Work breakdown structures (WBS)

Work breakdown structures (WBS) are special codes that enable you to attach additional information to each item (say, a code to store a bid item number, estimator, or department). You can use these codes to organize the estimate in other sequences and report on items in various ways.

Here are some links that can help you get started:

Defining work breakdown structures (SQL) 

Adding new work breakdown structure values (SQL

Changing an existing work breakdown structure (SQL)

Changing existing work breakdown structure values (SQL)