Technical debt sources and impacts
- 1. Technical Debt – Understanding Its Sources and Impacts Through a Game David Croley - @davidcroley
- 3. David Croley Agile Velocity Principal Consultant Certified Scrum Manager ( CSM) @davidcroley dcroley@agilevelocity.com Transforming Technology Organizations 3
- 4. We’d prefer to deliver a fast, steady stream of new features…
- 5. But sometimes delivery feels slow, even stagnant. CC BY 2.0 http://www.flickr.com/photos/usfwspacific/6121377305/
- 6. And we hope it doesn’t feel like this!
- 7. Technical Debt A useful metaphor similar to financial debt “Interest” is incurred in the form of costlier development effort Technical Debt can be paid down through refactoring the implementation Unlike monetary debt, Technical Debt is difficult to quantify
- 8. Development Investment Visible Invisible Positive Value Negative Value Feature s Bugs Architecture *ilities Logging, metrics, A/B Testing, etc. Tech Debt
- 9. Good and Bad Debt Martin Fowler’s Technical Debt Quadrants http://www.martinfowler.com/bliki/TechnicalDebtQuadrant.html
- 10. No Blame Tech Debt is often the result of deliberate decisions or incomplete knowledge Even perfectly functioning teams will incur Tech Debt Change over time is another source of Tech Debt
- 12. Let’s do an exercise to understand the concept further. Form into Teams of at least 4 people.
- 13. Feature Cost: 15 Feature Cost: 10 Feature Cost: 5 Technical Debt Cost 15 Impact -10 Technical Debt Cost 15 Impact -10 Technical Debt Cost 10 Impact -5 Technical Debt Cost 5 Impact -5 Technical Debt Cost 5 Impact -5 Iteration Card Set up your board as follows
- 15. Feature Cost: 15 Feature Cost: 10 Feature Cost: 5 Technical Debt Cost 15 Impact -10 Technical Debt Cost 15 Impact -10 Technical Debt Cost 10 Impact -5 Technical Debt Cost 5 Impact -5 Technical Debt Cost 5 Impact -5 Iteration Card Add up the total impact of all technical debt items -35
- 16. 25 -35 X
- 17. Feature Cost: 10 Feature Cost: 15 Feature Cost: 10 Technical Debt Cost 15 Impact -10 Technical Debt Cost 15 Impact -10 Technical Debt Cost 10 Impact -5 Technical Debt Cost 5 Impact -5 Technical Debt Cost 5 Impact -5 Iteration Card You have 25 Points to Spend Select the cards you want to spend your points on. No partially done work. Feature Cost: 5 Feature Cost: 5
- 19. Feature Cost: 10 Feature Cost: 15 Feature Cost: 10 Technical Debt Cost 15 Impact -10 Technical Debt Cost 15 Impact -10 Technical Debt Cost 10 Impact -5 Technical Debt Cost 5 Impact -5 Technical Debt Cost 5 Impact -5 Iteration Card You have 25 Points to Spend Select the cards you want to spend your points on. No partially done work. Feature Cost: 5 Feature Cost: 5 Iteration Card Cost: 10 Database is getting large and complex. We need to add automated migrations to reduce manual work and support refactoring. Impact: -5
- 20. The goal is to complete as many feature points at the end of 5 iterations. Go!
- 21. -35 25 X
- 22. The goal is to complete as many feature points at the end of 5 iterations. Stop!
- 24. Debrief So how did it go? What strategy did your team use to mix features and debt? Is it realistic?
- 25. Simplifications Tech debt impact is usually not so quantifiable. Delivering significantly fewer features per sprint may be unrealistic. Cost to fix and impact may increase over time
- 28. Tools and Techniques Use tools like SonarQube, FindBugs, and PMD to help find and measure tech debt Ask the team Track defects by location in the code Make sure the team feels empowered to fix small debt issues every day
- 29. Boy Scout slide Incrementally make your code better
- 30. Keys to Prioritizing Technical Debt Have a Clear Definition of Done - Acceptance Criteria Articulate Business Value Work Incrementally - Breakdown Items Make Visible - Add to the Backlog Prioritize/ Allocate Time
- 31. 21 21 1 2 1 2 1 1 One Backlog Prioritized by the Product Owner Feature Story Technical Debt Story
- 32. 21 21 1 2 1211 21 21 1 2 1211 Feature Story Technical Debt Story Two Backlogs Prioritized Independently 80/20 Allocation Strategy
- 33. For More Information: Working Effectively with Legacy Code by Michael Feathers Clean Code: A Handbook of Agile Software Craftsmanship by Robert C. Martin http://www.ontechnicaldebt.com https://medium.com/@joaomilho/festina-lente-e29070811b84 (Tech debt 101)
- 34. David Croley – dcroley@agilevelocity.com Website – AgileVelocity.com Blog – AustinAgile.com Twitter - @austinagile, @davidcroley Thanks!
Editor's Notes
- #3: Thank the sponsors.
- #4: Couple questions? Who is working with software development teams? Who is employing Agile Methods? Who knows what Technical Debt is? Who is using Scrum? Who is using Kanban? Who has heard of Kanban before?
