Agile in a Flash 17 - INVEST in your stories – The Plan

INVEST in your stories – The Plan

Agile in a Flash by Jeff Langr and Tim Ottinger (card #17)

> Independent

> Negotiable

> Valuable

> Estimable

> Small

> Testable

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Customers describe their needs as briefly stated stories, best captured in a few words on index cards. Vet these candidate stories against Bill Wake’ s INVEST mnemonic (see http://xp123.com/xplor/xp0308). Fix them if they’re not up to snuff.

Independent Your customer wants cool features now, not boring data inputscreens. Can you deliver? Yes! Each story is an independent, incremental need. You don’t need the “add” story yet. Life isn’t neat and orderly.

Negotiable A story is not a contract! It’s a promise for more communication. Don’t fill your story cards with every last detail.

Valuable Stories represent small bits of business value for your customer. Each implemented bit lets them see what you can deliver and provide feedback. Stories promising implementation of technical details (such as “build a database layer”) provide no visible business value—never create them!

Estimable A reasonable estimate might not exist if a story is too big or if you don’t know what’s involved. Go back to the drawing board.

Small Stories are small, many fitting into an iteration and none approaching the full iteration’s length. An ideal story would take your team a day to deliver.

Testable If you can’t verify a story in some manner, you’ll never know when it’s done! Tests are often the best way to flesh out your understanding of a story.