Abstract: There is little debate over the observation that accurate planning and estimation at an early stage of the Software Development Life Cycle (SDLC) is critical to the success of any software project. However, there is also little debate that accurate prediction of the size of a software product at an early project stage is difficult to achieve. Since software product size estimation is a primary driver in the allocation of resources to a project, there is clearly significant value in conducting the software size estimation process in such a way that it yields the most accurate results possible. To date there have been many different methods proposed to conduct software size estimation, as well as controlled and observational studies performed to assess the effectiveness of the same. In this paper I shall provide a constrained review of the literature on software size estimation, including two relatively traditional methods and two novel methods for predicting software product size at early stages in the SDLC. Specifically, I shall describe the method, scope, advantages, and disadvantages of using Function Point Analysis, Estimation by Analogy, and Use Case Analysis for software size and effort estimation.