In Defense of Large Numbers
by Mike Cohn, 28 November 2011 | The Agile Blogosphere
This post is from Mike Cohn's Blog - Succeeding With Agile® by Mike Cohn. Click here to see the original post in full.
People are often surprised that I allow (or even encourage) people to estimate with story points as large as 20, 40, and 100. We include these values in the decks of Planning Poker cards that we sell and give away in classes and at conferences. Yet many people tell me they start out my taking the 20, 40 and 100 cards out of the deck and throwing them away.
I find this unnecessary and, in some cases, detrimental to good planning. These large numbers can play a role in estimating and planning on some projects. Let’s see how.
Suppose your boss wants to know the general size of a new project being considered. The boss doesn’t need a perfect, very precise estimate. Something like “around a year” or “three to six months” is enough in this case. To answer this question you’ll want to write a product backlog. You want to put no more effort into this than you need to. Since the boss wants a high-level estimate, you can write a high-level product backlog. Big user stories (“epics”) that describe large swaths of functionality will suffice.
And these epic user stories can be estimated with the large story point values.
Do you want to do this on every project? No, definitely not....
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