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About this lesson
Time Boxes are an estimating technique that sets a finite time for a task or task group. The amount of scope that is completed is variable. Whatever scope is done when the time box ends is the amount of scope for that activity on the project.
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Quick reference
Time Box
Time Boxes are an estimating technique that sets a finite time for a task or task group. The amount of scope that is completed is variable. Whatever scope is done when the time box ends is the amount of scope for that activity on the project.
When to use
Time Boxes are used when estimating project activities where the schedule is the most important constraint and the performance or quality level of the scope can be varied to meet the schedule.
Time Boxes are most often used on Extreme or crisis projects – or projects that are going through a short time of crisis.
Time Boxes are also used in AGILE/Scrum projects as the primary schedule estimating technique at the project level.
Instructions
- Determine the start and end date for the project or project phase.
- Based upon the total project timeline duration, allocate Time Boxes for project tasks or task groups.
- Estimates for the amount of work that can be accomplished by the individuals assigned to the tasks during the time box are generated, usually by the individuals doing the work.
- Individuals start work on the task as soon as the Time Box starts.
- Individuals work on the task or task group until the amount of time in the Time Box expires.
- Whatever level of scope achievement is created during the Time Box is by definition the level that is to be completed on the project.
Hints & tips
- Time Boxes are often considered to be the opposite of traditional project management – where the scope is defined as the project goal and as much time as is needed is used to achieve the goal. With Time Boxes, the schedule is the project goal, and whatever scope is completed is good enough for the project.
- Time Box discipline is critical. Start on time and end at the end of the Time Box.
- It is best to use dedicated resources during the Time Box.
- Keep your Time Boxes for project activities short; a good target is one to two weeks or less.
- 00:04 Hello again, I'm Ray Sheen, and
- 00:06 I'd like to discuss with you an estimating technique for projects called Time Boxes.
- 00:11 The Time Box estimate is a fundamental principle used in Agile Scrum projects.
- 00:16 It's an estimating approach that goes against most project estimating rules.
- 00:21 Normally, project estimates start with the scope definition of an activity, and
- 00:25 that is the controlling factor for creating the estimate.
- 00:28 Once the activity is defined, an estimate is made for how much time or
- 00:33 money is required to do that work.
- 00:35 In a Time Box estimate, the estimate process starts with a given time for
- 00:39 a type of activity.
- 00:41 The estimate will be to determine how much work can be accomplished in that
- 00:46 much time.
- 00:47 So the time is actually fixed, and it's the scope that is variable or estimated.
- 00:51 Based upon available resources, the amount of scope of work that can be accomplished
- 00:56 in that much time is estimated.
- 00:57 If the amount of resources available during that time changes,
- 01:02 the scope estimate changes, but the time stays fixed.
- 01:06 So let's see how to create Time Box estimates.
- 01:09 We start by determining whether a Time Box estimate is appropriate.
- 01:13 They're typically used on an adaptive Agile Scrum project or
- 01:16 projects that are very urgent possibly in a crisis state.
- 01:20 Because of that, we must make decisions quickly to contain or control the crisis.
- 01:25 We might not be able to do everything we'd like to do, but
- 01:28 we need to start doing something and we need to do that as fast as possible.
- 01:32 Whether a crisis project or an Agile project,
- 01:35 we create a rough outline of the work.
- 01:37 In an Agile project, that is the product backlog for a sprint.
- 01:41 Then we set the start and end points for
- 01:43 the major activities based upon what we will need to make decisions.
- 01:47 We then determine who's available to do project activities.
- 01:50 Who's on the Scrum team?
- 01:51 These individuals either select tasks or are assigned tasks,
- 01:55 and they create an estimate of how much work they can accomplish during that time.
- 02:00 The specific scope deliverables and acceptance criteria for
- 02:03 the entire project remain uncertain.
- 02:06 You don't know exactly what you will have until you get to the end of the Time Box.
- 02:10 At that point, you consider what has been accomplished and
- 02:14 make a judgment call as to whether it's acceptable or not.
- 02:18 Scope, in this case, is the variable.
- 02:20 Not time, not money.
- 02:23 That is the estimating aspect of Time Boxes.
- 02:26 There are some important principles to follow when using Time Boxes to actually
- 02:30 accomplish your project goals.
- 02:32 When the time window opens for a Time Box,
- 02:35 the team members who are supposed to be working must start immediately.
- 02:40 During the Time Box, they have the freedom to shift the task work around within
- 02:44 the Time Box, and choose the best way to accomplish that task.
- 02:48 They've been delegated the authority to manage the work as they think best.
- 02:52 They don't need to come back and ask for
- 02:54 permission to do what's already in the Time Box.
- 02:57 Also during the Time Box,
- 02:59 the individual assigned to the task should be full-time dedicated on that activity.
- 03:05 At the end of the Time Box, the task activity stops.
- 03:08 An assessment is made whether the result that has been achieved at that point is
- 03:12 good enough to proceed on to the next activity.
- 03:15 Normally, the person doing the work in the Time Box knows what's required for
- 03:19 the next activity.
- 03:20 So they're striving to achieve an acceptable result by the end of
- 03:23 the Time Box.
- 03:24 Time Box estimates limit the amount of time that team
- 03:27 members will spend on an activity.
- 03:30 If they run into problems, the Time Box assures that the work doesn't spiral
- 03:34 out of control and become something far larger than ever expected without coming
- 03:39 to a stopping point, and a formal decision made to continue.
- 03:43 Also, the team will not fall into analysis paralysis if they come up against a hurdle
- 03:47 that they can't overcome.
- 03:49 Because of the Time Box, they have to come back and
- 03:52 talk to the rest of the team about the problem when the Time Box ends.
- 03:55 They can't unilaterally extend it.
- 03:58 Using Time Box estimates, and Time Box scheduling is an excellent method for
- 04:03 managing crisis projects or adaptive projects.
- 04:06 It accounts for the uncertainty that often exists on those types of projects and
- 04:11 yet still allows the team to get moving quickly
- 04:15 in the execution phase of a crisis project.
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