Information Technology Reference
In-Depth Information
UAL
1968
Bromsurg
1979
U.S. Navy
1982
II
8
23
Total (%)
Time
Failure rates similar to the bathtub curve in only
small % of cases
89
92
77
Total (%)
Time
Majority of failures are random, remaining
fairly constant over time
Figure 1.2
Nowlan and Heap's findings.
fresh in production, the failure rates are high. “Burn-in” is a concept used
in the electrical and mechanical industries, wherein machines run for short
periods of time after assembly so that the obvious defects can be captured
before being shipped to a customer. In the software industry, alpha and
beta programs are the burn-in. In fact, most customers are wary of
accepting the first commercial release (v 1.0) of a software product. The
longer a system is used, the higher the probability that more problems
have been unearthed and removed.