Improvement of existing process automation systems :
There are many reasons why older process control systems may need to be upgraded or improved.  A common reason is obsolesence where older control components are no longer supported by the manufacturer.

A more compelling reason to upgrade is to bring an older established industrial process to a higher level of performance.  This usually means  providing feedback on financial performance and resource efficiency in real time.  This empowers plant operating personnel to optimize operations without waiting for historical reports.