The Six Sigma Handbook, Revised and Expanded, 2nd Edition

15.3. WORK BREAKDOWN STRUCTURES

Ruskin and Estes (1995) define work breakdown structures (WBS) as a process for defining the final and intermediate products of a project and their relationships. Defining project tasks is typically complex and accomplished by a series of decompositions followed by a series of aggregations. For example, a software project to develop an SPC software application would disaggregate the customer requirements into very specific analytic requirements (e.g., the customer's requirement that the product create X-bar charts would be decomposed into analytic requirements such as subroutines for computing subgroup means and ranges, plotting data points, drawing lines, etc.). Aggregation would involve linking the various modules ...