supporting road asset management with portfolio decision analysis

Helsinki University of Technology Systems Analysis Laboratory

INFORMS International, Hong Kong 2006

Supporting Road Asset Management Supporting Road Asset Management

with Portfolio Decision Analysiswith Portfolio Decision Analysis

Pekka Mild, Juuso Liesiö and Ahti SaloSystems Analysis Laboratory

Helsinki University of Technology

P.O. Box 1100, 02015 TKK, Finland

http://www.sal.tkk.fi

[email protected]


2INFORMS International, Hong Kong 2006

AgendaAgenda

Decision support challenges in road asset management

Bridge repair program selection with

Robust Portfolio Modeling (RPM)

Framework for unified road asset management

RPM-Decisions© software



Road Asset Management in FinlandRoad Asset Management in Finland

Central authority Finnish Road Administration (Finnra)– Control, planning and procurement of maintenance, repair and investments

– Research and development; processes, methods and tools

Estimated asset value 15 billion euros (19 billion USD)– Annual funding on maintenance and repair some 600 (750) million euros (USD)

Central administration and 9 road districts– National level: guidelines, tools and long term planning

– District level: Annual repair programs (pavements, bridges, etc.)

– One or few expert(s) per asset class responsible for programming



Decision Support Challenges at FinnraDecision Support Challenges at Finnra

Large and well recorded data sets– Extensive asset mass

– Advanced measurement systems

Multiple criteria– Subjective: e.g, road safety, customer satisfaction, asset value and life-cycle

management, environmental concerns

– Objective: several measurements and indicators serving as proxies for different

aspects of road condition, among others

Utilization of road asset management data– Driven by the recent developments in data production

– Trend towards outsourcing information services



Bridge Repair Program Selection - Bridge Repair Program Selection - Applying the RPM FrameworkApplying the RPM Framework

