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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

  1. Determine the start and end date for the project or project phase.
  2. Based upon the total project timeline duration, allocate Time Boxes for project tasks or task groups.  
  3. 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.
  4. Individuals start work on the task as soon as the Time Box starts.
  5. Individuals work on the task or task group until the amount of time in the Time Box expires.
  6. 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.  
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  • 00:04 Hello again, I'm Ray Sheen.
  • 00:06 And I'd like to discuss with you an estimating technique for
  • 00:10 projects called time boxes. >> The Time Box estimate is
  • 00:15 an estimate that goes against most projects estimating rules.
  • 00:19 Normally, project estimates start with a scope definition for the activity.
  • 00:23 And that is the controlling factor for creating the estimate.
  • 00:26 Once the activity is defined, an estimate is made for how much time or
  • 00:30 money is required to do the work.
  • 00:32 In a Time Box estimate, the estimating process starts with a given time for
  • 00:37 a type of activity.
  • 00:38 The estimate would determine how much work can be accomplished in that time.
  • 00:43 So the time is actually fixed and it is the scope that is estimated.
  • 00:48 Based upon available resources, the amount of scope or
  • 00:50 work that can be accomplished in that much time can is estimated.
  • 00:54 If the amount of resource available during that time changes,
  • 00:57 the scope estimate changes but the time stays fixed.
  • 01:02 Let's see how to create Time Box estimates.
  • 01:04 We start by determining whether a Time Box estimate is appropriate.
  • 01:08 They are typically used on projects that are very urgent
  • 01:11 possibly in a crisis state.
  • 01:13 Because of that we must make decisions quickly to contain or control a crisis.
  • 01:18 We might not be able to do everything we would like to do but
  • 01:20 we need to start doing something and we need to do that as fast as possible.
  • 01:25 Because there is limited time to act, we create a rough outline of the work and
  • 01:29 set the start and end points for
  • 01:30 the major task activities, based upon when we will need to make decisions.
  • 01:34 We then determine who's available to do project activities.
  • 01:38 These individuals are assigned to tasks and
  • 01:40 they create an estimate of how much work they can accomplish during that time.
  • 01:44 The specific scope deliverables and acceptance criteria for
  • 01:47 that project task remains uncertain.
  • 01:50 You won't know exactly what you'll have until you get to the end of the time box.
  • 01:55 At that point, a judgment call will be made as to whether it's acceptable or not.
  • 02:00 Scope, in this case, is the variable.
  • 02:02 Not time, not money.
  • 02:05 That is the estimating aspect of Time Boxes.
  • 02:07 There are some important principle to follow when using Time Boxes to actually
  • 02:11 accomplish a project goals.
  • 02:13 When the time window opens for a Time Box,
  • 02:15 the team member who is supposed to be doing that work must start immediately.
  • 02:20 During the Time Box,
  • 02:21 they have the freedom to shift the task work around within the Time Box.
  • 02:24 And choose the best way to accomplish the task.
  • 02:27 They've being delegated the authority to manage the work as they think best.
  • 02:31 Also during the Time Box,
  • 02:32 the individual assigned to the task should be full time dedicated to that activity.
  • 02:36 At the end of the Time Box, the task activity stops.
  • 02:40 An assessment is made whether the result that has been achieved at that point is
  • 02:44 good enough to proceed to the next activity.
  • 02:47 Normally, the people doing the Time Box activity know what's required for
  • 02:50 the next activity.
  • 02:51 So they're striving to achieve an acceptable result
  • 02:54 by the end of the Time Box.
  • 02:56 Timebox estimates limit the amount of time a team member will spend on an activity.
  • 03:01 If they run into problems, the Time Box assures that the work doesn't spiral
  • 03:05 out of control and become something far larger than ever expected,
  • 03:09 without coming to a stopping point and a formal decision made to continue.
  • 03:13 Also, the team will not pull into the analysis paralysis trap if they come
  • 03:18 up against a hurdle that they can't overcome.
  • 03:20 Because of the Time Box, they have to come back and
  • 03:23 talk to the rest of the team about the problem when the Time Box ends.
  • 03:26 They cannot extend it.
  • 03:29 Using Time Box estimates and Time Box scheduling,
  • 03:32 it's an excellent method for managing crisis projects or adaptive projects.
  • 03:37 It accounts for the uncertainty that often exists on those types of projects,
  • 03:42 and yet still allows the team to get moving quickly in the execution phase
  • 03:47 of a crisis project.

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