Risk Assessment Toolbox - Esri · 2016 Esri Water Conference--Presentation, 2016 Esri Water Conference, Risk Assessement Toolbox- A Custom ArcGIS 10.2 Toolbox for Wastewater Asset

Risk Assessment ToolboxA Custom ArcGIS 10.2 Toolbox for Wastewater Asset Management

Case Study: The City of Mesquite, TX

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Presenters: Christina Hickey, PE, CFM; Umer Khan, EIT; Matt Stahl, EITProject Managers: Tim James, PE; John D’Antoni, PhD, PE; Preston Dillard, PE

City of Mesquite and Alan Plummer Associates, Inc.February 9, 2016

Agenda

• Project Description• Problems Solved• Technical and Python Highlights• Project Results• What’s New & Lessons Learned

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Project Description

• Scope: Perform a business risk assessment of the City of Mesquite, TX wastewater collection system. – 476 miles of gravity mains

• 8,512 pipeline segments • 3 to 72 inches in diameter• First pipe installed in 1922 • Mostly PVC (57%) & Clay (32%)

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Project Description

City of Mesquite, Texas4

• Mesquite Situation – Aging Infrastructure

Project Description

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• Mesquite GIS - Current: – Utility Data stored in Geodatabase– Relationships to other data (work order system, PAVER)– Web Service to allow editing of items in the field

• Future: Relating more of the assessment data

• Why GIS Centered?– Neighborhood Planning and Prioritization– Project coordination– Data already in GIS– Spatial factors used in the risk analysis

Project Description

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Project Description

• 9 Steps to a Business Risk Assessment

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Project Description

Risk of Failure = (Likelihood of Failure x Consequence of Failure)

How Severe Are the Consequences of Pipe Failure?

How Likely is It For the Pipe to Fail?

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Project Description

• Scoring: Custom risk assessment criteria and scoring were developed for the assets in the system.– Likelihood of Failure (LOF)– Consequence of Failure (COF)– Risk of Asset Failure (ROF)

• Prioritization: ROF scores prioritized individual assets for rehabilitation in Mesquite’s 5 year and 10 year capital improvement plan (CIP) and to manage future asset renewal priorities.

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Topics


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Problems Solved

• Risk Assessment Challenges– Geoprocessing (location-aware analyses) – Efficient and accurate asset scoring, from preliminary

through final iterations– Summary results and reporting by asset and asset

group

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Problems Solved

• Error Reduction With Database (vs Spreadsheet)

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Problems Solved

• Generic Risk MatricesSTRUCTURAL 100 100

YES NO Pipe Properties Wt. YES NO Health and Safety (injury, illness) Wt.

x 1 Condition (rating via direct inspection) x 1 Public health and safety 15

x x 2 Staff opinion of condition 25 x 2 Utility employees health and safety 10

x 3 Repair history (# / 1,000 ft / yr)

x 4 Time since second most recent repair (yr) Financialx 5 Age (yr) 25 x 3 Customers - Loss of revenue 10

x 6 Material 25 x 4 Utility - Loss of revenue

x 7 Joint Type x 5 Utility - Repair cost 5

x 8 No of connections (# taps/mile) x 6 Utility - Liability

x 9 Installation Contractor x 7 Utility - Inhouse Repair Capability

External Corrosion Public Conficencex 10 Soil resistivity (ohm-cm) x 8 Number of customers affected (interruption of service)

x 11 Soil chemistry - sulfates in soils (%) x 9 Loss of service to critical facilities (incl. lift stations) 15

x 12 Soil Moisture x 10 Public perception - service calls

x 13 Stray current

x 14 External corrosion protection Infrastructurex 11 Proximity to main roads or railroads 10

Internal Corrosion x 12 Aerial Crossing 10

x 15 Internal sewer corrosion levels

x 16 Sulfates in wastewater (mg/L) Regulatoryx 17 Internal corrosion protection x 13 Discharge to Sensitive Environments 10

x 14 SSO’s (# / 1,000 ft / yr) 10

External Stresses x 15 100-yr Floodplain 5

x 18 Burial depth (ft) 15

x 19 Embedment zone backfill (quality of pipe bedding)

x 20 Traffic Load

x 21 Canopy

HYDRAULICx 22 Flow Profile (% full)

x 23 Blockage history (# / 1,000 ft / yr)

x 24 Surcharge conditions

QUALITYx 25 Odor complaints 10

LIKELIHOOD OF FAILURE COMPONENTS CONSEQUENCE OF FAILURE COMPONENTS

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Problems Solved

• Custom Risk Matrices

LOF ParameterWeight

(%)Staff Opinion 25Age 25Material 25Burial Depth 15Odor Complaint 10

TOTAL 100

COF ParameterWeight

(%)Public Health 15Utility Repair Safety 10Customer Loss 10Utility Repair 5Critical Service 15Proximity To Road 10Aerial Crossing 10Discharge To Sensitive Environment 10Sanitary Sewer Overflow 10100-yr Floodplain 5

