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Whether it is team developed a product or develop a particular project, we need to answer, "we will probably be able to complete what time?", Or to a certain point in time, we can do what extent, and therefore the traditional development model, we we need to do what we need to estimate the workload before the work starts.
As opposed to the traditional way of workload estimates, agile estimate has the following characteristics:
- Collective team estimates
Scrum development process, the team shared responsibility and collective commitment to the work of each Sprint, so for agile teams to estimate the workload estimation using the collective way. Collective estimate, usually used as a tool to estimate poker, team collectively estimated by estimating play the game. Poker do using the estimated workload estimate is the most effective, but also very interesting way of an estimate. Poker estimated by a similar set of numbers Fibonacci sequence composition, these figures include: 0,0.5,1,2,3,5,8,20,40,, ∞, each piece of poker there are four sets of such numbers? for 4 personal use.
Estimated using the method of Poker:
- Each team member got a deck of cards, including 0,0.5,1,2,3,5,8,13,20,40,?, ∞, a total of 12.
- Product Owner or team members to play the role of the reader, he is responsible for reading the entries need to estimate the Product Backlog, and ask if you have questions.
- Team discuss this entry.
- When the team understands this entry, each team member is given in accordance with their own ideas estimates, and select the corresponding poker cards, estimates can not tell other people, when digital cards face down button on the desktop.
- After all the cards, the reader to make sure we estimates have been identified, confirmed the number of "1,2,3", we estimate the same time to show results.
- Team evaluated different estimates. Are we the same idea? Do we disagree? Is there anything I have not taken into account? Following the discussion can then estimate the round, the final team needs to reach an agreement.
- Back to the second step, the estimated starting next entry.
Watch Scrum Chinese micro-channel public network number can be obtained estimation micro-channel version of poker.
2. Estimate the size, rather than the estimated time period, using relative estimates, rather than absolute estimates
Bottle of mineral water, so that a 3-year-old sister finish it and the time it takes an adult to finish it the time spent is certainly not the same, so the same job, people with different abilities time it takes to complete It is clearly not the same. If we want to estimate how many kilometers when the absolute distance from home to the company, you may not necessarily know, but if you do the subway to work, the number of stations from home to the company, you must be very easy to know when we know how many stations after , we can probably clear the way how long it takes. When quick estimate, and we will not estimate the absolute time period, we estimate the size, and relative value, which is a multiple of. When agile estimation, we use the story as a unit of measurement points, it is a factor, we believe that we will try to find a minimum size of a function as a reference base, defined as a story point, the other story and compare it to do, If it is twice the size, is the story of two points, if it is five times the size, it is the story of five points.
3. Record each Sprint team speed
Scrum is a team rate team in a Sprint actual story points done by the team rate can know how fast the team to do. Start of new projects or product development, or a new team, there is no initial velocity, we can do a speed of 1-2 Sprint estimates, as the initial speed. Sprint in the course of implementation, we have to record the speed of each Sprint, a reference for future programs.
We estimate the total number of story points Product Backlog, and then they know each Sprint team's average speed, then we can calculate how many Sprint we probably need to be done, so we get the cycle.
