(a radical interpretation) tomo lennox bow tie computer services why agile works
TRANSCRIPT
(A radical interpretation)
Tomo LennoxBow Tie computer services
Why Agile Works
Why Agile works 2
Tomo Lennox - Bow Tie computer services
Traditional Assumption #1• Developers do Analysis, specification, design,
development and tools, but not testing.
• Testers test and they don’t have the skills or the time for anything else.
• (A really smart tester can sometimes be promoted to development.)
• (Underperforming developers can be assigned to do testing but they aren’t good at it, because testing takes a destructive attitude that developers don’t have.)
Why Agile works 3
Tomo Lennox - Bow Tie computer services
Traditional Assumption #2• Testers are needed mostly at the end of
projects, so they move from project to project to optimize their time.
• Testers are not part of the project, they are a service to many projects.
• Any innovations tester make have to apply to all products.
Why Agile works 4
Tomo Lennox - Bow Tie computer services
Traditional Assumption #3
• Everyone knows that test automation is wonderful, but the developers are too busy, and the testers are not developers.
• Automation needs to work at the user interface level, because that is what testers have access to.
Why Agile works 5
Tomo Lennox - Bow Tie computer services
Traditional Assumption #4
• Any code you add to the product increases the risk of bugs, so don’t include anything customer did not pay for.
• Proper testing is black-box, the way the end users would see the system.
Why Agile works 6
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Traditional Assumption #5• You can’t test until the spec is really solid.
• Once you start testing, you should not change the software until you are done with a test cycle.
• It can take a long time to find some bugs, so you have to leave a lot of time for it.
(Go slow, even if it kills the schedule.)
Why Agile works 7
Tomo Lennox - Bow Tie computer services
Agile concepts• A Team works together, in one place, on one project
until it is done.
• Teams are composed of agile members, with a broad range of skills.
• Everyone takes on the tasks they can do to prevent a bottleneck.
• No sprint is done until is “done done.”
Why Agile works 8
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Agile Effect # 1
Instead of working on other projects while developers do the specification, testers participate in the specification.
• The product design is influenced by the need to test it.
• Test development can start before the development.
Why Agile works 9
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Agile Effect #2When testing becomes the bottleneck, developers jump in to help.
• Developers see software as a solution to every problem, so they write test tools.
• Tools dramatically increase the speed and accuracy of testing.
Why Agile works 10
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Agile Effect #3
With testers on the design team, and developers doing test tools, the product is built with test interfaces.
• Test interfaces allow deeper testing.
• Test interfaces make testing easier.
• Test interfaces allow test automation.
Why Agile works 11
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Agile Effect #4With tests that are written earlier, more automated and tightly integrated, programmers get rapid (maybe instant) feedback on their bugs.
• When you know what you just did, and you know what it does wrong, you usually know how to fix it. Now!
• With more bugs caught during development, much less time is spent looking for bugs after their cause is forgotten.
• The debugging phase can be nearly eliminated.
Why Agile works 12
Tomo Lennox - Bow Tie computer services
Wild Conclusion
I assert that the productivity increases associated with Agile testing are so great, that they can account for all of the productivity improvements seen in Agile projects.
Why Agile works 14
Tomo Lennox - Bow Tie computer services
Questions?
Faster
CheaperBetter
? ????
Why Agile works 15
Tomo Lennox - Bow Tie computer services
Assertion:
• If you tell a programmer that they broke something last month, they go looking for it. (It does not even matter if they were the one who broke it, they won’t remember.)
• If you tell a programmer that they broke something yesterday, they know what they were working on and will go fix it.
Why Agile works 16
Tomo Lennox - Bow Tie computer services
Human Memory Example 1
• Who did you talk to on the phone?
• Today? I remember
• This week? Check the call log
• 5 weeks ago Find the phone bills, then find last month (You might have to check on line. Do you remember the URL and password?) Then scan through for the week.
Why Agile works 17
Tomo Lennox - Bow Tie computer services
Human Memory Example 2
You dropped your keys:
• 5 seconds ago Look down
• 15 minutes ago Back track
• Three days ago Make a list of the places you have been. Call public places that have lost-and-founds. Post signs in popular places. Think about changing your locks.