A fundamental requirement for Project
Management is to make sure estimating is correct. A number of differing techniques can be used and at least two different techniques should be used for each estimate. Where posible involving the people who will undertake the work in the estimating process.
-
Top Down
-
Bottom Up
-
Three Point Estimating.
-
Analogy
-
SLOC analysis
-
Functional Point Analysis
-
Wideband Delphi
-
Planning Poker
Planning Poker is an agile estimating and planning technique that is consensus based. Planning poker is a good technique to use in a bid phase as it is quick and involves the people with the skills to do the work. Most project teams will hold a Planning Poker session shortly after an initial product backlog is written. This session which may be spread over multiple days and facilitated by the project delivery manager is used to create initial estimates useful in scoping or sizing the project.
Because product backlog items (usually in the form of user stories) will continue to be progressed throughout the project, most teams will find it helpful to conduct subsequent estimating and planning sessions once per iteration. Usually this is done a few days before the next iteration and immediately following a daily stand-up, since the whole team is together at that time anyway.
To start a poker planning session, the product owner or customer reads a user story or describes a feature to the estimators. Each estimator has a deck of Planning Poker cards with values 0, 1, 2, 3, 5, 8, 13, 20, 40, 100 a ? (unsure), an infinity symbol (this task cannot be completed) and a coffee cup (I need a break). Standard playing cards of Ace, 2, 3, 5, 8 and king can be used. Where king means: "this item is too big or too complicated to estimate". "Throwing a king" ends discussion of the item for the current sprint. The values represent the number of story points this need to be quantified as days, hours or other units in which the team estimates.
The estimators discuss the feature, asking questions of the product owner as needed. During discussion, numbers must not be mentioned at all in relation to feature size to avoid anchoring. When the feature has been fully discussed, each estimator privately selects one card to represent his or her estimate. All cards are then revealed at the same time. If all estimators selected the same value, that becomes the estimate. If vide variances in the estimate are identified the estimators discuss their estimates. The high and low estimators should especially share their reasons. After further discussion, each estimator reselects an estimate card and all cards with a revised estimate are again revealed at the same time.
The poker planning process is repeated until consensus is achieved or until the estimators decide that agile estimating and planning of a particular item needs to be deferred until additional information can be acquired.
