Intro to Project Management: Project Scope Management - WBS Dictionary, Description of Each Element

What This Is

A Work Breakdown Structure (WBS) Dictionary is a detailed description of each element within a project's WBS. It provides a clear understanding of the work required to complete each task, including its scope, deliverables, and any specific requirements. This dictionary is essential for successful project delivery as it ensures that all stakeholders are on the same page and that the project team has a clear understanding of their responsibilities. For example, when building a bridge, the WBS Dictionary would describe each element, such as "Excavate foundation," "Pour concrete," and "Install steel beams," including the specific requirements for each task, such as the type of concrete to use and the beam's dimensions.

Key Terms & Formulas

• WBS Dictionary: A detailed description of each element within a project's WBS.
• Scope Statement: A document that outlines the project's objectives, deliverables, and any specific requirements.
• Deliverables: Specific items or outcomes that must be produced or achieved as part of the project.
• Task Description: A detailed description of the work required to complete a specific task.
• Responsibility Assignment Matrix (RAM): A table that shows which team members are responsible for each task.
• Task Breakdown Structure (TBS): A hierarchical decomposition of tasks into smaller, more manageable components.
• Task Identification: The process of identifying and documenting all tasks required to complete the project.
• Task Estimation: The process of estimating the time, cost, and resources required to complete each task.
• Task Sequencing: The process of determining the order in which tasks should be performed.
• Task Dependencies: The relationships between tasks, including which tasks must be completed before others can begin.
• Critical Path Method (CPM): A method for determining the minimum duration required to complete a project.
• CPM Formula: CPM =? (ai + di) (Critical Path Method = sum of task durations + dependencies)
• ai: Task duration
• di: Dependency duration
• Earned Value (EV): The value of work completed, calculated as EV = % complete × BAC (Earned Value = percent complete times Budget at Completion)
• % complete: The percentage of work completed
• BAC: Budget at Completion

Step-by-Step / Process Flow

1. Identify tasks: Break down the project into smaller, manageable tasks using the WBS.
2. Create task descriptions: Write detailed descriptions of each task, including its scope, deliverables, and any specific requirements.
3. Assign responsibilities: Use a Responsibility Assignment Matrix (RAM) to assign team members to each task.
4. Estimate task duration: Estimate the time required to complete each task.
5. Sequence tasks: Determine the order in which tasks should be performed.
6. Identify dependencies: Determine the relationships between tasks, including which tasks must be completed before others can begin.

Common Mistakes

• Mistake: Failing to create a detailed WBS Dictionary.
• Correction: Ensure that each task has a clear description, including its scope, deliverables, and any specific requirements.
• Mistake: Not assigning responsibilities to team members.
• Correction: Use a Responsibility Assignment Matrix (RAM) to assign team members to each task.
• Mistake: Not estimating task duration accurately.
• Correction: Use historical data, expert judgment, and other techniques to estimate task duration accurately.
• Mistake: Not sequencing tasks correctly.
• Correction: Use a Gantt chart or other scheduling tool to determine the correct sequence of tasks.

Exam Tips

• Tip: Be prepared to answer questions about the WBS Dictionary, including its purpose, content, and application.
• Tip: Understand the difference between a WBS and a Task Breakdown Structure (TBS).
• Tip: Be able to explain the importance of task dependencies and how they impact the project schedule.

Quick Practice Questions

1. If the CPI is 0.8, is the project under or over budget?
2. Answer: Under budget
3. Explanation: CPI (Cost Performance Index) is calculated as EV / AC (Earned Value / Actual Cost). A CPI of 0.8 indicates that the project is under budget.
4. What is the purpose of a WBS Dictionary?
5. Answer: To provide a detailed description of each element within a project's WBS.
6. Explanation: A WBS Dictionary ensures that all stakeholders are on the same page and that the project team has a clear understanding of their responsibilities.
7. What is the difference between a WBS and a Task Breakdown Structure (TBS)?
8. Answer: A WBS is a hierarchical decomposition of the project into smaller, more manageable components, while a TBS is a hierarchical decomposition of tasks into smaller, more manageable components.
9. Explanation: A WBS focuses on the project scope, while a TBS focuses on the tasks required to complete the project.

Last-Minute Cram Sheet

• WBS Dictionary: A detailed description of each element within a project's WBS.
• Scope Statement: A document that outlines the project's objectives, deliverables, and any specific requirements.
• Deliverables: Specific items or outcomes that must be produced or achieved as part of the project.
• Task Description: A detailed description of the work required to complete a specific task.
• Responsibility Assignment Matrix (RAM): A table that shows which team members are responsible for each task.
• Task Breakdown Structure (TBS): A hierarchical decomposition of tasks into smaller, more manageable components.
• Task Identification: The process of identifying and documenting all tasks required to complete the project.
• Task Estimation: The process of estimating the time, cost, and resources required to complete each task.
• Task Sequencing: The process of determining the order in which tasks should be performed.
• Task Dependencies: The relationships between tasks, including which tasks must be completed before others can begin.
• Critical Path Method (CPM): A method for determining the minimum duration required to complete a project.
• CPM Formula: CPM =? (ai + di) (Critical Path Method = sum of task durations + dependencies)
• Earned Value (EV): The value of work completed, calculated as EV = % complete × BAC (Earned Value = percent complete times Budget at Completion)
• 'Decomposition' breaks down work, not activities – it creates the WBS, not the activity list.
• A WBS is not a task list – it's a hierarchical decomposition of the project scope.