Page 325 - Improving Machinery Reliability

294 Improving Machinery Reliability

Maintenance personnel visit the pump monthly for routine PM inspection, lube oil
additionkhange out, and emissions tests. Maintenance cost is US$SO/hour for labor,
incidental materials, and expense with 1 hour on the average charged per visit. No
failure times are incurred during this activity.

Annual maintenance PM costs are (12 visits * 1 hour/visit) * US$SO/hour =
US$600
Operations visits the pump once per week for routine PM inspection and vibration
logging. Operations cost is US$35/hour for labor and expense, with 0.2 hours
charged for each visit.

Annual operations PM costs are (52 visits * 0.2 houdvisit) * US$35/hour =
US$364
The Reliability Group receives vibration data from operations by e-mail and scans
the data weekly for abnormalities. Surveillance cost is US$SO/hour for labor and
expense, and on the average, 0.2 hours is charged for each weekly visit.

Annual vibrations PM costs are (52 visits * 0.2 houdvisit) * US$SO/hour =
US$520
Maintenance and operations conduct a joint tailgate training session on good
maintenance and operation practices for this pump once per year. Three people
from maintenance attend at US$SO/hour-person and three people from operations
attend at US$35/hour-person. The training session consumes and elapsed time of
0.5 hours.
Annual training costs are (0.5 hour * (3 people * US$50 + 3 people * US$35)) =
US$128
Disposal costs will occur as a lump sum at the end of the ten-year remaining life
are expected to be US$500 for permits and legal costs associated with disposition,
US$500 for wrecking/disposal costs, US$l,OOO for remediation costs, US$O for
write-off/recovery costs, and US$ 1,000 estimated green/clean costs associated with
disposal of the asset. These costs will occur in the final year. Table 5-1 1 shows non-
annualized acquisition and sustaining costs for the existing solo ANSI pump, while
Table 5-12 shows the annualized recurring costs.
A quick cost review of the single ANSI pump shows lost gross margin from out-
ages is the biggest annual cost problem as shown in Table 5-12 for a sustaining cost
of US$54,827/year. The ANSI pump will consume 16.7 corrective and 35.8 preven-
tive man-hours each year.
Use of MTBFs and expected failures are based on the exponential distribution
that is an acceptable first cut for costs, but this technique is not an accurate predic-
tor of failures for wear-out phenomena expected for many of these components. An
improved accuracy method will be described later using Weibull distributions for
failures.