The Data Warehouse Toolkit: The Definitive Guide to Dimensional Modeling, 3rd Edition

Chapter 5

Procurement

We explore procurement processes in this chapter. This subject area has obvious cross-industry appeal because it is applicable to any organization that acquires products or services for either use or resale.

In addition to developing several purchasing models, this chapter provides in-depth coverage of the techniques for handling dimension table attribute value changes. Although descriptive attributes in dimension tables are relatively static, they are subject to change over time. Product lines are restructured, causing product hierarchies to change. Customers move, causing their geographic information to change. We'll describe several approaches to deal with these inevitable dimension table changes. Followers of the Kimball methods will recognize the type 1, 2, and 3 techniques. Continuing in this tradition, we've expanded the slowly changing dimension technique line-up with types 0, 4, 5, 6, and 7.

Chapter 5 discusses the following concepts:

• Bus matrix snippet for procurement processes
• Blended versus separate transaction schemas
• Slowly changing dimension technique types 0 through 7, covering both basic and advanced hybrid scenarios

Procurement Case Study

Thus far we have studied downstream sales and inventory processes in the retailer's value chain. We explained the importance of mapping out the enterprise data warehouse bus architecture where conformed dimensions are used across process-centric fact tables. In this chapter we'll extend these concepts ...