Pontis Modeling Approach Overview

1. Pontis ModelingApproach Overview Transportation leadership you can trust. presented byCambridge Systematics, Inc. May 2004

2. Outline • What is Pontis? • Developing a preservationpolicy in Pontis • Simulating bridge conditions • New modeling features in Pontis • Improved deterioration model updating • Performance targeting for the long-term preservation model • Other improvements • Information resources

3. What is Pontis? • Windows-based bridge management system (BMS) with functionality for: • Recording bridge inventory and inspection data • Developing an optimal preservation policy • Simulating conditions and generating work candidates • Developing a bridge program • Used by over 45 agencies throughout the U.S. and abroad • Originally developed for the FHWA, now owned by AASHTO with Cambridge Systematics as AASHTO’s contactor • One component of AASHTO’s BRIDGEWare Suite

4. What is Pontis?Key Features of Pontis • Representation of a bridge as a set of structural elements • Recommendation of an optimal preservation policy • Extensive functionality for program simulation • Recommends preservation and improvements • Considers agency and user costs • Predicts a broad range of performance measures, with support from the FHWA NBI Translator • Support for an Oracle, Sybase or SQL Server Sybase • Extensive functionality for customization

5. What is Pontis?Bridge Management Process Supported by Pontis Import/ExportData ReviewBridgeData InspectBridges DevelopPreservationPolicy PerformNetworkAnalysis RefineResults DevelopBridgeProjects PerformProjects Source: NHI Training Course 134056A ,Pontis Bridge Management

6. Developing a Preservation Policy in PontisUse of Elements in Pontis • A bridge in Pontis is represented as a set of structural elements • AASHTO defines a set of Commonly Recognized (CoRe) elements, including descriptions of the element and condition states for each • Agencies may use the CoRe elements or define their own • For each element the user specifies • Feasible preservation actions for each state • Action costs and deterioration rates (expressed using transition probabilities) for each state • Bridges are inspected at the element level

7. Development of a Preservation Policy in PontisElement-Level Representation of a Bridge

8. Developing a Preservation Policy in PontisModeling Approach • Pontis recommends the optimal maintenance policy,or set of recommended actions for each state, foreach element-environment combination • Preservation models are built basedon expert opinion (elicitations)and inspection history • Each element ismodeled independently • The preservation modelsoptimize based on discountedlong-term agency costs usinga Markovian decision model

9. Simulating Bridge ConditionsPurpose of a Program Simulation • Pontis performs program simulations to • Determine current and future needs • Predict future performance • Develop work recommendations • Pontis can be used to determine • Conditions predicted based on a given budget • Budget needed to achieve a target • Given inspector and Pontis recommendations, an agency can use the system to develop its bridge plan

10. Simulating Bridge ConditionsInputs to a Program Simulation • Bridge inspection data • Preservation policy (generated by Pontis) • Functional improvement policy and costs • Budget • Agency business process rules • Planned projects • Additional simulation parameters

11. Simulating Bridge ConditionsSimulation Results • Predicted conditions (network and bridge-level) • Needs and predicted work • Benefits of meeting needs andperforming predicted work • Element conditions • Health index • NBI condition ratings • Sufficiency Rating • SD/FO status • Bridge-level workrecommendations

12. New Modeling FeaturesImproved Deterioration Model Updating • Deterioration models can be build based on expert opinion (elicitations) and inspection history • Recent improvements to the model updating process • Better algorithm for using inspection history in the update process • Option to specify whatbridges’ history to usefor model updating • Ability to rebuild historyor use prior history whenperforming successivemodel updates

13. New Modeling FeaturesPerformance Targeting in the Preservation Model • The long-term preservation model is used to specify optimal steady-state conditions • Steady-state conditions would result from following a specified policy over a period of many years • Pontis solves the long-term optimization model to determine what the annual cost would be to remain in the optimal steady-state condition • With Pontis 4.4 a user can add performance targets to the long-term optimization • Targets are specified in terms of Health Index • Provides long-term steady state funding requirements to achieve a specified performance target

14. New Modeling FeaturesPerformance Targeting Applications • Determining the cost of meeting agency-definedperformance targets • Quantifying thecosts of sub-optimalbridge conditions • Determining long-termminimum preservationfunding requirements • Improvedunderstanding ofthe Pontis-generatedpreservation policy

15. New Modeling FeaturesOther Improvements • Ability to specify bridges exempted from the agency’s functional improvement policy (e.g., historic bridges) • Program simulation horizon of up to 99 years • Flexibility for entering program simulation inputs in English or metric units • Capability for specifying when a bridge should be removed from the inventory at some future point

16. Information Resources • Web resources • FHWA: http://www.fhwa.dot.gov/infrastructure/asstmgmt/manag.htm • AASHTO: http://www.transportation.org/aashto/home.nsf/FrontPage • Pontis software support: http://aashtoware.camsys.com • Documentation • Pontis User’s Manual • Pontis Technical Manual • Referentia for Pontis Training CD