This paper introduces a new four-parameter lifetime model called the
odd log-logistic Dagum distribution. The new model has the advantage of
being capable of modeling various shapes of aging and failure criteria. We
derive some structural properties of the model odd log-logistic Dagum such as
order statistics and incomplete moments. The maximum likelihood method
is used to estimate the model parameters. Simulation results to assess the
performance of the maximum likelihood estimation are discussed. We prove
empirically the importance and exibility of the new model in modeling real
data.