There are 2 types of releases  :

• end date driven release. The goal is to be on production or available to end users before a deadline.
• feature driven release. The list of requirements est known and release will end when all of the requirements will be implemented.

Success criterias depends on release type.

Estimation is performed per item. It's best to work on most important items first.

Estimation is performed by the team.

The unit of measure used for estimations is commonly the point. The range of values is picked from the Fibonacci Numbers: 1, 2, 3, 5, 8 and 13.

Estimation techniques are preferably based on a collective estimation approach. "Planning Poker" should be the rule of game and also working with analogies by comparing estimated items works well.

Historically in Scrum, a sprint length is 30 days. However, it is possible, and even recommended to make shorted sprints. Length depends on the project and its constraints.

Ideally, the team should yet have worked together on a project so its actual Velocity should be yet known. This value would then be used for this release, eventually adjusted to the nature of the project. Attention however as a point hasn't necessarily the same value across different projects.

If it's not the case, velocity must be estimated. The best way is to work on the first sprint's content and figure what the team thinks being able to implement during this first sprint. This gives a velocity estimation which can be used for the release planning. Then, planning will be based on velocity measured during previous sprints.

With the following parameters:

• each item estimation,
• items prioritization,
• estimated velocity for the release,

items are affected to sprints of the release.

It is normal to adjust, i.e. to slightly change items prioritization, so the velocity can be the most accurate.

Items must be associated to the first sprints (2 or 3 first ones), but it is not required to do it for all sprints of the release at first.