Abstract:During the period of development of the products, the reliability is always growing for the improvement of the designation, technology, materials, etc. Considering the reliability growth characteristics of the product during development phase, based on the nature of the Duane learning curve, the exponential reliability growth models was studied, and the parameters of the maximum likelihood estimator and reliability assessment method were given. The case study results show that the model is simple, actual project for small sample reliability growth assessment.