technical debt - why should you care? (agiles buenos aires 2011)
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Oh, no! Another session about technical debt?!?
Maybe we could discuss other things….
before we start…!}!
what the hell is happening with this project?!?
before we start…!}!
what the hell is happening with this project?!?
How is your boss here?
Technical Debt!Why should you care?!
www.ciandt.com!
{!
Paulo Roberto Camara Tech Manager at Ci&T [email protected] @proberto98
which opCon would you go for?
• the easy and quick way, but the code doesn’t look very nice… Future will be dark…
• a cleaner and more sophisCcated design, but it will take longer to put in place. No clouds ahead!
really?
really, really?
ah, ok….
“Technical debt is everything that makes your code harder to change.” (Tom Poppendiek)
such as….
• no design • poor design • duplicated code • deprecated code • un-‐tested code • complex code • any kind of “workaround”…
the metaphor…
• every Cme you choose the first opCon (the quick and dirt way) you create debt (like a financial debt) – if it is a debt, it incurs interest
• you may pay only the interest • or you may pay down the principal, reducing the interest in the future
interest?!?
• bugs • extra effort • slower development • delays
hTp://theagileexecuCve.com/category/technical-‐debt/
“Every minute spent on not-‐quite-‐right code counts as interest on that debt. EnCre engineering organizaCons can be brought to a stand-‐sCll under the debt load of
an unconsolidated implementaCon…” (Ward Cunningham, 1992)
Technical Debt Quadrant (by MarCn Fowler @ Agile Brazil 2010)
hTp://www.marCnfowler.com/bliki/TechnicalDebtQuadrant.html
why should you care?
interest?!?
• bugs • extra effort • slower development • delays
a liTle context
(before I show you what I am really talking about)
2010
Ci&T at a glance!}!
www.ciandt.com / @ciandt!
Founded in 1995!HQ in Brazil w/ offices in the US, Japan, Europe & China!
Global Delivery Centers in Brazil, Argentina and China !Staff: 1,300+!Annual growth: 40%!Provide high performance teams to our clients!
Our Clients }!
www.ciandt.com / @ciandt!
What we do!}!
www.ciandt.com / @ciandt!
Service Offerings!
Application Development & Management!Mobile Solutions!Cloud Computing!Product Engineering!SAP!Business Intelligence!!
How we do it }
www.ciandt.com / @ciandt!
Ci&T runs 100% !Agile projects!!
some sad stories
(and fortunately other very happy ones!)
do you remember this chart?!}!
what the hell is happening with this project?!?
it is a true project… L • criCcal Cme to market milestone • prudent technical debt (“let’s fix it later!”) • yes! We met the milestone! J • but…. a new “criCcal” milestone was set… • more reckless technical debt (“refactoring is for losers!”) • things got more difficult (extra effort, extra bugs, frustrated
team, unhappy customer…) • we didn’t meet the second milestone… L • two sprints spent on refactoring, almost no new
funcConality delivered… • a long Cme to recover credibility.
Design Stamina Hypothesis (by MarCn Fowler @ Agile Brazil 2010)
hTp://www.marCnfowler.com/bliki/DesignStaminaHypothesis.html
let’s look another example…
almost 40% of the total sprint capacity
and quality has became an issue…
what a hell is happening with this project?!?
lack of automated tests, coCnuos integraCon! • complex billing system for an Insurance company • lots of integraCons with legacy systems • automated tests were not easy to be created (and kept
working later!) • and the Product Owner didn’t accept to spend sprint
capacity with “no useful code” • aber a lot of conversaCon – and problems – team was able
to create a minimal test suite (one enCre sprint spent on that!)
• keep this tesCng code up and running had become part of the definiCon of done
• in the following sprint, regression tests effort dropped half as well as the bugs found by the PO! J
a good reference now!
• a large building company
• an 18 months project • high technical and business complexity
• company board as the main stakeholders
• Ci&T’s team: 12 people • monthly deliveries • currently at sprint 12
technical debt under control! • code standards / design / code reviews / frequent refactoring – cost to add new features is almost the same since sprint 3
• conCnuous integraCon / automated tests – daily builds deployed on customer environment – completely automated deploy process – merge Cme reduced to zero
• quality – from 0,1 bugs / KLOC to 0,06 bugs / KLOC on producCon
but how?!?
how to pay the debt?
1 – register
2 – evaluate
3 – do not accumulate
conCnuous integraCon
TDD
code reviews
refactoring
...
4 – pay
and how about the product owner?
(because it seems he is somehow important, doesn’t it? J )
you may see him as the bad guy…
Ø pushing the team very hard
Ø adding unnecessary complexity
Ø not opened to technical arguments
but he is the one who will have to pay for the debt eventually!
it is all about communicaCon • The product owner – usually -‐ does not know what is refactoring, code review, TDD, etc – And he does not need to know!
• But he needs to know what is the size of the debt and make conscious decisions about when and how to pay it – Keeping him in the loop is a team responsibility!
final words
(if you have just waken up)
Paulo Camara [email protected]
hTp://www.linkedin.com/in/proberto
proberto98
this deck: h\p://bit.ly/mWmqan
?
good references Sites • Being Agile – blog interno da Ci&T • hTp://www.controlchaos.com/ • hTp://www.mountaingoatsobware.com/scrum • hTp://jeffsutherland.com/scrum/ • hTp://www.scrumalliance.org/arCcles • hTp://www.agilechronicles.com/
Books • Agile Project Management with Scrum -‐ by Ken
Schwaber • Lean Sobware Development: An Agile Toolkit -‐ By
Mary Poppendieck, Tom Poppendieck • Agile and IteraCve Development: A Manager's
Guide -‐ By Craig Larman • Agile Sobware Development -‐ by Alistair Cockburn
ArCcles • CMMI® or Agile: Why Not Embrace Both! – by Hillel
Glazer, Jeff Dalton, David Anderson, Mike Konrad and Sandy Shrum
• PracCcal Roadmap To Great Scrum -‐ Jeff Sutherland, Ph.D., October 20, 2009
• Scrum and CMMI -‐ Going from Good to Great, Carsten Ruseng Jakobsen, Jeff Sutherland, Ph.D.