Many plants tend to focus on statistical averages of performance, such as average cost, reject rate, or percent uptime. These are excellent measures of process results, but in order to make improvements, we need to focus on real time measures of performance. These measured should meet the following three criteria:
• Meaningful
• Measurable
• Actionable
When measure is actionable, it helps to lead you directly to a corrective action. The key to making process improvements is to measure the right things, and then to respond with the right corrective actions.
Some of the most common real-time measures that meet these criteria are presented along with a discussion on how these measures can be made available via a PSS (performance supervision system). A PSS monitors real time data, calculate performance metrics.
With the advent DCS (distributed Control System) and open communications technologies such as (OPC) OLE for Process control, now process plant has access to wealth of real time information. A real time PSS can crunch through all the raw data and develop meaningful real time performance measures.
The process plant has already gathering real time data from instrument throughout the plant with a PLC control system or DCS. Control systems have been doing for years. More currently, control system vendors have been opened up their proprietary systems. OPC is a series standards communications that provide open connectivity in industrial automation systems.
Once the data is available via OPC, it can be shared with:
• Other control system
• Supervisory control
• Real time data historians
• Performance supervision systems
Performance supervision systems will perform many of these calculations automatically, based on the available real time data. The real time data from plant instrumentation can be transferred via OPC or historians into a PSS. Web based plant dashboards can make the data accessible to users throughout the plant or even the corporation.