Guideline: Develop a Work Breakdown Structure Based on the Product Architecture
This guideline describes how to establish a top-level product-oriented work breakdown structure.
Relationships
Related Elements
Main Description

A work breakdown structure (WBS) divides the project into a related set of manageable components. It provides a structure for identifying and organizing the logical units of work into work packages that will be managed. The WBS is used as a tool and reference for assigning effort and for scheduling. It is used as the primary framework for planning, organizing, and controlling the work performed on the project.

Developing your work breakdown structure based on the product architecture allows you to organize and plan project work around the components of the product to be developed so that relationships between WBS elements are easily understood. This organizational approach supports detailed resource planning, ensuring that assignments and the responsibility for those assignments go to the appropriate resources. It also creates a structure for accurately estimating cost and for allocating budget. Component-based decomposition into work packages also provides a strong framework for risk and impact analysis.

Define the work breakdown structure components

Decompose the work breakdown structure from the system (top) level into lower-level components. Each WBS component must be described in verifiable terms so that successful completion and delivery are easily measured. Work products such as requirements specifications, architecture overview diagrams, and component models are useful inputs to this effort.

The general structure should follow this pattern:

  • Top Level - System
    • Subsystems
      • Components
        • lower levels of decomposition as needed.

A WBS can be decomposed to any level of interest depending upon the level of risk or cost.

Assign responsibility

Each component must be assigned to the team or resource who will take responsibility for completing the work.

The resulting structure should define the product to be developed and relate the elements of work that must be performed to each other and to the end product.

Considerations for Agile teams

Agile teams typically do not produce a formal work breakdown structure. To achieve the benefits of a product architecture-based planning tool, the Work Items List (WIL) can be organized by components.  Stories or high level components are defined with child-level work items capturing the tasks required to complete each story or component.