INVEST storiesAshley FriezeOctober 2014

• We want to create value• Working usable software• Something complete and ready to go

• Value can be broken down• The iPad had value but not all the features of iPad3• Windows Notepad has value as a text editor but not all the features of Word• Therefore a product can be made incrementally• A big story can be decomposed into several end-to-end sub-stories

Why do we engineer stuff?

• Agree to spend time on something• Tracking completeness as “how much time is done”

• Do it until it’s done• With no results until the last piece is in place

• Do lots of things at once• Giving us lots of incomplete things

What do we often do?

• At some mid-point, you have to invest more to get ANY value out• Finish off the work you started• Back out things that can’t be completed• Tie up all the loose ends, regardless of how important they are

• Every assumption pushed into the start requires effort to release its value

What does this lead to?

• Feedback loops• Long cycle time means there’s no time to incorporate feedback• Running multiple ideas in parallel reduces cascading learning from each• Doing it all at once means we work entirely on initial assumptions

What’s missing?

• Why?• Which is the more valuable ½ TB hard drive?

So let’s make value in increments…

“How many have you done?”“I’ve done 80% of the time”“Yes but how many things are finished”“None yet”

And let’s track delivery in terms of complete things

“How many have you done?”“We’ve done half of them”

• Everything can be subdivided:• I – Independent – a thing which stands in its own right

(maybe you wouldn’t use it, but you can demo it)• N – Negotiable – continuously refine and rewrite it to make it fit• V – Valuable – there must be a specific end-user value• E – Estimatable – it must be understandable enough to give a decent estimate• S – Sized appropriately – not too big (>5 days) and not too small (5 minutes) • T – Testable – we will know when this is done

• All the stories can add up to a Feature or Epic, which is the larger thing we’re trying to do• The stories represent an end-to-end slice of the system

But stories are big, aren’t they?

• Value is broken into incremental, independent stories• Stories are completed one by one• Success = completing stories, not spending time• So track the number of stories completed…

…and break the work down into stories• Use the lessons of earlier stories to inform how to build/write future stories• Reduce the number of incomplete things…

…and the time to complete any individual thing

• So at any given point most of the value is ready to go……and we don’t need to add more effort to release the value so far

…and everyone will be happy

Summary