Our goal in this paper is to replicate the model of Gertler and Karadi (2011) and to give an elaborate overview of the way in which this model works. Instead of showing the final results, we provide a step-by-step overview of all the necessary calculations and derivations that lead to the ultimate model. Our last objective is to explain the relevance and the impact that the paper of Gertler and Karadi had. First, we describe the model with separate sections for the different agents that play a role in the model: households, financial intermediaries, intermediate goods firms, capital producing firms, retail firms, and the government (including the central bank). Secondly, we perform a Taylor approximation and import out model into Matlab. Thirdly, the model is analysed and the results are given. Fourthly, the impact of the Gertler and Karadi paper is discussed.