Jelinski & Moranda Model

Introduction

We will learn about Jelinski & Moranda Model in this blog. 

Jelinski and Moranda Model

One of the first software reliability models is the Jelinski-Moranda (J-M) model. This basic concept is the basis for many existing software reliability models.

Characteristics

• It's a model of the Binomial type.
• It is undoubtedly one of the first and most well-known black-box models.
• The J-M model generally makes overly optimistic reliability predictions.
• JM Model performs a perfect debugging phase, in which the observed defect is removed using a certainty simple model.
• In the JM model, the constant software failure rate at the i^th interval is given by:
                      λ(t_i) = ϕ [N-(i-1)]
  where, 
  i = [1, N]
  ϕ = a proportionality constant denoting the rate of failure provided by each fault
  t_i = time interval between i-1^th and i^th failure

Other characteristics of the JM model are:

Assumptions

Following are the assumptions of the JM Model:

• The exact amount of initial software defects is unknown, but they are constant and fixed.
• Each software error is unique and has an equal chance of causing a test failure.
• The time intervals between failures are random variables with an exponential distribution.
• Over a wide range of fault occurrences, the software failure rate remains constant.
• The number of faults that exist in the software determines the failure rate.
• An identified error is promptly corrected, and no additional errors are introduced during the removal of this detected error.
• Whenever a failure occurs, the corresponding defect is certainly removed.
   

Also see,  V Model in Software Engineering