Clint Eastwood in the Rookie

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Chapter 22

Why Agile Planning Works

"If you want a guarantee,

buy a toaster."

--Clint Eastwood in The Rookie

Having arrived at this point, we are well equipped to look at why agile estimating

and planning are successful. First, remember the purpose of estimating and

planning. Planning is an attempt to find an optimal solution to the overall product

development question: features, resources, and schedule. Changing any one

of these causes changes in the others. While planning, we are exploring the entire

spectrum of possible solutions of how to mix these three parameters such

that we create the best product possible. The estimates and plans that we create

must be sufficient for serving as the basis for decisons that will be made by the

organization. In this chapter, we consider the agile estimating and planning process

described so far by this book to see how it achieves these goals.

Replanning Occurs Frequently

One of the ways in which agile estimating and planning support the efficient exploration

of the new product development solution space is through frequent replanning.

At the start of each new iteration, a plan for that iteration is created.

The release plan is updated either after each iteration or, at worst, after every few

iterations. Acknowledging the impossibility of creating a perfect plan goes a long

way toward reducing the anxiety that accompanies such a goal (Githens 1998).