WBS Notes and Study Guide

What is a Work Breakdown Structure (WBS)?

  • WBS is the process of defining tasks/activities required to be carried out in a project by describing/defining them into smaller units. This yields a structured vision of what has to be delivered.
  • It is a hierarchical decomposition of the total scope of work to be carried out by the project team to accomplish the project objectives and create the required deliverables. This decomposition enables clearer planning and control of project work.
  • In short, WBS translates the project scope into a structured set of deliverables and work packages that can be planned, scheduled, and managed.

Key Concepts of WBS

  • Decomposition: A technique used for dividing and subdividing the project scope and project deliverables into smaller, more manageable parts. This is fundamental to creating a usable WBS.
  • The purpose/benefit: Provides a structured vision of what has to be delivered and helps organize work into manageable components.
  • WBS levels: Levels 1, 2, 3, etc. Assignment 3 in the material requires Level 3 detail. The depth of the WBS is driven by project needs and reporting requirements.
  • WBS as a planning and sequencing tool: By defining activities and their relationships, one can identify project duration, start times, whether activities can run in parallel, and the overall schedule.
  • WBS can be organized by different criteria, such as:
    • By trade/discipline (e.g., plumbing, electrical, structural)
    • By location/floor (e.g., Ground Floor, 1st Floor, 2nd Floor)
    • A combination of both depending on project needs

Simple Illustration: WBS for a Cup of Tea

  • The material uses a cup of tea to illustrate applying WBS to a simple task. Steps (from the slides):
    1. Pick a cup or mug
    2. Place tea bag in cup
    3. Scoop a teaspoon of sugar into cup
    4. Take milk out of the fridge
    5. Put kettle on
    6. Wait for water to boil
    7. Pour water into the cup
    8. Drink tea
  • This demonstrates how a simple task can be broken down into discrete tasks, showing how WBS creates a roadmap from a high-level outcome to concrete actions.
  • There is a note of a variant: on page 5, the sequence is shown with some steps re-ordered or repeated ("Take 2"), illustrating how WBS can be iteratively refined.

WBS in Construction Context

  • WBS is used to define the total scope of work for a project such as a six-unit classroom block. It organizes major deliverables into a hierarchical framework that can be assigned, scheduled, and tracked.
  • WBS Levels: Levels 1, 2, 3, etc. Level 3 detail is required for certain assignments.
  • Example of decomposition for roofing shows how a complex system can be broken into components (e.g., structural deck, roof coverings, and associated supports) to manage sequencing and responsibilities.
  • The construction sequence will typically follow a pattern regardless of construction method, including steps such as:
    • Assemble and erect formwork
    • Prepare and place reinforcement
    • Pour and compact or vibrate concrete
    • Strike and remove formwork in stages as curing proceeds
  • A formal WBS helps in planning, scheduling, cost estimation, risk management, and progress tracking in construction projects.

Sequencing and Duration

  • By defining activities and their relationships, you can answer key timing questions:
    • When can the first activity start?
    • What is the next activity?
    • What is the duration of each activity?
    • Can any activities be done in parallel?
  • This leads to the creation of sequences, networks, and schedules (e.g., Gantt charts and network diagrams) to model project duration and critical paths.

WBS Levels and Example Scheduling Details

  • WBS Levels: Levels 1, 2, 3, etc. Level 3 is used in Assignment 3 in the material.
  • Example items from a six-unit classroom block (high-level fragments):
    • SUSPENDED SECOND FLOOR
    • Lay & prop truss deck
    • Lay relo to 2nd floor
    • Pump, place & finish 2nd floor slab
    • Reo & shotcrete basement A/C area slab
    • Shotcrete walls to A/C area to basement
    • Form, place & finish 1st to 2nd floor fire stairs
    • Fire rate steelwork
    • SUSPENDED GROUND FLOOR
    • Various activities with dates such as Mon 21/05/07, Fri 25/05/07, etc., and durations like 1–5 days shown on a schedule
  • A note on sequencing in built environments: dates and durations are shown for planning (e.g., day-labeled milestones), and the schedule includes time estimates like 17 days, 40 days, etc., illustrating the scale of construction sequencing.
  • The slides provide a concrete example to connect WBS structure with real-world construction sequences and durations.

Construction Sequencing Framework

  • Regardless of the method of construction, the sequencing pattern remains consistent, with core steps:
    1) Assemble and erect formwork
    2) Prepare and place reinforcement
    3) Pour and compact or vibrate concrete
    4) Strike and remove formwork in stages as curing proceeds

WBS in Planning Tools and Visual Representations

  • Gantt charts: Used to visualize the schedule; example reference: Assignment 3.
  • Network diagrams: Used to illustrate dependencies and flow between activities (3rd year course reference).
  • WBS examples from project management software/systems, including screen captures of WBS descriptions, task names, durations, start/finish dates, and progress status (e.g., Not Started, In Progress, Completed).
  • Examples show how WBS integrates with other project controls to support planning and monitoring.