OPTIMOINTIMALLIN PISTEETKohdenumero ja nimi Ydinluku VPS KTI TM puut. KVL Suola Estets Hinta2109 Lavusjoen silta 1.00 5.00 1.65 4 2.6 1 2.6 500002218 Joroisvirran silta 1.00 5.00 5.00 2 5 5 2.6 1800002177 Hiidenlammin silta 1.00 3.58 3.24 2.5 2.6 1 1.8 200002217 Rautatieylikulkusilta 1.00 3.49 5.00 1.5 5 5 1.8 130000699 Parikkalan pohjoinen ylikulkusilta 1.00 3.23 3.01 1 5 5 1 160000857 Maijanaron alikulkukäytävä 1.00 1.90 1.49 1 5 5 1 10000763 Hurukselantien risteyssilta 1.00 2.27 2.33 1 3.4 5 1 280000723 Viipurintien risteyssilta 1.00 1.62 1.74 1 5 5 3.4 250000411 Korian ylikulkusilta 1.00 1.43 1.51 1.5 5 5 1.8 6000080 Suolammenojan silta 1.00 1.36 1.53 2 4.2 5 1.8 10000257 Villikkalan silta 0.81 1.97 1.96 5 1 1 1.8 200001743 Huuman silta II 0.76 1.64 1.53 1 5 5 1.8 1400002207 Visulahden myllyjoen silta 0.67 1.71 1.34 1 5 5 1 30000730 Mälkiän itäinen risteyssilta 0.63 1.33 1.58 1.5 5 5 1 1200002804 Raikuun kanavan silta 0.60 3.93 1.12 2.5 1 1 1 20000856 Ojaraitin alikulkukäytävä I 0.54 1.46 1.46 1 5 5 1 2000083 Lavin silta 0.53 1.57 1.26 2 4.2 5 1 200002703 Grahnin alikulkukäytävä 0.43 1.70 1.23 1 5 5 1 60000817 Petäjäsuon risteyssilta 0.39 1.52 1.37 1 5 5 1 50000266 Purhon silta 0.31 1.83 1.93 1 3.4 1 2.6 20000725 Mustolan silta 0.29 1.98 1.93 2 1.8 1 4.2 1900002189 Reitunjoen silta 0.24 1.90 1.63 3 1.8 1 1.8 10000849 Kotiharjun alikulkukäytävä 0.19 1.22 1.41 1 5 5 1 100002606 Haukivuoren pohjoinen ylikulkusilta 0.15 1.84 2.09 1.5 2.6 1 1 70000125 Telataipaleen silta 0.14 1.38 1.12 1 5 5 1.8 4000039 Luoman silta (Rokkilan silta) 0.12 1.62 1.82 3 1.8 1 1 10000606 Syväsalmen silta 0.05 1.53 1.58 3 1.8 1 2.6 20000608 Jalkosalmen silta 0.03 1.54 1.50 3 1.8 1 2.6 100002492 Rävykosken silta 0.02 1.52 1.90 2 1.8 1 2.6 20000556 Luotolan silta 0.00 1.74 1.26 3 1 1 1.8 10000661 Raikan silta 0.00 1.95 1.58 2 1 1 1.8 100002613 Pitkänpohjanlahden silta 0.00 1.27 1.16 1 4.2 5 2.6 20000738 Hyypiälän ylikulkusilta 0.00 1.72 1.79 1 3.4 1 1.8 900002549 Uitonsalmen silta 0.00 1.71 1.37 3 1 1 1 30000703 Tokkolan silta 0.00 1.82 1.70 2 1.8 1 1 10000870 Tiviän alikulkukäytävä 0.00 1.10 1.07 1 5 5 1 20000377 Sudensalmen silta 0.00 1.88 1.66 1 2.6 1 1.8 20000953 Sydänkylän silta 0.00 1.23 1.33 3.5 1 1 1.8 10000700 Kirjavalan ylikulkusilta 0.00 1.42 1.98 1.5 1 1 1 600002142 Latikkojoen silta 0.00 1.43 1.58 2.5 2.6 1 1.8 200002402 Tervajoen silta 0.00 1.40 1.17 3.5 1 1 1 10000464 Jokisilta 0.00 1.19 1.25 3.5 1.8 1 1 200001025 Hartunsalmen silta 0.00 1.18 1.09 3.5 1.8 1 2.6 2000095 Touksuon silta 0.00 1.83 1.18 2 2.6 1 2.6 20000418 Laukassalmen silta 0.00 1.54 1.35 1.5 2.6 1 1.8 10000420 Sillanmäenojan silta 0.00 1.20 1.07 1.5 2.6 1 1.8 10000

