Spaghetti

Spreadsheets

Untangled

Benefits of decision modeling

when uncovering complex

business logic hidden in

spreadsheets

Charlotte Bouvy MSc

DecisionCAMP 2019 Bolzano

Intro speaker

• MSc Cognitive Artificial Intelligence (Utrecht University, The Netherlands)

• 20+ years experience in bridging the gap between business and IT (knowledge engineering, business rule management, business architecture)

https://www.linkedin.com/in/charlottebouvy/

Sociale Verzekeringsbank (SVB)

• implements national (social) insurance schemes in the Netherlands• child benefit, AOW pension, Anw survivor benefit

• personal budget scheme under Social Support act

• mission• excellent service

• stable flexible organization

• close cooperation with chain partners

BRM at SVB

• Business Rule Management key in their business innovation

• ‘wizards’ support the 1500 case workers with knowledge intensive decisions in the primary process

• decision modeling manages complex rules

• a multidisciplinary team speeds up development

• cost-effective business case speeds up change process

Our case

• Operational control and audit departments of SVB

• Account periodically towards ministries• To comply with the law that structures the execution of work and income

regulations

• Lawfullness• Were the assessments done according to the laws and regulations

• Did every citizen receive the amount he/she was entitled to

• Reliability• Is the financial statement a faithful representation of the actual payments

who

why

what

Problem #1

• Knowledge scarce… and about to walk away

Problem #2

• Spreadsheets applied everywhere..

… but error prone

DILBERT © Scott Adams. Used By permission of ANDREWS MCMEEL SYNDICATION. All rights reserved.

• What We Know About Spreadsheet Errors

Ray Panko, professor IT managementauthority on bad spreadsheet practices“the issue is how many errors there are, not whether an error exists”

• European Spreadsheet Risk Interest Group collects horror stories

• How a spreadsheet fail lead to questionable global fiscal policy

Spreadsheet errors

http://panko.shidler.hawaii.edu/SSR/Mypapers/whatknow.htmhttp://www.eusprig.org/horror-stories.htmhttps://www.nytimes.com/2013/04/19/opinion/krugman-the-excel-depression.html

Problem #3

• Dealing with the domain specific business logic details

Our solution: SARA

• Statistical Application for Analysis of Lawfulness (‘Rechtmatigheid’)

• Replaces different spreadsheets

• Modeled in Oracle Policy Automation

3 main benefits of SARA

1. Faithful representation of calculation and decision knowledge

2. Data separated from calculation and decision model

3. Model is both ‘single source of truth’ and versatile implementation

Benefit #1 faithful representation of knowledge

• Semantics semantics semantics

• Concept model

• Transparency (less assumptions)

• Explicit unambiguous names

• Levels of abstraction

• Logical decomposition

Before SARA

Our solution: SARA

SARA high levelDomain

Law

Law

Stratum Stratum Stratum

Sample Sample

Stratum

Sample

Stratum Stratum

Sample Sample Sample

• Stratified sampling

• Estimation on level of strata

• Aggregation on law and domain level

• ‘base level’ rule:

error = SOLL - IST

• Calculation modes

• ‘absolute’ for lawfulness

• ‘netted’ for reliability

estimation

aggregation

Modeling calculations rules vs spreadsheet

the percentage of lawfullness for the stratum =

100 - the percentage of unlawfullness for the stratum

the percentage of unlawfullness for the stratum =

the estimated error amount for the stratum / the IST amount for the stratum

the estimated error amount for the stratum =the estimated SOLL amount for the stratum – the IST amount for the stratum

the inaccuracy for the stratum = Sqrt(1 – the square of the correlation between IST and SOLL for the stratum) * the t-value for the stratum * the standard deviation of the SOLL for the stratum * (the number of cases in the stratum / Sqrt(the number of cases in the sample in the stratum)) * Sqrt((the number of cases in the stratum - the number of cases in the sample in the stratum) / (the number of cases in the stratum - 1))

less straightforward

Modeling calculations and decisions

Modeling calculations and decisions

Benefit #2 separation of data and model

• Manual data copy paste actions cause spreadsheet errors

• Extraction, transformation, loading of data (from different sources) are different responsibilities

• Important: data sets with enough coverage to test the model• Business scenario’s as acceptance criteria

Benefit #3 executable model

• Model is both ‘single source of truth’ and versatile implementation

• Mature, scalable, secure, stable, repeatable

• Service oriented

• Version control, change management

Integrated with case management solution Octopus –SOAP webservices to load input

and save results

Deployed as web interview -data input by RPA

Input screens

Result screen

Modeling and testing business scenarios in OPM

Different ways to execute SARA

Lessons learned

• Spend time with business and SME’s to discover together the value todeliver ∞

• Make a business vocabulary

• Without business scenario’s for acceptance testing a user story is not ‘ready for sprint’

∞“Discover to Deliver” by Ellen Gottersdiener & Mary Gorman