Intro to Project Management: Project Scope Management Work Breakdown Structure WBS Decomposition DeliverableOriented 100 Rule

What This Is

A Work Breakdown Structure (WBS) is a hierarchical decomposition of the project scope into manageable tasks. It's essential for successful project delivery as it helps ensure all work is accounted for, reduces misunderstandings, and facilitates communication among stakeholders. Imagine building a new house: a WBS would break down the project into tasks like "excavate foundation," "frame walls," and "install electrical systems."

Key Terms & Formulas

• WBS (Work Breakdown Structure): A hierarchical decomposition of the project scope into manageable tasks.
• Deliverable-Oriented WBS: Focuses on specific deliverables or outcomes, such as "design a logo" or "develop a software module."
• 100% Rule: The WBS must account for 100% of the project scope, with no gaps or overlaps.
• Decomposition: Breaking down a task into smaller, more manageable tasks.
• Scope Statement: A document that outlines the project scope, including the WBS.
• Task: A specific, actionable work item within the WBS.
• Activity: A task with a specific start and end date.
• Level of Detail (LOD): The level of detail in the WBS, ranging from high-level to low-level.
• WBS Code: A unique identifier assigned to each task or activity in the WBS.
• EV = % complete × BAC (Earned Value = percent complete times Budget at Completion): Calculates the earned value of completed work.
• CPI (Cost Performance Index) = EV ÷ AC (Cost Performance Index = Earned Value ÷ Actual Cost): Measures the project's cost performance.

Step-by-Step / Process Flow

1. Develop the Scope Statement: Define the project scope, including the WBS, with stakeholders.
2. Decompose the Scope: Break down the project scope into smaller, more manageable tasks using decomposition techniques like mind mapping or flowcharts.
3. Create the WBS: Organize the decomposed tasks into a hierarchical structure, using a WBS code to identify each task.
4. Verify the 100% Rule: Ensure the WBS accounts for 100% of the project scope, with no gaps or overlaps.
5. Refine the WBS: Review and refine the WBS with stakeholders to ensure it's accurate and complete.

Common Mistakes

• Mistake: Failing to account for 100% of the project scope in the WBS.
  Correction: Verify the 100% rule by reviewing the WBS with stakeholders and ensuring all tasks are included.
• Mistake: Using a WBS that's too high-level or too low-level.
  Correction: Use a level of detail that's appropriate for the project, and refine the WBS as needed.
• Mistake: Not involving stakeholders in the WBS development process.
  Correction: Engage stakeholders throughout the WBS development process to ensure their input and buy-in.

Exam Tips

• Tip: Be prepared to explain the difference between a WBS and an activity list.
• Tip: Understand the importance of decomposition in creating a WBS.
• Tip: Be able to calculate earned value and cost performance index.

Quick Practice Questions

1. If the CPI is 0.8, is the project under or over budget? Answer: Under budget. Explanation: A CPI of 0.8 indicates the project is earning 80% of its budgeted value, which means it's under budget.
2. If the EV is $100,000 and the BAC is $200,000, what is the percent complete? Answer: 50%. Explanation: Using the formula EV = % complete × BAC, we can calculate the percent complete as EV ÷ BAC = $100,000 ÷ $200,000 = 0.5 or 50%.
3. If the WBS is missing a critical task, what is the impact on the project? Answer: The project scope is incomplete, and the project may be at risk. Explanation: A missing task in the WBS means the project scope is not fully accounted for, which can lead to scope creep, delays, and cost overruns.

Last-Minute Cram Sheet

• A WBS is a hierarchical decomposition of the project scope into manageable tasks.
• Decomposition breaks down work, not activities – it creates the WBS, not the activity list.
• The 100% rule ensures the WBS accounts for 100% of the project scope.
• EV = % complete × BAC calculates the earned value of completed work.
• CPI = EV ÷ AC measures the project's cost performance.
• A WBS code is a unique identifier assigned to each task or activity in the WBS.
• Scope creep occurs when the project scope changes without proper authorization.
• A level of detail (LOD) is the level of detail in the WBS, ranging from high-level to low-level.
• A task is a specific, actionable work item within the WBS.
• An activity is a task with a specific start and end date.
• ⚠️ A WBS that's too high-level or too low-level can lead to scope creep and project delays.