OPTIMOINTIMALLIN PISTEETKohdenumero ja nimi Ydinluku VPS KTI TM puut. KVL Suola Estets Hinta2109 Lavusjoen silta 1.00 5.00 1.65 4 2.6 1 2.6 500002218 Joroisvirran silta 1.00 5.00 5.00 2 5 5 2.6 1800002177 Hiidenlammin silta 1.00 3.58 3.24 2.5 2.6 1 1.8 200002217 Rautatieylikulkusilta 1.00 3.49 5.00 1.5 5 5 1.8 130000699 Parikkalan pohjoinen ylikulkusilta 1.00 3.23 3.01 1 5 5 1 160000857 Maijanaron alikulkukäytävä 1.00 1.90 1.49 1 5 5 1 10000763 Hurukselantien risteyssilta 1.00 2.27 2.33 1 3.4 5 1 280000723 Viipurintien risteyssilta 1.00 1.62 1.74 1 5 5 3.4 250000411 Korian ylikulkusilta 1.00 1.43 1.51 1.5 5 5 1.8 6000080 Suolammenojan silta 1.00 1.36 1.53 2 4.2 5 1.8 10000257 Villikkalan silta 0.81 1.97 1.96 5 1 1 1.8 200001743 Huuman silta II 0.76 1.64 1.53 1 5 5 1.8 1400002207 Visulahden myllyjoen silta 0.67 1.71 1.34 1 5 5 1 30000730 Mälkiän itäinen risteyssilta 0.63 1.33 1.58 1.5 5 5 1 1200002804 Raikuun kanavan silta 0.60 3.93 1.12 2.5 1 1 1 20000856 Ojaraitin alikulkukäytävä I 0.54 1.46 1.46 1 5 5 1 2000083 Lavin silta 0.53 1.57 1.26 2 4.2 5 1 200002703 Grahnin alikulkukäytävä 0.43 1.70 1.23 1 5 5 1 60000817 Petäjäsuon risteyssilta 0.39 1.52 1.37 1 5 5 1 50000266 Purhon silta 0.31 1.83 1.93 1 3.4 1 2.6 20000725 Mustolan silta 0.29 1.98 1.93 2 1.8 1 4.2 1900002189 Reitunjoen silta 0.24 1.90 1.63 3 1.8 1 1.8 10000849 Kotiharjun alikulkukäytävä 0.19 1.22 1.41 1 5 5 1 100002606 Haukivuoren pohjoinen ylikulkusilta 0.15 1.84 2.09 1.5 2.6 1 1 70000125 Telataipaleen silta 0.14 1.38 1.12 1 5 5 1.8 4000039 Luoman silta (Rokkilan silta) 0.12 1.62 1.82 3 1.8 1 1 10000606 Syväsalmen silta 0.05 1.53 1.58 3 1.8 1 2.6 20000608 Jalkosalmen silta 0.03 1.54 1.50 3 1.8 1 2.6 100002492 Rävykosken silta 0.02 1.52 1.90 2 1.8 1 2.6 20000556 Luotolan silta 0.00 1.74 1.26 3 1 1 1.8 10000661 Raikan silta 0.00 1.95 1.58 2 1 1 1.8 100002613 Pitkänpohjanlahden silta 0.00 1.27 1.16 1 4.2 5 2.6 20000738 Hyypiälän ylikulkusilta 0.00 1.72 1.79 1 3.4 1 1.8 900002549 Uitonsalmen silta 0.00 1.71 1.37 3 1 1 1 30000703 Tokkolan silta 0.00 1.82 1.70 2 1.8 1 1 10000870 Tiviän alikulkukäytävä 0.00 1.10 1.07 1 5 5 1 20000377 Sudensalmen silta 0.00 1.88 1.66 1 2.6 1 1.8 20000953 Sydänkylän silta 0.00 1.23 1.33 3.5 1 1 1.8 10000700 Kirjavalan ylikulkusilta 0.00 1.42 1.98 1.5 1 1 1 600002142 Latikkojoen silta 0.00 1.43 1.58 2.5 2.6 1 1.8 200002402 Tervajoen silta 0.00 1.40 1.17 3.5 1 1 1 10000464 Jokisilta 0.00 1.19 1.25 3.5 1.8 1 1 200001025 Hartunsalmen silta 0.00 1.18 1.09 3.5 1.8 1 2.6 2000095 Touksuon silta 0.00 1.83 1.18 2 2.6 1 2.6 20000418 Laukassalmen silta 0.00 1.54 1.35 1.5 2.6 1 1.8 10000420 Sillanmäenojan silta 0.00 1.20 1.07 1.5 2.6 1 1.8 10000



RPM-FrameworkRPM-Framework

Based on additive weighting model– Relatively simple and widely used

Incomplete information on weights and scores– Information set for feasible values of these parameters

Non-dominated portfolios and project-specific Core Indexes– Robust decision recommendations w.r.t. incomplete information

Framework paper– Liesiö, J., Mild, P., Salo, A., (2006). Preference Programming for Robust

Portfolio Modeling and Project Selection, EJOR (forthcoming, available on-line)



Non-dominated Portfolios and Core IndexNon-dominated Portfolios and Core Index

Non-dominated portfolios (NDP)– No other feasible portfolio gives higher

overall value with all feasible weights and

scores

Project’s Core Index (CI) conveys

the share of non-dominated

portfolios which contain the project – Core proj. are included in all NDP (CI=1)

