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CAPES: Schedule Development and Work Breakdown Structure

CAPES · Work through your exam, one topic at a time.

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Schedule Development and Work Breakdown Structure

This domain tests how scope is decomposed into a WBS and then translated into a schedule. The exam expects you to distinguish a deliverable-oriented WBS from an organizational breakdown, apply the 100% rule, and show how work packages become activities with logic, durations, and resources. It also tests schedule basis documentation and the level of detail appropriate to the schedule's purpose.

WBS rules that drive schedule structure

  • The WBS is deliverable-oriented, not department-oriented. An organization breakdown structure (OBS) maps responsibility; the WBS maps scope.
  • The 100% rule: child elements must capture all scope of the parent and no more. Sibling elements should be mutually exclusive to avoid double counting.
  • The lowest WBS element is usually a work package, which can be planned and controlled. The WBS dictionary defines scope, deliverables, acceptance criteria, and boundaries.
  • Activities should trace to a work package. If an activity cannot be mapped, either scope is missing from the WBS or the activity is project overhead.
  • Schedule development uses a hierarchy: summary/master schedule, control schedule, and execution schedule. Rolling-wave planning elaborates near-term work while later work remains at summary level.

Worked example

A pump-station project uses: 1.0 Pump station; 1.1 Design; 1.2 Procurement; 1.3 Construction; 1.4 Commissioning. Construction decomposes into 1.3.1 Civil, 1.3.2 Mechanical, and 1.3.3 Electrical. Work package 1.3.2 includes pump setting and alignment. The scheduler creates activities for procurement, foundations, pump setting, alignment, and testing, each linked to its work package. A test activity that supports all packages is coded to 1.4, not left unmapped. If civil foundations are omitted, the WBS fails the 100% rule even if every existing activity has logic.

Traps that cost marks

Organizing the WBS by department; using phases as a substitute for deliverables; decomposing so finely that activities are below control level; and building an activity list without a WBS. Another trap is treating the WBS dictionary as optional: without it, activity scope and acceptance criteria are ambiguous, and progress claims become disputed.