- #7: Attribution: http://www.flickr.com/photos/usfwshq/8426146245/in/photolist-dQAcHx-f8wNoo-cSUakj-f8wNhN-cD8Fhm-cyRqpf-bjfV3x-7HHtaY-aRr156-8aupg4-7LK1as-7LRCsG-abNnzs-951W8W-7LRB1J-cZaxJj-8juseK-cpe6EJ-aCy8xe-du4Qh6-bDSxTn-9tsUQP-azwePa-a1oo6r-dCoxvW-c1KAqW-8h18Ri-bxVC3z-ePXdaS-7Xr9rh-cNWatS-ds9QJu-ds9FpF-ds9R55-ds9Qq3-ds9RHj-ds9GSV-a98QGU-bdEkpe-aeyxri-eZ6vag-7UAhNN-8RjCKM-bmXXkL-cmPWC7-c5eSqQ-7GPcZu-7LMFkF-cMLTYo-8ejG7H-cmPWQq/lightbox/
- #8: Coined originally by Ward Cunningham
- #9: We’re used to seeing and investing in Features and Bugs, but there are other investments needed too. The Invisible side includes tech debt and architecture, but can also include a lot of the “ilities” that user’s don’t know they need until they are not there.
- #10: Questions: Which type of debt is the most prevalent? Are there other types of debt?
- #11: Change of requirements, feature usage
- #12: Symptoms Image attributions: http://www.flickr.com/photos/14511253@N04/4411497087/in/photolist-7HQ5oB-9qa4rb-7CHWy4-9q6Whp-8QjLj7-b7LaSn-9PUHMi-9oQ3qw-8iu4HN-9qxd3u-auQz9Z-a7Fctt-7ziiDq-9itKnt-dGN5VZ-8VV7NP-bBu2vW-bgDwNk-b4KooT-b4Kor8-b4Kota-b4KnT4-9qc58h-9q9okR-9q6gKK-9q7GDX-9q9uFw-7REcDB-amVpjf-aU2khT-bx9EXX-bjWDaT-9VryJk-7XZRgj-7XZQmu-7XWzb8-7PqVf7-avb9xS-avhS6v-9iL2JU-8kErPW-8wqZJZ-9q4aZp-9qgydX-9CbvHx-bkeVkw-aDb1kG-9bQLa4-9qfftM-7FK373-bB2cMe http://www.flickr.com/photos/98193606@N00/3466024918/in/photolist-6hhhsj-6hHv9z-6hJQ94-6kPYqY-6mCk9G-6zKJLm-6zXfNr-6FUTot-6Qk2Sx-6TkkWU-6VyFqc-6X65A7-6YdYmY-6YyCNJ-7enMRy-7kD9oV-7w9FHt-9zYUbN-7HQ5oB-7QWatV-bPLUhn-bvH8Dv-7WepXX-eETBiA-9zrNro-8hvJXJ-9y23Bn-7NGfDb-9BhUgv-9SUSTr-ccfa4q-ccfcoy-ccfaDG-bUSTZH-bUSXFx-bUSVMc-ccfcFN-bUSUFV-bUSWkR-ccfcvC-ccfaiS-ccfaJh-bUSUKZ-bUSWbt-ccfb7Y-bUSWuv-ccf9R5-ccfd8Y-bUSV9p-ccf8ru-ccf9BA http://www.flickr.com/photos/43088195@N03/4536619509/in/photolist-7UTmVK-8a9Ani-dsT1wn-7Tg2ay-e6QgRx-e6VUVU-e6QgV6-e6VUTs-e6VUYC-e6Qh78-dEPDR7-dEJgeB-8a9ATi-e5piNA-bSPPHi-cLQR4Y-7H1ohN-9cs4T6-8mazGL-8xD2HP-8mazfW-bDcUqf-bWJ7TK-9qPqp4-dgjFYo-e9LFvq-bUCP3e-8rYusH-effxjm-bos1RP-8pr8hQ-a43cdw-8zGsCp-bJBaf6-81kp1V-9PoYnz-bXcg7w-efty5g-ef9Jmx-8CFmHB-98nU74-dTPBLJ-ef9NEe-a9chF3-91Pp6J-drhmrN-dr6e6D-c3FT4W-83wM3S-dp1PwW-atS3cs http://www.flickr.com/photos/49503102897@N01/54389823/in/photolist-5NLcz-675rs-8zm7x-cJ3W6-n2cdj-p3S1H-r8fLX-rafFi-tpGed-tWtcr-yxxin-BHaEq-Cqe2K-Et2EX-J2cVe-ZYxen-2as17k-2cNeb2-2M4o2x-397sho-3eu4QL-3ftfgM-3nrv1i-3nR78L-3UbB1x-4kHKK1-4oDUyJ-4p3Eoa-4pDQzB-4A1f2M-4BidvL-4Ckoht-4LcGYe-4ThTPe-4XsfGQ-5nnZJL-5vAYu2-5xxLb9-5zbvKS-5B9ixa-5CiuF3-5G4WGv-5PXSRw-5RDD3C-5RE3QD-5RSP6E-5TaFQ8-5XCkjK-5YscQw-5YMBcR-61vEoa
- #13: Perhaps optional
- #16: Features backlog Tech debt has accrued and the technical team has identified it and estimated the work and estimated the business impact
- #25: Debrief What did you learn? Technical Debt Grows Share results (explain interesting ones)
- #26: Debrief - What did you learn
- #27: Coined originally by Ward Cunningham
- #29: Visualize your debt, make it explicit Photo by Oliver Hammond http://www.flickr.com/photos/olivander/58499153/
- #30: Photo by Kristi Johnson http://www.flickr.com/photos/46142663@N03/4451325321
- #32: http://commons.wikimedia.org/wiki/User:Roger_McLassus http://commons.wikimedia.org/wiki/File:2006-02-04_Metal_spiral.jpg The teams need to be allowed to work on things that improve their efficiency, not just features.
- #33: Incrementally make it better - be a good boy scout
- #37: Pair Share – someone you haven’t met yet
- #39: Please visit us at www.AgileVeloicity.com See http://agilevelocity.eventbrite.com/ for our upcoming classes and events!