Decision models can be a useful tool to extrapolate information from randomized controlled trials and investigate colorectal cancer (CRC) screening in specific problem conditions. The aim of this thesis is to first describe the steps that are required to standardize the structure of a microsimulation model (as MISCAN-Colon) and make it as the core of an online user-friendly model application. Briefly, these steps include: i) assessing effectiveness of CRC screening in different screening settings; ii) validating the model structure and its assumptions; and iii) building an online user-friendly platform that allow users to easily upload country-specific data, adjust a model, and simulate future outcomes of CRC screening in their countries. Subsequently, this thesis aims to demonstrate how models can be used to help policymakers in their decisions about CRC screening regarding populations at different risk of CRC.