, conclusions and recommendations traced back to the design, operation and assumptions used in the analysis. The documentation needs to include details of the design and operation of the system and details of the analysis that form the basis for the models used in LPAM. The justification for the data used for initiating event frequencies, component failure probabilities, common cause failure probabilities, human error probabilities, etc. should be provided. All numerical values should be traceable, back to the source data or models.

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management175 december 2011 LPAM with respect to networks Application LPAM on infrastructural networks Complexity Criticality Costs Level of detail of analyses

Ministerie van Verkeer en Waterstaat Living Probabilistic Asset Management185 december 2011 Questions?