Abstract
This paper provides a a framework to evaluate the transition to a OSS software solution in terms of returns and losses in the context of Public Administrations. The ultimate goal of the framework is to identify costs that are not easy to trace or that are not usually collected like user acceptance. The framework has been conducted using a Total Cost of Ownership approach, which is the most frequently used model to conduct cost comparisons between two or more IT systems. The study further implements the Goal Question Metric paradigm to identify the cost metrics. The framework relies various methods to collect the data, including questionnaires with end-users, qualitative interviews with IT-managers and company balance sheets. An example of framework's use is provided.