The goal of this article is to contribute to the decision of how to analyse and evaluate the economic impact when deploying large IT solutions. For that purpose, we present a framework, which can be applied by carrying out the following steps: At first, important preconditions and assumptions concerning the IT solution have to be collected. Then, key factors, derived from the results of the previous step, can be identified. Finally, these factors have to be evaluated and, if possible, quantified and measured. Consequently, these steps have to be embedded in the development process of the IT solution. We describe a procedure model, based on the stages plan, do, check, act, which can be used to carry out a structured analysis taking into account the whole life cycle of the deployed IT solution, including an ex-post analysis. As foundation of the framework, we provide a classification of key factors of IT benefits and risks based on literature and case study review.