Page 411 - Improving Machinery Reliability

Maintenance for Continued Reliability 375

of maintenance on the basis of maintenance costs alone; but now, must engage in an
active dialogue with their colleagues on the production side to determine the “trade-
off” between slightly increased maintenance cost and considerably reduced profit
loss through plant outage.
The primary function of plant maintenance management is to keep a plant operat-
ing at maximum efficiency for a desired period of time. Here, we define “plant” as
meaning boilers, furnaces, compressors, turbines, pumps, piping, and instrumenta-
tion, as well as buildings and grounds. While each of these components is important
in its own way, items such as piping, valves, heat exchangers, and strainers are fairly
easy to maintain. Nearly all journeymen craftsmen, whether staff or subcontract, can
handle most normal maintenance. When it comes to more highly sophisticated
machinery, however-machinery which by economic necessity has no standby, and
which is in many instances the very heart of a plant-maintenance supervision must
continually evaluate practical alternatives to ensure minimum downtime.
It seems that plant management, when considering the maintenance alternatives
for key machinery in a single-stream plant, has three major options open to them.
Tlhese three alternatives remain valid regardless of the size of the facility, in that
units tend to be operated by sections, or “plants within plants.”
The first and most obvious option is to try and handle the entire plant maintenance
operation with captive, or “in-house,” manpower capability. The second option is to
employ full contract maintenance, and the third option is to employ the “peak shav-
ing” maintenance concept.
Let’s look a little more closely at each of the three, and evaluate the factors that
might be considered when selecting the best alternative for your plant.

Captive, or In-House, Maintenance
Advantages

Under most normal circumstances, you’re dealing with craftsmen who are loyal
employees, who respect the objectives of your maintenance program, who have a
vested interest in the continued success of your company, and who can be trusted
with any proprietary features of your process.
They are aware of your company rules and procedures and recognize the threat of
termination of their employment in cases of proven incompetence.
Captive employees must live with the results of their work-they can’t just walk
away and expect someone else to “pick-up the pieces.”
Should an emergency arise, captive personnel are right there, ready to go to work.

Disadvantages

*What size crew is required to maintain your plant? While a full-time base-load
staff is essential, manning in excess of the base-load workforce is demonstrably
inefficient.
This method of maintenance tends to encourage and justify overstaffing.