Work Breakdown Structures
what the doctor say:
Work Breakdown Structures (WBS) give us an important framework for the system on which we are working. It has many important functions. A Work Breakdown Structure (WBS) is a decomposition of all the work necessary to complete a project. A WBS is arranged in a hierarchy and constructed to allow for clear and logical groupings, either by all program activities (includes program management functions and systems engineering) or just the product itself.
These are some of the benefits of a WBS:
Provides a solid foundation for planning and scheduling.
Breaks down projects into manageable work packages.
Provides a way to estimate project costs accurately.
Makes sure no important deliverables are forgotten.
Helps project managers with resource allocation (people, places and dollars).
Provides an ideal tool for team brainstorming and for promoting team cohesion
STUDENT LEARNING OUTCOMES
Once you have finished this topic you should be able to:
Define a Work Breakdown Structure
Create a third level WBS for the system in your case analysis
Define the 100% rule of WBS
ASSIGNMENTS
Download the Power Point file Word breakdown structure and view the lecture in class.
Write a one page paper on the importance and uses of the Work Breakdown Structure
Work Breakdown Structures (WBS)
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WBS
Technique originally developed by financial specialists to
track spent money on a program or track the anticipated a need
to spend money
A control mechanism to make sure project cost estimates
covered everything
A control mechanism to make sure they understood where
all the money went or was going
This mechanism has been appropriated by project engineers
and system engineers to make sure that all effort required for
program or project has been accounted for and tracked
A great way to find out if a project is in trouble when the
actual effort projected in area of the WBS is exceeding
projections
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What is a WBS ?
A Work Breakdown Structure (WBS) is a fundamental project management tool for defining and organizing the total scope of a project, using a hierarchical tree structure.
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What’s a WBS ?
A hierarchical breakdown (level 1 thru n) of the
work to be executed by the program team
Typically in a tree format
The first two levels of the WBS (Level 1 and Level 2) define a set of planned outcomes that collectively and exclusively represent 100% of the project scope.
At each subsequent level, the children of a parent node collectively and exclusively represent 100% of the scope of their parent node.
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What is a WBS ?
A well-designed WBS describes planned outcomes instead of planned actions.
Outcomes are the desired ends of the project, and can be predicted accurately
An easy way to think about a work breakdown
structure is as an outline or map of the specific
program
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WBS Dictionary
A WBS dictionary is a document that has a paragraph
or two describing the technical content of each
element of the WBS
Because WBS element numbering and names can be
cryptic, it is a good way to understand what exactly is
in the WBS
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100% Rule
The 100% Rule...states that the WBS includes 100% of the work defined by the project scope and captures all deliverables – internal, external, interim – in terms of the work to be completed, including project management (and systems engineering).
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100% Rule
The 100% rule is one of the most important principles guiding the development, decomposition and evaluation of the WBS.
The rule applies at all levels within the hierarchy: the sum of the work at the “child” level must equal 100% of the work represented by the “parent” and the WBS should not include any work that falls outside the actual scope of the project, that is, it cannot include more than 100% of the work…
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100% Rule Example
Project
Part A Part B
Part A.1 Part A.2 Part B.1 Part B.2 Part B.3
Parts A and B must add
up to 100% of the work
of the project
Parts B.1, B.2
and B.3 must
add up to 100%
of the work in
Part B
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Figure 1: WBS Construction Technique. This
exemplary WBS is from PMI's Practice Standard for
Work Breakdown Structures (2nd Edition).
SE may or may not be included
In project management
http://upload.wikimedia.org/wikipedia/en/e/e4/WbsConstruction.png
http://en.wikipedia.org/wiki/Image:WbsConstruction.png
http://en.wikipedia.org/wiki/Image:WbsConstruction.png
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Examples of WBS
Product WBS
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WBS Levels for SOFIA
• Project (or System level) - integrating all of the
systems of the project
• Observatory System (Subsystem) – integrating all of
the parts of the observatory – instruments and facility
• Airborne Facility (Segment level) – integrating all of
the parts on the aircraft
• Telescope Element (Element level) - Integrating the
parts of the telescope
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Note – Systems
Engineering at
4 different levels
Project - integrating all
of the systems of the
project
Observatory System –
integrating all of the
parts of the observatory
– instruments and
facility
Airborne Facility
Segment – integrating
all of the parts on the
aircraft
Telescope Element
- integrating the parts
of the telescope
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Why is a WBS Important to a Systems Engineer ?
