Q. Explain Logarithmic Poisson Execution Time Model?

This model is as well developed by Musa et Al (MUSA79). The breakdown intensity function is different here as compared to Bias model. In this case breakdown intensity function (decrement per failure) decreases exponentially whereas it is constant for basic model.

This breakdown intensity function is given as:

L (μ) = l₀exp (-qμ)

Where q is describe as failure intensity decay parameter.

The q represents the comparative change of allure intensity per failure experienced. The Failure intensity of the logarithmic Poisson execution time model drops more rapidly initially than that of the basic model and later it drops more slowly. The appearance for failure intensity is given as

l(i) = l₀/(l₀qi+1)

The associations for the additional number of failures and additional execution time in this model are:

Therefore at larger values of execution time the logarithmic Poisson model will have larger values of failure intensity than the basic model.