– Exterior proj. not included in any (CI=0)

– Borderline proj. included in some (0<CI<1)

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Core Index AnalysisCore Index Analysis

Core Index is a relative measure of how well the project fits

into the portfolio; it accounts for:– Incomplete information on weights and scores

– Project’s cost and competing proposals

– Budget and other feasibility

constraints

Focus on classification– Correlations in project’s

scores lead to larger sets

of core and exterior projects

– Trade-offs not the primary focus

Hundreds of

projects

Multiple criteria

Portfolio-level

constraints

Borderline proj

→ focus

Exterior proj

→ reject

Core projects

→ accept

Computenon-dominated portfolios

Incomplete information



Bridge Repair Program DataBridge Repair Program Data

Total of 313 project prosals– Different bridges calling for repair

Full bridge stock from one road district– Equivalent analysis for another district, too, with analogous findings

Bridges in need of repair and rehabilitation – Backlog of bridges at end of their life-cycle

– Pre-emptive maintence not considered here

Repair program for next three years– “Priority bundle”, not scheluded year by year



Evaluation Criteria and CostsEvaluation Criteria and Costs

Six criteria indicating urgency for repair– Sum of Damages (“SumDam”)

– Repair Index (“RepInd”)

– Functional Deficiencies (“FunDef”)

– Average Daily Traffic (“ADTraf”)

– Road Salt usage (“RSalt”)

– Outward Appearance (“OutwApp”)

Value functions for measurement data (SumDam & RepInd), scoring tables based on recorded characteristics for the others– Scoring on a scale of 1-5, higher score indicating higher priority

Costs based on standardized condition-class and size



Incomplete Weight InformationIncomplete Weight Information

Interval statements and/or (incomplete) rank-orderings– Define a feasible weight set

Rank-ordering:

{SumDam,RepInd}

≥ {FunDef, ADTraf}

≥ {RSalt,OutwApp}

Sum of weights = 1

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Feasible weight set A feasible weight vector



Program ConstraintsProgram Constraints

Budget of 9,000,000€– Based on current annual funding allocated to bridge repairs

Program can contain maximum of 90 bridges– Proxy for limited availability of equipment and personnel etc.

Program must repair the total sum of damages

by minimum of 15,000 units– Merit pay threshold



Results (1/2)Results (1/2)

Found more than 10,000 non-dominated programs– Approximative algorithm based on random sampling of weighted

min-max norm and integer linear programming

– Programs’ total costs between 8.75 – 9.00 M€

– All programs contained 90 bridges → binding constraint

Proposals listed by their Core Index value– 39 core, 112 borderline and 162 exterior projects

– Tentative but not binding priority list

– Found practical and transparent by the programming managers

– Scores, costs and other characteristics displayed



Results (2/2)Results (2/2)

