Project Management: Work Breakdown Structure

Successful project management relies on thorough planning.  The more detailed and focused your project plannning is, the more accurate your estimates are and the more manageable your project.  The work breakdown structure (WBS) is a project management deliverable that decomposes the project into smaller components.  It provides the foundation for defining work as it relates to project objectives.  It groups a project's work elements in a way that helps organize and define the total work scope of the project. 


The WBS is used in project as follows:

• To define the project’s scope of work in terms of deliverables and to further decompose those deliverables into specific work components (which facilitates tasks such as estimating, scheduling and resource allocation)
• To provide the project management team with a framework on which to base project status and progress reports
• To facilitate communication between the project manager and stakeholders, as it can be used a communication tool regarding project scope  
• To be used as a critical input to other project management processes such as: schedule network diagrams, activity definitions, project schedules, performance reports

The work breakdown is structured in the form of a tree, which shows a subdivision of effort required to achieve an objective.  The WBS is developed by starting with the end objective and successively subdividing it into manageable components in terms of size, duration, and responsibility, which include all steps necessary to achieve the objective.  Below is an example of WBS for building a car.  As you can see, the ultimate goal -- the car -- sits atop the WBS, while the individual components that go into making the car, sit underneath. 

A WBS permits the aggregation of subordinate costs for tasks, materials, etc., into their successively higher level “parent” tasks, materials, etc. For each element of the work breakdown structure, a description of the task to be performed is generated.


The WBS is organized around the primary products of the project (or planned outcomes).  Since the planned outcomes are the desired ends of the project (i.e. the car), they form a relatively stable set of categories in which the costs of the planned tasks needed to achieve them can be collected.

Project Management: Earned Value Management

Feedback is critical to the success of any project. Timely and targeted feedback can enable project managers to identify problems early and make adjustments that can keep the project on time and on budget.

Earned Value Management (EVM) is a project management technique for measuring project performance and progress in an objective manner. It combines the measurements of scope, time and budget (the triple constraint) into a single integrated system. EVM has proven itself to be one of the most effective project performance measurement and feedback tools. EVM has been called “management with the lights on” because it can help clearly and objectively illuminate where a project is and where it’s going. EVM uses the fundamental principle that patterns and trends in the past can be good predictors of the future.

EVM plays a critical role in helping management answer the following questions about the progress of their project(s): 

• Are we ahead or behind of schedule?
• Are we ahead of behind on budget?
• How efficiently are we using our time?
• When is the project likely to be completed?
• What is the remaining work likely to cost?

EVM not only measures where we are (and where we are likely to go), but also helps the project manager to identify: 

• Where problems are occurring
• Whether the problems are critical or not
• What it will take to get the project back on track

EVM relies on 4 basic data points:

• Planned Value (PV) - describes how far along project work is supposed to be at any point in time (i.e. the projected cost baseline for the project)
• Earned Value (EV) - the snapshot of work progress at a given point in time
• Actual Cost (ACWS) - an indication of the level of resources that have been expended to achieve the actual work performed to date
• % complete - measured in total project hours/hours already worked

EVM is measured in relation to schedule and cost:

• Schedule performance index - measures whether the project is behind or ahead of schedule
• Cost performance index - measures whether the project is behind or ahead of budget

CALCULATIONS

• EV = PV * % complete  
• CPI = EV/AC (>1 means you're below budget)
• SPI = EV/PV (>1 means ahead of schedule)

Project Management: The Triple Constraint

Like any human undertaking, projects need to be performed and delivered under certain constraints.  We must be successful in delivering on project scope given a finite amount of time, under a certain budget, and with a limited amount of human and technical resources.  


Traditionally, these constraints have been listed as "scope," "time," and "cost”.  These are also referred to as the project management triangle, where each side of a triangle represents a constraint. One side of the triangle cannot be changed without affecting the others. A further refinement of the constraints separates product "quality" or "performance" from scope, and turns quality into a fourth constraint.

• The time constraint refers to the amount of time available to complete a project
• The cost constraint refers to the budgeted amount available for the project
• The scope constraint refers to what must be done to produce the project's end result

These three constraints are used to illustrate that project management success is measured by the project team's ability to manage the project, so that the expected results are produced while managing time and cost.  


These three constraints are often competing constraints: increased scope typically means increased time and increased cost, a tight time constraint could mean increased costs and reduced scope, and a tight budget could mean increased time and reduced scope.  If there is a requirement to shift any one of these factors then at least one of the other factors must also be manipulated.


One of the first tasks a project manager of a brand new project is faced with is the prioritization of the Triple Constraint. This can only be done by communicating with the client. Whether the client understands project management or has ever heard of the Triple Constraint, in their mind, they already know what is most important to them. They may require that the project be completed within a certain timeframe, no matter the costs.  Or, they may require that the project stay under budget, no matter how long it takes to accomplish.  And, typically, the client requires that the project finish on time and within budget, delivering on all the scope and quality aspects set forth in the project charter.  Your job, as project manager, is to find this out, and to manage to these priorities.