Software Effort Estimation Approaches - A Review

Software estimation is the process of predicting the effort & cost required to develop software. This paper provides a general overview of software estimation models and techniques. Models can be categorized as Size-Based, Function-Based, Learning-Based and Expertise-Based. Both Size-based and Function-based models can be termed as Parametric as they use a function or formula of fixed form for software cost/effort estimation. Each has its own strengths and weaknesses. A key factor in selecting an estimation model is the accuracy of its estimates. Unfortunately, it is true that no single technique is best for all situations, and that a careful comparison of the results of several approaches is most likely to produce realistic estimates.