Maryam Shahzeydi - Computer Department, Dolat Abad Branch, Islamic Azad University Dolat Abad, Isfahan, Iran
Taghi Javdani Gandomani - IEEE member Computer Department, Boroujen Branch, Islamic Azad University Boroujen, Iran

Software cost estimation has been always a serious concern among the software experts. Although, a few estimation models and techniques have been provided in disciplined based software methodologies, Agile methodologies most often use Planning Poker technique for software cost estimation. This technique promotes coming to consensus when suggesting size of each user requirement (known as User Story). However, most often software experts ask whether is necessary to reach to a consensus or not. They also, offer considering the average of the suggested sizes (cost) of User Stories instead of focusing on consensus on them. The main aim of this paper is to present the results of a case study research which has been carried out to compare the accuracy of both disciplines. The results shows less accuracy when team get an average of the User Stories compared to coming to consensus about the size of User Stories.

Agile software development, Agile methods, Agile cost estimation, Planning Poker