K. Havre and S. Skogestad, ``Input/output selection and partial control,'' IFAC World Congress, San Francisco, July 1996, Volume M, 181-186.

Abstract.
This paper considers the process of control structure design, and in particular it addresses the issue of selecting measurements and manipulations for partial control. Partial control at a given level involves controlling a subset of the outputs with an associated control objective. The relative gain array (RGA) and singular value decomposition (SVD) are useful measures for selecting inputs and outputs.