Time boxed to 8 hours - two segments of 4 hours each
1st is to select Product Backlog for the sprint
2nd is for the Sprint Backlog

Attendees

• ScrumMaster
• Product Owner
• Team
• Chickens - Additional parties can be invited and attend, but as they have no vested interest and have taken on no responsibilities for the project their comments have no weight. Useful for domain info or technical info providers. Dismissed from the meeting after they've disseminated, no chicken observers.
• Product Owners must prepare the Product Backlog prior to the meeting
• In the absence of Product Owner or Product Backlog, ScrumMaster is required to prepare Product Backlog and stand in as Product Owner.

First segment

• Goal: The Team selects those product Backlog items that it believes it can implement successfully. Functionality is to be demonstrated to the Product Owner and Stakeholders at the end of the Sprint.
• Team can make suggestions, but ultimate decision of what comprises the Sprint's Product Backlog is determined by the Product Owner.
• Team is responsible for determining how much of the Product Backlog is addressed during the Sprint. ie Which features can be successfully implemented.
• Time Boxing the Product Backlog analysis segment to 4 hours -- and no more -- forces further analysis to the Team during the Sprint. Large-grained, high priority misunderstood Product Backlog with imprecise estimates can make the Team unable to complete the Product Backlog that it selects, So, small-grained, well understood Product Backlog selections are a better route. This also minimizes the 'design' phase of a project that ends up being wasted due to inevitable changes during development. Efficiency is gained as the illusion of control is put into it's proper place. Hubris no longer is the rule of the 'architect'. Hierarchical development belongs in the past.

Second segment

• Goal: Team figures out how to implement, from the Product Backlog, the selected increment of potentially shippable functionality
• Begins immediately after the first and is Time Boxed to 4 hours.
• Teams acts solely on it's own and without direction from external parties.
• Owner and ScrumMaster must be available to answer questions and only answer questions or observe.
• Output of this meeting is a Sprint Backlog. A list of tasks, task estimates and assignments. It need not be complete, but it must be complete enough to reflect the Team's mutual commitment to the Sprint Backlog and can generate momentum into the Sprint. Allowing work to be accomplished, while more tasks can be developed and implemented by the Team.

Summary

The Sprint Planning meeting enables the Team, ScrumMaster and Product Owner to address the slippery realities of complex, open-ended project development. Strict Time Boxing of the meeting and strong focus on the output generated, result in resources being assigned efficiently to produce high quality code.