Archive for April, 2011

Estimate time

Author: admin

Apr 5

Once you are satisfied with the breakdown of tasks, ask: How much time will it take to complete each task?

If a task is familiar—that is, employees have done it many times before—estimating completion time will not be difficult. Unfamiliar tasks, in contrast, require more thought and discussion. Here are a few tips for making time estimates:

  • Using experience. Base estimates on experience, using the average expected time to perform a task. The more familiar you or other employees are with a particular task, the more accurate your estimate will be.
  • Keeping estimates as estimates. Remember that estimates are just that—estimates. They’re not guarantees, so don’t change them into firm commitments quite yet.
  • Clarifying assumptions. When presenting estimates to stakeholders, make sure they are aware of all the assumptions and variables behind those calculations. Consider presenting time factors as ranges instead of fixed estimates. For example, say, “Task A will take eight to twelve hours to complete.” Any fixed estimate is bound to be wrong; a range, on the other hand, is more likely to be right, because it accounts for natural variations.
  • Padding. Padding estimates is an acceptable way of reducing the risk that a task (or the entire project) will take longer than the schedule allows. But apply this practice openly and with full awareness of what you’re doing. For example, if your estimate is based on receiving certain products within a two-week period, make sure that expectation is clear. That way, the project team and stakeholders know there is a chance those products may not arrive on time. Also let them know what the consequences of a late arrival would be.

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Developing High-Level Estimates

Author: admin

Apr 3

Key Idea

Many projects fail either because someone has overlooked a significant part of the work or managers have grossly underestimated the time and money involved. One tool that many project managers find helpful in planning is the Work Breakdown Structure.

The Work Breakdown Structure (WBS) helps you develop estimates, assign personnel, track progress, and show the scope of the project work. With a WBS, you subdivide a complex activity into smaller tasks, continuing until the activity can no longer be subdivided. At that point, you have defined each task in its smallest—and most manageable—unit.

To create a WBS:

  • Ask, “What has to be done to accomplish X?”
  • Continue to ask this question, breaking those tasks into the smallest possible subtasks, until your answer represents a component or task that cannot be subdivided further.
  • Estimate how long it will take to complete each of these tasks and how much each will cost in terms of dollars and person-hours.

When developing a WBS, many managers wonder when to stop subdividing the activities. As a general guideline, stop when you reach the point at which the work will take an amount of time equal to the smallest unit of time you want to schedule. Thus, if you want to schedule to the nearest day, break down the work to the point at which each task takes a day to perform.

A WBS typically consists of three to six levels of subdivided activities. The more complex the project, the more levels the WBS will have. As a general rule, no project should have more than 20 levels—and only an enormous project would have that many.

In the first phase of project management—defining and organizing the project—don’t worry about the sequence in which the project activities are performed. Use the WBS during the first phase only to build a rough framework of activities.

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