WBS Examples and Case Studies

  • Ease Project Management System example (house project): sample WBS with tasks such as Plans Development, Plan Selection, Plan Redraw with Modifications, Plumbing Plans, Electrical Plans, Obtain Permits, etc. A2 Foundation includes Clear Site, Excavation, Pour Footers, Concrete Walls, Block Walls, Pour Concrete Slabs, etc. A3 In Slab Rough Plumbing; A4 Build Shell (A4A Frame, A4B Roof House), A5 Rough Installs (Rough Plumbing, Rough Electrical, Heating), A6 Drywall (Hang/Finish), A7 Cabinets (kitchen and vanities), etc. The schedule shows phase links across a year and dates (e.g., Jul 05–Nov 05) and progress status.
  • The examples illustrate how WBS is used to structure complex projects into manageable bundles with dependencies and timeframes.
  • A separate set of screenshots and descriptions illustrates how WBS is displayed in Microsoft Project (Project2) and how tasks, durations, and predecessors are organized to form a complete project schedule.

WBS Dictionary

  • The WBS dictionary is a detailed document that provides deliverable, activity, and scheduling information for each WBS component.
  • Example entry (WBS #: 3.4.2.1, Task: Roofing sheet):
    • Est. Level of Effort: 6 days
    • Owner: Site Foreman
    • Resources Needed: Human Resource
    • Products: Roof
    • Description of Task: Provide roofing sheet for the structure
    • Input: Roof plan
    • Dependencies: Roof members
    • Risk: Falling from height, weather conditions
  • Purpose: To provide a clear, comprehensive reference for each work package, including who does it, how long, what inputs are needed, and what risks exist.

Practical Implications and Ethics

  • WBS supports scope clarity and helps prevent scope creep by defining deliverables and work packages up front.
  • It promotes accountability by assigning owner responsibilities to specific tasks.
  • Risk considerations are integrated at the task level (e.g., safety risks in roofing tasks) to inform planning and mitigation.
  • WBS supports safety planning, cost estimation, and resource planning by breaking work into discrete, observable components.
  • The structure of the WBS influences contract definitions, procurement, and project controls.

Real-World Relevance and Connections

  • WBS ties to foundational project management principles: scope management, schedule development, and cost control.
  • It aligns with traditional sequencing techniques (e.g., Critical Path Method) and modern project management tools (Gantt charts, network diagrams, Primavera P6, MS Project).
  • The examples (cup of tea, six-unit classroom block, Harbour Pointe project) illustrate how WBS scales from simple tasks to complex, multi-discipline construction programs.
  • The course references include external resources and recommended readings to deepen understanding, such as:
    • Miller, D. P. (2008). Building a project work breakdown structure: Visualizing objectives, deliverables, activities, and schedules. CRC Press.
    • Burke, R. (2013). Project management: planning and control techniques.
    • Haugan, G. T. (2003). The work breakdown structure in government contracting.
    • Baldwin, A., & Bordoli, D. (2014). Handbook for Construction Planning and Scheduling. John Wiley & Sons.
  • There are also practical online resources and software tools (e.g., WBS dictionary formats, WBS examples in project management systems, and videos) to support learning and application.

Notation and Formulas (where applicable)

  • Total project duration on a given path (critical path) can be conceptually expressed as the sum of durations along that path:
    D<em>project=∑</em>i∈CPt<em>iD<em>{project} = \sum</em>{i \in CP} t<em>i where CP denotes the activities on the critical path and ti their durations.
  • In practice, other measures such as slack, early start/finish, and late start/finish are used to manage scheduling and identify critical activities. These are derived from the network diagram and WBS relationships.

Useful Resources and References

  • Useful resources:
    • Miller, D. P. (2008). Building a project work breakdown structure: Visualizing objectives, deliverables, activities, and schedules.
    • Burke, R. (2013). Project management: planning and control techniques.
    • Haugan, G. T. (2003). The work breakdown structure in government contracting.
    • Baldwin, A., & Bordoli, D. (2014). Handbook for Construction Planning and Scheduling.
  • Online resources:
    • What is it? How do I create one? (various sources, university references)
    • AD4654C (WBS-related document): https://ablis.business.gov.au/NSW/resource/AD4654C.pdf
    • WBS video introductions and software comparisons: https://www.youtube.com/watch?v=lHMOQaKrXeg and https://www.youtube.com/watch?v=akO2Lf1fHmM
  • Software and tools references:
    • Oracle Primavera P6 and other project management dashboards for WBS and scheduling visualization

Quick Reference: Key Terms

  • Work Breakdown Structure (WBS): hierarchical decomposition of total scope of work.
  • Decomposition: process of breaking down the project scope into smaller parts.
  • Work Package: the lowest-level element in a WBS that can be scheduled and controlled.
  • WBS Dictionary: detailed information for each WBS component including resources, inputs, outputs, dependencies, risks, and owner.
  • Gantt Chart: a visual schedule showing tasks, durations, and dependencies.
  • Network Diagram: a diagram showing task dependencies and sequencing, used to derive the critical path.
  • Critical Path: the sequence of tasks that determines the minimum project duration; any delay in these tasks delays the project.
  • Assignment 3: a course task requiring Level 3 detail in the WBS.

Summary Takeaways

  • WBS is the foundational tool for translating project scope into actionable, manageable work packages.
  • It supports planning, scheduling, budgeting, risk management, and communication with stakeholders.
  • Real-world examples from construction show how WBS levels, task definitions, and dependencies translate into concrete schedules and deliverables.
  • A WBS dictionary adds depth to each item, clarifying responsibilities, inputs, outputs, risks, and dependencies.
  • Effective WBS use aligns with safety, ethics, and accountability in project management and is reinforced by recommended readings and industry resources.