Page 427 - Design of Simple and Robust Process Plants

414 Chapter 10 The Efficient Design and Continuous Improvement of High-quality Process Plants

Did I select ? ? Did I really
the right pump design it right
? ? Repair the
Process pump!!!
engineer
Design engineer
Production
engineer

? ?
Okee, boss

Broken pump Did I really open
all valves ???
Operator
Maintenance man
Fig. 10.1. Broken pump,for the third time.

typical for mechanical failures. Failure rates have different distributions modes, in-
cluding normal, log-normal, Poisson, exponential, and Weibull (for details, see
Chapter 6). Failure rates are collected and put in a reliability database under its com-
ponent family with its specific component attributes. The data from one plant can
be compared with reliability databases that are open to the public domain (CCPS,
1989; Oreda, 1992) and vendor data. The failure distributions are often used for pre-
dictive maintenance programs. The evaluation and the solution to the mechanical
failures often have to be discussed with detailed engineering, and with the suppliers
of the equipment. The latter often develop equipment improvements (this is in their
best interest).
The above-mentioned grass root analysis and improvements of reliability and
availability are activities that need to be ongoing.

10.2.3
Quality of Operation

Most instrumentation systems have an event-tracking option. The event tracking
mechanism is the best way to analyze the events of process units. The objective of
the analysis is to determine what kind of actions must be taken to operate the unit,
the events being divided into:
. Alarms coming in, and its subsequent actions.
. Operational actions as step actions to move units into another operational
step.
. Control actions to overcome interaction and reject disturbances.
. Supervisory actions feed changes or product changes.