AW2 Concurrent Session 11/7/2012 10:15 AM 

       

"Pay Now or Pay More Every Day: Reduce Technical Debt Now!"

   

Presented by:

Fadi Stephan Excella Consulting

       

Brought to you by:  

  

340 Corporate Way, Suite 300, Orange Park, FL 32073 888‐268‐8770 ∙ 904‐278‐0524 ∙ sqeinfo@sqe.com ∙ www.sqe.com

Fadi Stephan Excella Consulting

Fadi Stephan is an agile coach, trainer, and consultant with Washington DC-based Excella Consulting. Fadi has more than twelve years of professional experience as a product manager, project manager, software developer, and consultant in businesses ranging from start-ups to Fortune 500 companies. Since 2006, his focus has been on agile adoption and on transitioning, coaching, and mentoring organizations and teams in agile practices. Fadi is a certified Project Management Professional (PMP) and a Certified Scrum Professional (CSP), founder of the DC Software Craftsmanship user group, and organizer of the DC Scrum user group.

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Managing Technical Debt

Managing Technical Debt

Fadi.Stephan@excella.com @FadiStephan AgileJourneyman.com/2012/05/managing-technical-debt.html

Pay Now or Pay More Every Day – Reduce Technical Debt Now!

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About Fadi Stephan

• 15+ years of experience in software development

• Focused on Agile since 2006

• Consultant with Excella

• Founder of the DC Software Craftsmanship User Group

• Organizer of the DC Scrum User Group

What’s Going On?

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Velocity

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Rigidity

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Immobility

Viscosity

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Deadline

Broken Window

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Over Architecting

Bad Design

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Poor Skills

Technical Debt

“Shipping first time code is like going into debt. A little debt speeds development so long as it is paid back promptly with a rewrite... The danger occurs when the debt is not repaid. Every minute spent on not-quite-right code counts as interest on that debt.”

- Ward Cunningham

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Technical Debt Metaphor

“Neglecting the design is like borrowing money”

“Refactoring, it's like paying off the principal debt”

“Developing slower because of this debt is like paying interest on the loan”

“Every minute spent on not-quite-right code counts as interest on that debt”

Principal

Interest

Technical Debt

Quick and dirty design results in

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Trading for Quality

Design Stamina Hypothesis

martinfowler.com/bliki/DesignStaminaHypothesis.html

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Which one will you choose?

1. Quick and Dirty

2. Clean

Home or car loan

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Technical Debt Quadrant

martinfowler.com/bliki/TechnicalDebtQuadrant.html

Types of Debt

• Unintentional

• Intentional

– Short term & focused

– Short term & unfocused

– Long term

• Only short term focused debt & long term debt are “good” debt

forums.construx.com/blogs/stevemcc/archive/2007/11/01/technical-debt-2.aspx

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theagileexecutive.com/category/technical-debt

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Technical Debt Management Plan

Register the Debt

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As I prudent developer,

I am deliberately taking on technical debt by

…

…

so that…

Date: 2/10/2012

Impact: M

Estimate: 3

As I prudent developer,

I want to refactor ….

…

…

so that I can repay the technical debt

Estimate: 8

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Technical Debt Backlog

Story Dirty Estimate

Clean Estimate

On Going Impact

Date

…

3 8 H 2/5/2012

… 1 5 M 2/10/2012

… 3 13 L 2/11/2012

Complexity

Code Coverage

Duplication

Rule Violations

Design

Evaluate Code Base

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Technical Debt = #items * #hours/item * $/hr

Monetize the Debt

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Technical Debt Plugin

Debt(in man days) = cost_to_fix_duplications + cost_to_fix_violations + cost_to_comment_public_API + cost_to_fix_uncovered_complexity + cost_to_bring_complexity_below_threshold + cost_to_cut_cycles_at_package_level

SQALE

Changeability Maintainability Security Reliability Testability Efficiency Portability

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sqale.org/wp-content/uploads/2012/04/SQALE-3RD-WS-on-MTD.pdf

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Requirement Remediation Details Remediation Function

No commented out blocks

Remove 1 min/occurrence

At least 70% code coverage

Write tests 20 min/per uncovered line

Code overrides both equals and hashcode

Write code and tests 1 hr/occurrence

Sample Remediation Functions

sqale.org/wp-content/uploads/2012/04/SQALE-3RD-WS-on-MTD.pdf

SQALE Pyramid

sqale.org/wp-content/uploads/2012/04/SQALE-3RD-WS-on-MTD.pdf

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History

Cost = 2,000,000 Profit=10,000,000 Debt =3,000,000 ROI = (10M – 2M)/ 2M = 400%

theagileexecutive.com/category/technical-debt/

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theagileexecutive.com/tag/the-agile-triangle/

3,000,000 2,000,000

10,000,000

ROI = (10M – (2M + 3M))/ 5M = 100%

theagileexecutive.com/tag/the-agile-triangle/

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How much debt is too much debt?

