Updating old process control systems to DCS, or moving out of the stone age!

Updating old/existing control systems to computer based, digital control systems (DCS) is a complex undertaking. It is anything but a “conversion” to computerized controls. More often than not, in fact, guaranteed 100% of the time, the existing process must be adequately “redefined”. Years of process updates, modifications and midnight fixes take their toll on documentation. The quantum change in man-machine interfaces (MMI) also requires considerable finesse in not just technical issues, but interpersonal and interdepartmental relationships. In addition, once the advantages and the capabilities of the new technology are appreciated, an explosion in new applications will confront the project engineer. Techniques to deal with these, and other, issues are described based on actual experience with four polyester resin, chemical process lines and associated infrastructure. Examples of what must be done differently, and why, are given along with their rationale