The Sourcing Grid is one of those concepts that is often talked about and, even more often, draw on dry erase boards and notebooks across the land. I was happy to see SCDigest publish a version from Dr. Ed Marien, professor emeritus at the University of Wisconsin. His version is available here:

Determining which grid your item is located, is usually very helpful to determining the proper strategy for sourcing it. Fortunately, most eSourcing tools have become quite proficient at executing sourcing projects across many of the quads. In the past, it would have been accepted to relegate eSourcing to the second quadrant for simple competitive sourcing. However, I have personally seen advanced sourcing optimization present significant value on the right half of the grid.