The interrelationship between a plant design and its closed-loop performance has led to an awareness that dynamic operability issues need to be considered at the plant design stage. This in turn motivates the need for systematic procedures whereby the operability of competing plant designs may be assessed. Particularly useful would be a measure of inherent plant operability, independent of controller type or tuning. A procedure for computing a measure of this type is presented in this paper. It utilizes e-parametrization as a representation of feedback controllers which permits operability assessment to be posed as a convex optimization problem; the solution of which represents the best achievable performance for any linear feedback controller. The formulation of the method is presented and its application demonstrated through example problems.