Plant fault diagnosis system

A plant fault diagnosing system, comprising:

• instrumentation means for providing process data representing physical operational characteristics of a plant process, diagnosing means for diagnosing faults in the plant in accordance with a relationship between said process data and at least one of predetermined information regarding fault diagnosis and a changeable reference value based on said process data, said diagnosing means including means for generating a diagnosing pattern which symbolically represents said process data;
• means for displaying the diagnosis given by said diagnosing means;
• a memory for storing said predetermined information and also for outputting said predetermined information to said diagnosing means, said predetermined information including importance factors which define the relative importance of the diagnosed faults;
• said diagnosing means including means for estimating a first amount of time which will elapse between the diagnosis and the actual occurrence of each fault based upon the physical properties of the plant process and said process data, means for estimating a second amount of time required to avoid the occurrence of the fault, means for subtracting said second amount of time from said first amount of time to thereby calculate an estimated floating time available before a fault avoidance operation should begin, and means for calculating an urgency factor based on said estimated floating time and said importance factor;
• and
• said displaying means including means for ranking and displaying the faults in sequential order based upon respective magnitudes of said urgency factor and said floating time.