Page 402 - Design of Simple and Robust Process Plants

9.6 Project Methodology for Operation Optimization 389

Business

O.O

Operation MBC

BC

AI/DI’s AO/DO’s
Process

Fig. 9.15. Communication plan between BC, MBC, OO,
Operation and Business.

The above illustrates the need to define clearly the premises for BC, MBC and OO,
and who is doing what. The premises for the control design are the following:

. A lower level of control should be able to function independently of an outage
of a higher level control.
. Basic control should be designed simple and robust with a high disturbance
rejection capability and require a minimum of operator attention during out-
age of a higher control level (MBC and OO).
. The hierarchy of the control configuration should be clearly defined and, in
an actualized format, presented to operation.
. Operational input should be implemented through one workstation to
approach BC/MBC/OO.
. Higher control layers always send their outputs to the basic control layer, and
will not directly activate a AO or DO.

9.6.5
Build Executive and Implement Data Analysis, for Steady-State Detection and
Performance Meter: Step 4
The executive operates the optimization cycle as discussed in Section 9.5.2. The soft-
ware framework for this functionality is available commercially. During develop-
ment of the OO, the executive will be implemented and the individual steps tested
and evaluated step-wise.
The implementation will start with the performance meter, at which point the
data analysis based on improved control design is not yet available. The performance