Estimation of the parameters of software reliability
models using the traditional techniques like the maximum
likelihood method and the least squares Method pose some
difficulties since the models are generally in non-linear
relationships, [15]. The derivation and calculation of the
MLEs usually require specialized software and more
powerful computers for solving the non-linear equations.
Some researchers, for instance, [16] argue that the difficulty
experienced in the computations of MLE is less of a
problem as time goes by as more statistical packages are
being developed to contain and solve the complex
maximum likelihood (ML) equations. However, these
statistical packages require more complex algorithms and
programming languages for them to work. MLEs are also
heavily biased when there is small data on failure times,
[17]. In this paper, we have presented a simpler and more
efficient parameter estimation method for the Goel –
Okumoto software reliability model. This stems from the
fact that the logarithm of the intensity function of the model
is a linear function of the software failure times and the
parameters can thus be estimated using the traditional least
squares regression method. The estimates thus obtained are
better than MLE which is the widely used method in
estimating the parameters of the model. It is also worth
noting that when the parameters of the model are estimated
using simple linear regression method, the results obtained
are still better than MLE method