Metaphor

• Think of 3 more examples of ways to use the technical debt metaphor

– Analogy 1:

– Analogy 2:

– Analogy 3:

• Do you think the technical debt metaphor works well?

• If not, why?

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Paying Down The Debt

Pay debt with high interest rate 1st

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Approach

• Have a technical debt reduction sprint immediately after a release

• Have a technical debt reduction sprint once we reach a certain limit

• Rotate dedicated members to work on reducing technical debt

• Dedicate 10% of each sprint to reducing technical debt

• Reduce technical debt by story

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Summary

Managing technical debt requires that we make prudent and deliberate decision on

design & quality

Summary

Provide transparency by

1. Registering any new debt

2. Assessing existing debt

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Summary

Inspect by

1. Monetizing the debt

2. Establishing a debt limit

3. Monitor trends

Summary

Adapt by

1. Paying down the debt focusing on high interest rate 1st.

2. Starting with what you know. Train for the rest

3. Continuously monitor the debt

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AgileJourneyman.com @FadiStephan

Acknowledgement

Robert Martin Martin Fowler Israel Gat Steve McConnell

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References

• Design Principles and Design Patterns - Robert Martin

• Design Stamina Hypothesis - martinfowler.com/bliki/DesignStaminaHypothesis.html

• Technical Debt Quadrant - martinfowler.com/bliki/TechnicalDebtQuadrant.html

• The Agile Triangle –

theagileexecutive.com/tag/the-agile-triangle/

• Technical Debt Assessment and Reduction –

theagileexecutive.com/category/technical-debt/

• Technical Debt, Cutter IT Journal October 2010 - www.cutter.com

References

• Technical Debt A Perspective for Manager – www.infoq.com/articles/technical-debt-levison

• Managing Technical Debt - blogs.versionone.com/agile_management/2011/07/11/managing-technical-debt/

• What Testers Can Do About Technical Debt - www.stickyminds.com/sitewide.asp?ObjectId=3629

• Climb Out of Technical Debt – www.ayeconference.com/climboutoftechnicaldebt/

• Don't Live with Broken Windows –

www.artima.com/intv/fixit.html

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References

• Technical Debt - forums.construx.com/blogs/stevemcc/archive/2007/11/01/technical-debt-2.aspx

• Sonar – http://www.sonarsource.org/evaluate-your-technical-debt-with-sonar/

• Pay Down your Technical Debt – www.codinghorror.com/blog/2009/02/paying-down-your-technical-debt.html

• SQALE Method For Evaluating Technical Debt – http://www.sqale.org/wp-content/uploads/2012/04/SQALE-3RD-WS-on-MTD.pdf

Pictures

• http://www.flickr.com/photos/49531720@N00/247730111/ • http://www.flickr.com/photos/89306448@N00/2247180420/ • http://www.flickr.com/photos/71962092@N00/2874328851 • http://www.flickr.com/photos/16857236@N03/2429136239 • http://www.flickr.com/photos/tpapi/2765541278/ • http://www.flickr.com/photos/97041449@N00/5261698908/ • http://www.flickr.com/photos/7389424@N05/2351559480/ • http://www.flickr.com/photos/24293932@N00/1144691293/ • http://www.flickr.com/photos/17454738@N00/2245445147/

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Pictures

• http://www.flickr.com/photos/25196025@N00/381877979/ • http://www.flickr.com/photos/25507200@N07/3120849218/ • http://www.flickr.com/photos/39516732@N08/4666623572/ • http://www.flickr.com/photos/64211362@N02/6338814898/ • http://www.flickr.com/photos/66622362@N00/3353570653/ • http://www.flickr.com/photos/23327787@N08/3027534098/ • http://www.flickr.com/photos/37815348@N00/5398908333/ • http://www.flickr.com/photos/51035555243@N01/155589939/