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Used to estimate effort or relative size of user stories in software development .
Why is it useful?
- The reason to use Planning poker is to avoid the influence of the other participants.
- If a number is spoken, it can sound like a suggestion and influence the other participants’ sizing.
- Planning poker should force people to think independently and propose their numbers simultaneously. This is accomplished by requiring that all participants show their card at the same time.
How do I use it?
A typical deck has cards showing the Fibonacci sequence including a zero:
0, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89
other decks use similar progressions.
The reason for using the Fibonacci sequence is to reflect the inherent uncertainty in estimating larger items. At the estimation meeting, each estimator is given one deck of the cards. All decks have identical sets of cards in them.
The meeting proceeds as follows:
- A Moderator, who will not play, chairs the meeting.
- The Product Manager provides a short overview. The team is given an opportunity to ask questions and discuss to clarify assumptions and risks. A summary of the discussion is recorded by the Project Manager.
- Each individual lays a card face down representing their estimate. Units used vary – they can be days duration, ideal days or story points .
- During discussion, numbers must not be mentioned at all in relation to feature size to avoid anchoring .
- Everyone calls their cards simultaneously by turning them over.
- People with high estimates and low estimates are given a soap box to offer their justification for their estimate and then discussion continues.
- Repeat the estimation process until a consensus is reached. The developer who was likely to own the deliverable has a large portion of the “consensus vote”, although the Moderator can negotiate the consensus.
- An egg timer is used to ensure that discussion is structured; the Moderator or the Project Manager may at any point turn over the egg timer and when it runs out all discussion must cease and another round of poker is played. The structure in the conversation is re-introduced by the soap boxes.
Anchoring can occur if a team estimate is based on discussion alone. A team normally has a mix of conservative and optimistic estimators and there may be people who have agendas.
Developers are likely to want as much time as they can to do the job and the product owner or customer is likely to want it as quickly as possible.