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As we stated last month, when we "begin to gain the Operator's perspective to leverage decades of their experience to provide improvement, we typically find a fellow Cognitive Conqueror." We also identified the problem of not incorporating the knowledge of the Cognitive Conquerer in updated control algorithms equates to throwing significant wads of cash in the garbage.
Our job is to find that hidden treasure and turn waste into profit. This begs two "how" questions to be asked: How do we know what needs to change? And, how do we change it? The answer to the first question often rests heavily on the seasoned Operator. The answer to the second question frequently requires the seasoned knowledge of both the Operator and the Systems Integrator.
How do we know what needs to change?
Before delving into what is wrong, we must begin by understanding the process. Having an intelligent conversation with a fellow Cognitive Conquerer requires some getting up to speed. Reviewing P&IDs, existing programs/HMIs, network structure, and other documents is not enough. We have to walk the process in preparation, like we have done hundreds of times before for hundreds of different processes. Once we have done the pre-work, we begin data mining. A sample of our more productive data mining areas to identify this treasured knowledge include:
- Ask the Operators to identify the process disturbances that:
- wreak the most havoc;
- require the most manual control; or
- require the most forewarning to keep the process running smoothly.
- Note significant changes in operating modes and setpoints and ask why.
- Ask about reliability issues (e.g. instruments) and how to keep things running during failures.
- Identify when there are significant deviations in the time to complete certain actions or phases.
- Review the SOP, batch sheet, etc., and ask where process time is wasted.
- Above all, listen.
How do we change it?
The answers are numerous and often the point of these articles. The challenge is to take the right tools from the process control tool bag and address the problems to improve performance. One of the more common tools used to eliminate the negative effects of process disturbances identified in question #1 above is a feed forward control. Other times, different tools are required. What is important is the size of the tool bag and one's ability to use the tools effectively.
Traditional control approaches, such as the ever popular PID for example, have an inherent limitation because they do not take action until the error is evident and tight control is lost. When the Operator identifies the process disturbance that requires the most foreknowledge, he has identified a need for feed forward control and the basis for its computation to make the right adjustments. Furthermore, the actions he takes to keep things running smoothly identify how control is achieved. The energy balance calculations or other details of the control algorithm can then be achieved with the proper focus. As we said last month, Avid Solutions can help you leverage the experience of your Cognitive Conquerors in combination with our own to reach and exceed your desired results. |
