Software engineering

Software Reliability Model

According to ANSI , Software Reliability is defined as : The probability of failure-free software operation for a specified period of time in a specified environment . Software reliability also determines the quality of the software . Software failures must be minimized to increase the reliability of the software . Software failure occurs as a result of error and mistake in writing code , improper testing and unexpected usage of the software . It is simply the measure of probability of failure occurring in the software

Software reliability models are used to characterize why and

how the software fails and to quantify the reliability accordingly . Several software reliability models exists and each of them are used in different situations . Some of the parameters used to calculate the software reliability are average intensity and mean time to failure . Musa basic , musa-okumuta schneidwind , littlewood - verrall , goal-okumuta are some of the important software reliability models

Musa model is the basic software reliability testing model . The various assumptions in this model are as follows

Faults are independent in nature

Faults are distributed with constant rate of encounter

Inputs are randomly selected from the input domain

Fault causing failures are corrected immediately after the occurrence is encountered

All failures are observed and implied by the definition

Failure intensity can be found using the average number of failure intensity over the time

The software reliability is estimated from the measurement of failure intensity . The failure intensity can calculated as follows

Failure intensity Initial Failure Intensity...