Quality index framework for plant-wide performance evaluation

The complexity of industrial production plants results in difficulties in obtaining an overall view of plant performance and in finding the weak links that deteriorate performance and product quality. While control loop performance assessment is a popular subject, few authors address the problem of combining low-level performance indices into subsystem and plant level indices. This paper presents a performance assessment framework enabling the creation of different views to plant performance. In the proposed method, low-level performance indices are scaled to the same interval so that their interpretation, comparison, and combination are more straightforward. Different methods for combining low-level indices to create subsystem and plant level performance measures are studied. Implementation in a large-scale industrial process is described.