Software Cost Estimation

Software cost estimation is the process of predicting the effort required to develop a software system. Many estimation models have been proposed over the last 30 years. This paper provides a general overview of software cost estimation methods including the recent advances in the field. As a number of these models rely on a software size estimate as input, we first provide an overview of common size metrics. We then highlight the cost estimation models that have been proposed and used successfully. Models may be classified into 2 major categories: algorithmic and non-algorithmic. Each has its own strengths and weaknesses. A key factor in selecting a cost estimation model is the accuracy of its estimates. Unfortunately, despite the large body of experience with estimation models, the accuracy of these models is not satisfactory. The paper includes comment on the performance of the estimation models and description of several newer approaches to cost estimation.