Rockwell Automation Arena Packaging Users Guide - Manual (Page 93)

A • E QUIPMENT R ELIABILITY AND L OSS
87
•
•
•
• •
A •
R
eli
abi
lity
and Lo
ss
Using the above data, the reliability of the filler machine for one month is calculated as
follows:
t = 1 month
λ = 10 failures/6 months = 1.667 failures/month
R = e-1.667*1 = .189
Similarly, the probability that the filler machine can run for three months without failing
is:
R = e-1.667*3 = .007
Arena Packaging’s second option for specifying equipment downtimes implements failures
using this probabilistic definition. When selecting this option, specify the time span (t) in
days, the reliability for the time span (R), and the time to repair a failure when it occurs
(i.e., Time to Repair). Here, the Time to Repair operand can be specified as a random
distribution (e.g., TRIA (15,22,25)).
For example, suppose you needed to model the bottling line at Company XYZ and wanted
to use their failure data for the filler machine. You could enter the Reliability dialog of the
filler and specify the Time Span, Reliability, and Time to Repair as 30, .189, and 22,
respectively.