1. Budgeting: The proper way to get effort budgeted in a big
project is to get it into the WBS – so if you want systems
engineering to have a budget, need to understand the WBS
2. Systems Engineering View: effort may exist at many
levels in the project, examining the WBS allows you to see
where you need to insert Systems Engineering efforts
3. Integration View: If Systems Engineering is going to
integrate a project, it needs to know what is going on. The
budgeted effort is reflected in a WBS. The WBS is the place
to see where effort is being expended that may require
integration.
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Why is a WBS Important to a Systems Engineer ?
4. Technical Performance Budgeting: It is a good place to start for building technical performance budgets, like weight, electrical power, pointing accuracy
5. Cost Estimating and Scheduling: Systems Engineers are always heavily involved in cost estimating and scheduling and the WBS is a good tool for both of these efforts
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Rules for WBS
A WBS is not a project plan nor a project schedule and it is not a chronological listing. It is considered poor practice to construct a project schedule before
designing a proper WBS.
This would be similar to scheduling the activities of home construction before completing the house design.
Without concentrating on planned outcomes, it is very difficult to follow the 100% Rule at all levels of the WBS hierarchy.
A WBS is not an organizational hierarchy. Some practitioners make the mistake of creating a WBS that shadows
the organizational chart.
While it is common for responsibility to be assigned to organizational elements, a WBS that shadows the organizational structure is not descriptive of the project scope and is not outcome-oriented.
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Rules for WBS
WBS updates, other than progressive elaboration of details, require formal change control.
This is another reason why a WBS should be outcome-oriented and not be prescriptive of methods.
Methods can, and do, change frequently, but changes in planned outcomes require a higher degree of formality.
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Once you have the WBS
If you make each element a row in a spreadsheet
Don’t forgot the non-hardware items such as software, analysis, test, integration and project management
And make each column the appropriate unit of time (month, year) that you use for accounting/budgeting
Then you can fill in each cell with your method for estimating cost for that item for that year
Called a Cost Estimating Relationship (CER)
CER’s can also include the escalation due to inflation
Then if you sum columns, you get yearly budget
If you sum rows, you get total estimated cost for each item in the WBS
Once you have a WBS, you have the elements to build a schedule
There should be a schedule with milestones for every item in the WBS
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Cost Estimation Relationship - Example
Jan Feb Mar Apr May Total
Planning $500 $500 $500 $300 $100 $2,100
Dinner $100 $100 $100 $100 $7,000 $7,400
Room $0 $0 $1,500 $4,000 $500 $6,000
Guests $100 $100 $100 $100 $100 $500
Staff $100 $100 $100 $100 $2,000 $2,400
Speakers $100 $100 $100 $3,000 $100 $3,400
Total $900 $900 $2,400 $7,600 $9,800 $21,800
Banquet is scheduled for May 15th
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$6,000
$500
$2,400 $3.000
Why Use a WBS
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• The work breakdown structure has a number of
benefits in addition to defining and organizing the
project work.
• A project budget can be allocated to the top levels of
the work breakdown structure, and department budgets
can be quickly calculated based on the each project's
work breakdown structure.
• By allocating time and cost estimates to specific
sections of the work breakdown structure, a project
schedule and budget can be quickly developed from the
WBS.
• As the project executes, specific sections of the WBS
can be tracked to identify project cost performance and
identify issues and problem areas in the project.
Why Use a WBS
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• Project WBSs can also be used to identify potential
risks in a given project.
• If a WBS has a branch that is not well defined then it
represents a scope definition risk.
• These risks should be tracked in a project log and
reviewed as the project executes.
• By integrating the WBS with an organizational
breakdown structure, the project manager can also
identify communication points and formulate a
communication plan across the project organization.
Why Use a WBS
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• When a project is falling behind, referring the WBS
will quickly identify the major deliverables impacted
by a failing work package or late sub-deliverable.
• The WBS can also be color coded to represent sub-
deliverable status.
• Assigning colors of red for late, yellow for at risk,
green for on-target, and blue for completed
deliverables is an effective way to produce a heat-map
of project progress and draw management's attention to
key areas of the work breakdown structure.
WBS Guidelines
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• The top level represents the final system deliverable
• Sub-deliverables contain work packages that are assigned to
a organization’s unit
• All elements of the work breakdown structure don’t need to
be defined to the same level
• The work package defines the work, duration, and costs for
the tasks required to produce the sub-deliverable
• Work packages should not exceed an agreed to period
• Work packages should be independent of other work
packages in the work breakdown structure
• Work packages are unique and should not be duplicated
across the work breakdown structure
Homework
For EE 461 Class
As a team, build a Level 3 WBS for you project.
For EE590 and IE590
Write a 1 page paper on the importance of a
Work Breakdown Structure.