Hubbard writes about performance measurement in chapter 11. He notes that management typically knows what are the relevant performance metrics. However it has trouble prioritizing between them. Hubbard's proposal is to let the managament create utility charts of the required trade-offs. For instance on curve for programmer could have on-time completion rate in one axis and error-free rate in the other (page 214). Thus the management is required to document how much one must increase to compensate for drop in the other. The end product of the charts should be a single index for measuring employee performance.