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How Specification by Exampleand Test-Driven-DevelopmentHelp to Avoid Technical Debt

Wolfgang Trumler,Frances Paulisch

Corporate Technology,Germany

Siemens Corporate TechnologyRestricted © Siemens AG 2016

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Can we avoid Technical Debt?

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NO!

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Do we want to avoid Technical Debt?

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It depends!

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Quadrants of Technical Debt by Martin Fowler

“We don't have time todiscuss the requirementsin such a detail.”

"What's that featureall about?"

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How technical debt is introduced

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How to address these issues

Specification by Example

Acceptance Tests

Unit Tests

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Specification by Example

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Specification by Example

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Acceptance Testing with Cucumber

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Unit Testing

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Addressing the Quadrants of Technical Debt

Specificationby Example

Acceptance &Unit Tests

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Defect Rate

Defects / 1k Lines of Code

http://www.mayerdan.com/ruby/2012/11/11/bugs-per-line-of-code-ratio

In-house testing (not completed yet)

• All reported: 7.42

• Related to our component: 4.64

In-house Testing Released Product

Industry Average 15 - 50

MicrosoftApplications 10 – 20 0.5

Cleanroomdevelopment 3 0.1

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The Role of the Architect

RefactorDesignUp-frontDesign

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Summary

We applied• Specification by Example• Acceptance and extensive Unit Testingto avoid technical debt in late phases of the project

Used Defect Rate as performance indicator

Methodology mix worked well for us (very low Defect Rate)

Planning to roll-out on broader scale

Thank you!

Wolfgang TrumlerFrances Paulish

Corporate TechnologyGermany

Thank you