Zahra Barati - Computer Engineering Department, Kerman Branch, Islamic Azad University, Kerman, Iran.
Mahdi Jafari Shahbazzadeh - Electrical Engineering Department, Kerman Branch, Islamic Azad University,Kerman, Iran.
Vahid Khatibi Bardsiri - Computer Engineering Department, Bardsir Branch, Islamic Azad University, Kerman, Iran

predicting the effort of a successful project has been a major problem for software engineers the significance of which has led to extensive investigation in this area. One of the main objectives of software engineering society is the development of useful models to predict the costs of software product development. The absence of these activities before starting the project will lead to various problems. Researchers focus their attention on determining techniques with the highest effort prediction accuracy or on suggesting new combinatory techniques for providing better estimates. Despite providing various methods for the estimation of effort in software projects, compatibility and accuracy of the existing methods is not yet satisfactory. In this article, a new method has been presented in order to increase the accuracy of effort estimation. This model is based on the type-2 fuzzy logic in which the gradient descend algorithm and the neuro-fuzzy-genetic hybrid approach have been used in order to teach the type-2 fuzzy system. In order to evaluate the proposed algorithm, three databases have been used. The results of the proposed model have been compared with neuro-fuzzy and type-1 fuzzy system. This comparison reveals that the results of the proposed model have been more favorable than those of the other two models.

Fuzzy Logic, Gradient descent, Neuro-Fuzzy, software effort estimation, Type-2 fuzzy logic