TOTAL 100

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Problems Solved

• Multiple iterations performed quickly

Risk Results

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Topics


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Technical and Python Highlights

• Custom toolbox developed from geoprocessing tools

• Toolbox Layout– LOF– COF– Score and Plot

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• Field Mapping to Import Data to Geodatabase

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• Arcpy.da Cursors – Ex 1: Data Processing (Pipe Age)

Cursor scores data per matrix

Pipe Age tool

Variables

AgeYrs AgeYrsScore

> 0 – 10 1> 10 – 20 3> 20 – 30 5> 30 - 50 7> 50 10

<null> 5

Dictionary input

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• Arcpy.da Cursors – Ex 2: Geoprocessing (Road Prox)

Pipe Proximity to Roads tool

(Spatial selection by roads)

Cursor scores data per matrix

Lookups

DiamInch RoadClass ProxRoadsScore DiamInch RoadClass ProxRoadsScore0 to 8 5 0 to 8 88 to 24 7 8 to 24 824 to 30 9 24 to 30 10> 30 10 > 30 100 to 8 3 0 to 8 2

8 to 24 4 8 to 24 3

24 to 30 5 24 to 30 4

> 30 6 > 30 5

0 to 8 28 to 24 324 to 30 4> 30 5

FREEWAY; FRONTAGE;

ACCESSRAILWAY

UNKNOWNMAJOR

LOCALDictionary input

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• Arcpy Cursors – Ex 3: Calculations (Hydr Capacity)

Calcs

Hydraulic Capacity tool

Cursor assigns values per matrix

Variables

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• Risk Calculation

LOFtool

COFtool

Risk Score and Ranktool 22

Topics


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Project Results

• Risk Analysis Workflow– Import asset data and custom scoring matrices– Geoprocessing (point, polyline features)– Database processing and matrix scoring– Results and reports (draft through final)

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Project Results

• Prioritize to Evaluate– Rank and prioritize every pipe– Triage physical evaluation

(CCTV, inspection)– Evaluation guides decisions:

• Rehabilitation• Replacement• Monitor

• Risk matrix refinement

High Moderate Low

High ImmediateRehab/Replace

ProgrammedRehab/Replace

Repair/Replaceon failure

Moderate ImmediateRehab/Replace

Proactive Assessment

Monitor and Forecast

Low Proactive Assessment

Opportunistic Assessment/forecasting

Monitor and ForecastLi

kelih

ood

of F

ailu

re

Consequence of Failure

Risk based Framework for Prioritization

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• Map reports (Data Driven Pages) - link

Project Results

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Project Results

• Summary reports (Data Driven Pages)

Summary Statistics (ArcGIS table)

Individual Values (ArcGIS table)

Locator Map (ArcGIS DDP)

Summary Plots (Matplotlib jpegs via

Raster Catalog)

Report/Plot Tools

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Topics


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What’s New & Lessons Learned

• What’s New– Arcpy.da cursors

– Python dictionaries

– Data Driven summaries

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• Dictionary lookup - Personal geodatabase via Excel named range

– Excel table (name range) is source and editable – Personal geodatabase (linked to Excel) is dynamic*– Arcpy reads dictionary from .mdb

*Avoids schema locks; instantaneous updates from source30


• Map summaries with charts/tables (Data driven)

Data Driven Pages

Image path - index layer field

Bar & scatter charts (stand-alone script)

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• Future Work– Regular Risk

Assessment updates– Custom tool validation,

default values, etc– Layer selection tools– Toolbox as client

deliverableFuture

Client Meeting

Risk Matrices

Toolbox Dictionary

Results

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Questions?

• Useful References– ESRI.com– Python.org– Matplotlib.org– Stackoverflow.com

• Contact Information– Christina Hickey - [email protected]– Umer Khan - [email protected]– Matt Stahl - [email protected]

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Documents

Risk Assessment Toolbox - Esri · 2016 Esri Water Conference--Presentation, 2016 Esri Water Conference, Risk Assessement Toolbox- A Custom ArcGIS 10.2 Toolbox for Wastewater Asset