K.
P. Singh
Department
of Biostatistics
School
of Public Health
University
of North Texas Health Science Center
Fort
Worth, TX 76107
U.S.A.
S.
C. Sharma
Department
of Statistics
J.V.
College
Baraut,
Uttar Pradesh 250611
India
S.
J. Bae
Department
of Biostatistics
School
of Public Health
University
of North Texas Health Science Center
Fort
Worth, TX 76107
U.S.A.
Study
of combined effects of imperfect repair/maintenance/debugging and failure on
the dependability of a software system is in the core of the present paper.
Faults/bugs may cause the degradation or failures to the software. Failures,
categorized as minor, marginal and critical need the maintenance personnel for
software repair. Measures of the dependability such as mean time to system
failure (MTSF),
availability, mean sojourn time, and busy periods of the maintenance personnel
due to different failures are derived using the regenerative stochastic
process. The expected profit/cost aspect is also taken into consideration.
Numerical examples are given for illustrating the graphical behavior of Dependability
measures, MTSF and availability.
Keywords
and phrases: Auto
recovery, error handling mechanism, degradation, perfect/imperfect repair/debugging,
mean sojourn time, mean time to system failure, cost, regenerative stochastic process.