The characteristic locus method, in addition to its role in the assessment of system stability, is also an effective approach for evaluating tracking accuracy, interaction and dynamic/static loop performance. However, with regard to the evaluation of the latter three, there exists a degree of ambiguity and personal judgement, in addition to a requirement for aprioriassumptions about proper problem conditioning. This paper stipulates quantitative bounds/measures of accuracy, interaction and loop assessment that identify the pertinent open-loop system factors affecting the particular performance aspect, and thus provide unambiguous measures to aid system design. Additionally, eigenvector scaling is introduced in order to tighten the bounds.