The precise estimation of the time effort of the project is one of the key limits of its success. One of the ways how to achieve a correct valuation of the project is developing of a detailed analysis, which output is a structured solution that uses use cases. This paper focuses on developing a methodology for estimating working time effort of the project for one particular company. An important part of the methodology is to build up and maintain comparative database of valued use cases and time progress of realized projects. The aim of the methodology is to deliver data for evaluating a new project.