Consistent with the

earlier system– Condition factors are

still main determinants

of priority

– Use of road salt and the

traffic volume affect

explicitly → appreciated

Adds to current tools– Framework and results

deemed acceptable

BRIDEGES' SCORES

Bridge number and name Core Index DamSum RepInd FunDef ADTraf Rsalt OutwApp Cost

2109 Lavusjoen silta 1.00 5.00 1.65 4 2.6 1 2.6 50000

2218 Joroisvirran silta 1.00 5.00 5.00 2 5 5 2.6 180000

2217 Rautatieylikulkusilta 1.00 3.49 5.00 1.5 5 5 1.8 130000

763 Hurukselantien risteyssilta 1.00 2.27 2.33 1 3.4 5 1 280000

80 Suolammenojan silta 1.00 1.36 1.53 2 4.2 5 1.8 10000

257 Villikkalan silta 0.81 1.97 1.96 5 1 1 1.8 20000

1743 Huuman silta II 0.76 1.64 1.53 1 5 5 1.8 140000

730 Mälkiän itäinen risteyssilta 0.63 1.33 1.58 1.5 5 5 1 120000

2804 Raikuun kanavan silta 0.60 3.93 1.12 2.5 1 1 1 20000

856 Ojaraitin alikulkukäytävä I 0.54 1.46 1.46 1 5 5 1 20000

2703 Grahnin alikulkukäytävä 0.43 1.70 1.23 1 5 5 1 60000

817 Petäjäsuon risteyssilta 0.39 1.52 1.37 1 5 5 1 50000

725 Mustolan silta 0.29 1.98 1.93 2 1.8 1 4.2 190000

2189 Reitunjoen silta 0.24 1.90 1.63 3 1.8 1 1.8 10000

2606 Haukivuoren pohjoinen ylikulkusilta 0.15 1.84 2.09 1.5 2.6 1 1 70000

125 Telataipaleen silta 0.14 1.38 1.12 1 5 5 1.8 40000

608 Jalkosalmen silta 0.03 1.54 1.50 3 1.8 1 2.6 10000

556 Luotolan silta 0.00 1.74 1.26 3 1 1 1.8 10000

661 Raikan silta 0.00 1.95 1.58 2 1 1 1.8 10000

2613 Pitkänpohjanlahden silta 0.00 1.27 1.16 1 4.2 5 2.6 20000

738 Hyypiälän ylikulkusilta 0.00 1.72 1.79 1 3.4 1 1.8 90000

2549 Uitonsalmen silta 0.00 1.71 1.37 3 1 1 1 30000

703 Tokkolan silta 0.00 1.82 1.70 2 1.8 1 1 10000

870 Tiviän alikulkukäytävä 0.00 1.10 1.07 1 5 5 1 20000

377 Sudensalmen silta 0.00 1.88 1.66 1 2.6 1 1.8 20000

953 Sydänkylän silta 0.00 1.23 1.33 3.5 1 1 1.8 10000

700 Kirjavalan ylikulkusilta 0.00 1.42 1.98 1.5 1 1 1 60000

2142 Latikkojoen silta 0.00 1.43 1.58 2.5 2.6 1 1.8 20000

464 Jokisilta 0.00 1.19 1.25 3.5 1.8 1 1 20000

1025 Hartunsalmen silta 0.00 1.18 1.09 3.5 1.8 1 2.6 20000

95 Touksuon silta 0.00 1.83 1.18 2 2.6 1 2.6 20000

418 Laukassalmen silta 0.00 1.54 1.35 1.5 2.6 1 1.8 10000

420 Sillanmäenojan silta 0.00 1.20 1.07 1.5 2.6 1 1.8 10000



Framework for Unified Road Asset ManagementFramework for Unified Road Asset Management

National level allocation guidelines– Distribution data, individual projects not considered

Considers different asset classes simultaneously– Repair programs for pavements, bridges, gravelroads and road equipment

– Road condition tendance, e.g. winter-time snow plowing and road salt

Multiple evaluation criteria and incomplete information– Road safety, customer satisfaction, asset value and environmental effects

– Rank-orderings on criterion weights

Multiperiod model of 30 years– Deterioration and time discounting



Decision Support SoftwareDecision Support Software

RPM-Decisions©– Under development

– Demo available

Tool for the RPM-

framework– Standalone comput.

– Interactive analysis

of results through

Internet

www.rpm.tkk.fi



RPM-Decisions© FeaturesRPM-Decisions© Features

Spread-sheet form data input– Scores, costs and constraints

– GUI for preference elitation

Computation– Approximative algs. for large problems

– Exact algs. for up to 70 projects

Interactive analysis

– Core indexes, decision rules, robustness

– Score scatter plots, additional information



ConclusionsConclusions

Infrastructure asset management– Global challenge involving huge financial resources

– Large multi-criteria portfolio problem

– Incomplete information and multiple stakeholder groups

– RPM seems to offer a promising decision support framework

Further avenues– Integration of resource allocation between asset classes and programming

within asset class → two-level allocation model

– Detailed multi-year models

– Interactive processes; decision work shops with stakeholder representatives

supporting road asset management with portfolio decision analysis

Documents