Project portfolio management (PPM) software tools remain a popular method for automating the process of gathering, evaluating, managing, tracking, and reporting on IT's project investments, and Forrester continues to see growing interest in PPM tools delivered via the software-as-a-service (SaaS) model. With the rising popularity of SaaS PPM tools, Forrester clients are increasingly curious about how much they will pay for these options. Based on information provided to Forrester from vendors during the recent Forrester Wave™ evaluation of PPM tools and several follow-up interactions, Forrester has created a simple tool for estimating the cost of a SaaS PPM implementation.