What is your experience with "first run capability" as an ongoing process metric?

"First run capability" is a relatively simple concept with a direct method of calculation. The concept is reflected in the statement below:

"If you loaded the process inputs with enough raw material and parts to produce, say, 10,000 parts, how many would be produced if there were no repairs or other corrections to the process?"

If 9,000 parts were produced, your first run capability would be 90%. The objective then is to track first run capability and use the data to improve the process.

To further illustrate the concept suppose there was a 3 step process. Each step in the process passed 90% of the work presented to it. Then your first run capability would be 72%. (0.9 x 0.9 x 0.9). The 28% that is lost represents waste and/or added cost to repair. There are added quality concerns about the 28% the deviate from the straight-through process.

Comments and/or experiences with this metric?