During schedule planning you decompose large work packages into smaller, more manageable activities in your work breakdown structure. This illustrates the hierarchical nature of the WBS. Which feature of a WBS hierarchy does this best demonstrate?

Introduction / Context:
The work breakdown structure, or WBS, is a hierarchical decomposition of the total scope of work to be carried out by the project team. Understanding how this hierarchy behaves helps the project manager communicate with different stakeholders and plan effectively. The question links decomposition of tasks to an important feature of WBS hierarchy.

Given Data / Assumptions:
- Large tasks or work packages are decomposed into smaller activities. - The WBS is organized hierarchically, from high level deliverables down to detailed work. - The focus is on a feature that arises from this hierarchical nature. - The question is based on standard WBS concepts from project management practice.

Concept / Approach:
A WBS hierarchy allows information to be viewed at different levels of detail. Senior management might only need to see top level deliverables, while the project team needs detailed tasks. Because of the tree structure, lower level elements can be summarized or rolled up into higher level nodes. This ability to expand or collapse the view is a core feature of hierarchical structures and is frequently mentioned in WBS descriptions as a key benefit for reporting and control.

Step-by-Step Solution:
Step 1: Identify that decomposition into smaller activities is what creates multiple levels in the WBS. Step 2: Recall that a hierarchy lets you aggregate lower level estimates and progress into higher level summaries. Step 3: Review the options and look for the one that explicitly mentions rolling up or collapsing information. Step 4: Recognize that the ability to present information at the appropriate level for each audience is a direct result of the hierarchical structure.

Verification / Alternative check:
Another way to check is to think about reports. A project sponsor may receive a report that shows only level 2 of the WBS, while the project manager tracks level 4 activities. Both views come from the same hierarchy by collapsing or expanding nodes. This confirms that the feature being tested is the flexibility to roll up or drill down, not limitations on depth or elimination of other tools.

Why Other Options Are Wrong:
Option A is wrong because a WBS can reduce duplication but does not guarantee complete prevention; careful definition and control are still required. Option C is wrong because while decomposition does support detailed planning, this is not specifically the feature of the hierarchy that the question highlights. Option D is wrong because there is no rule that limits a WBS to exactly three levels; the depth should reflect the needed level of control. Option E is wrong because a WBS does not replace the network diagram; both tools serve different but complementary purposes.

Common Pitfalls:
A common mistake is to believe that the primary purpose of a WBS is to list tasks rather than deliverables. Another pitfall is assuming that there are fixed rules about the number of levels or that a well structured WBS automatically removes all duplication. Learners also sometimes confuse the WBS with the schedule, forgetting that the WBS feeds the schedule but does not itself show sequencing or dependencies.

Final Answer:
The feature being described is that a WBS hierarchy can be rolled up or collapsed to show the right level of detail for each audience.