Overview of problem definition
The first step in configuring your blueprint is defining the problem. Due to the distinctive nature of problems, illustration by example is the approach we will use within this exercise.
In this section we go through an example of the use of Architect as a process deviation diagnostic system (PDDS).
Process deviation diagnostic system
-
As the name suggests, a process deviation diagnostic system monitors a system variable and determines the causes for deviations in this variable from the set point or set point boundaries.
-
This is achieved by analyzing the model that predicts the variable that must be controlled, since the model contains valuable information regarding the nature of the relationships between the various variables in the system at any one time.
-
It is also able to suggest which of the controlled variables should be changed to bring the monitored variable closer to its set point or set point boundaries.
Process deviation diagnostic systems
Problem example
The example that we will use is that of a centrifugal pump. Several measurements are available and include the; inlet (Pi) and outlet pressures (Po), the fluid flow rate (F) and current drawn by the pump (I). A diagram of the pump and available measurements is given below:
diagram of the problem example showing the available measurements
Terminology
-
Set point - a predetermined position or value for a particular process variable to be implemented by an automatic controller
Related topics: