Cost-benefit Analysis of Instrument Maintenance Policies and Data Reconciliation Related to Plant Data Accuracy

Accuracy of process data is defined as the sum of the bias of the measurement plus its precision. In this paper, we overview the effect of using data reconciliation in the accuracy of data and we show the benefits of installing data reconciliation thus providing a tool to determine if a data reconciliation package is financially justified. Because new sensors improve the power of data reconciliation and gross error detection, we also discuss the effect of adding new sensors on accuracy, as well as on plant economics. Finally, instrument maintenance reduces the number of undetected gross errors, and therefore improves accuracy and plant economics. The tool we present helps determining how much a good (fast) corrective maintenance helps plant economics. In sum our methodology can help resolve the ever present dilemma of how much economic investment and operational resources should be put to strike the right balance with financial gains.