Chapter 6 - The WBS and Project Estimation Flashcards
. What is a WBS? What purpose does it serve?
The WBS represents a logical decomposition of the work to be performed and focuses on how the product, service, or result is naturally subdivided. It is an outline of what work is to be performed. In short, the WBS provides an outline for all of the work the project team will perform.
Discuss why a project’s scope must be tied to the WBS
The total scope of the project is divided and subdivided into specific deliverables that can be more easily managed. This includes both product and project-oriented deliverables. This outline IS the WBS
What is a work package?
The WBS decomposes the project into smaller components and more manageable units of work called work packages. Work packages provide a logical basis for defining the
project activities and assigning resources to those activities so that all the project work is identified. A work package makes it possible to develop a project plan, schedule,
and budget and then later monitor the project’s progress
What is the difference between a deliverable and a milestone?
Deliverables and milestones are closely related, but they are not the same thing. Deliverables
can include such things as presentations or reports, plans, prototypes, and the final application
system. A milestone, on the other hand, must focus on an achievement. A milestone provides evidence that that deliverable has been completed or that a phase is formally over.
For example, a deliverable may be a prototype of the user interface, but the milestone would be a stakeholder’s formal acceptance of the user interface. Only the formal acceptance or approval of the user interface by the project sponsor would allow the project team to move on to the next phase of the project.
What purpose do milestones serve?
Milestones provide evidence that a deliverable has been completed. (Formal acceptance).
What are some advantages of including milestones in the WBS?
First, milestones can keep the project team focused. On the other hand, if milestones are realistic, they can motivate a project team if their attainment is viewed as a success. Milestones also reduce the risk of a project. The passing of a milestone, especially a phase milestone, should provide an opportunity to review the progress of the project. Milestones can also provide a mechanism for quality control.
What is the proper level of detail for a WBS?
Therefore, the
level of detail should support not only the development of the project plan but allow the project
manager and project team to monitor and compare the project’s actual progress to the original
plan’s schedule and budget. The two most common errors when developing a WBS are too
little or too much detail. Too little detail may result in a project plan that overlooks and omits
important activities and tasks. This will lead to an overly optimistic schedule and budget. On the
other hand, the WBS should not be a to-do list of one-hour tasks.
Why should the WBS be deliverable-oriented?
the focus of a project should be to
produce something, not merely on completing a specified number of activities. Although the
WBS does not provide for any explicit looping, some activities may have to be repeated until
the milestone is achieved.
Explain why people who do the work on a project should be involved in developing the project plan?
A person who has experience and expertise in
a particular area probably has a better feel for what activities need to be performed in order
to produce a particular project deliverable. Although the project manager is responsible for
ensuring that a realistic WBS is developed, the people who must carry out the activities and
tasks may be more committed to the plan if they are involved in its development.
What makes estimating an IT project challenging?
Since a resource generally performs a particular task, a cost associated with that
particular resource must be allocated as part of the time it takes to complete that task. The time
estimated to complete a particular task will have a direct bearing on the project’s budget as
wel
What is guesstimating? Why should a project manager not rely on this technique for estimating a project?
guesstimate, or guess at the estimates, because it is quick and easy. People are often overly optimistic and, therefore, their guesstimates are overly optimistic.
Underestimating can result in long hours, reduced quality, and unmet client expectations.
What is time boxing? What are some advantages and disadvantages of time boxing project activities?
Time boxing is a technique whereby a box of time is allocated for a specific activity or task. Used effectively, time boxing can help focus the project team’s effort on an important and
critical task. The schedule pressure to meet a particular deadline, however, may result in long
hours and pressure to succeed. Used inappropriately or too often, the project team members
become burned out and frustrated.
Describe top-down estimating. What are some advantages and disadvantages of top-down estimating?
Top-down estimating involves estimating the schedule and/or cost of the entire project in terms
of how long it should take or how much it should cost. Top-down estimating is a very common
occurrence that often results from a mandate made by upper management.
Once the target objectives in terms of schedule or budget are identified, it is up to the project
manager to allocate percentages to the various project life cycle phases and associated tasks or
activities. Data from past projects can be very useful in applying percentages and ensuring that
the estimates are reasonable. It is important to keep in mind that top-down estimating works
well when the target objectives are reasonable, realistic, and achievable.When made by people independent from the project team, however, these targets are often
overly optimistic or overly aggressive.
Describe bottom-up estimating. What are some advantages and disadvantages of bottom-up estimating?
Bottom-up
estimating involves dividing the project into smaller modules and then directly estimating the
time and effort in terms of person-hours, person-weeks, or person-months for each module. The
work breakdown structure provides the basis for bottom-up estimating because all of the project
phases and activities are defined.
Although bottom-up
estimating is straightforward, confusing effort with progress can be problematic How did we come up with these estimates? Did we guesstimate them?These estimates could be based on experience—the software testers may have
done these activities many times in the past so they know what activities have to be done and
how long each activity will take. Or, these estimates could be based on similar or analogous
projects.
Discuss why adding people to a project that is already behind schedule can make it later?
Time needed to train and assimilate new people into the project may outweigh the benefits of having more people work on it.
It may not be possible to work on more tasks at the same time due to dependency (critical path)
