The aim of this thesis is to present a proposition of a component-based design which will be used to solve a problem for companies who works with several business systems’ API-components. The solution that is achieved is a component-base inteface that can be customized, maintained and expanded by the user. Our solution describes a design which let the developers at these companies to work against a component-based interface that, programatically, looks and works the same regardless of which business system API they work against. We will use a mixed methodology, that is, we will use both qualitative and quantitative methods to reach our result and conclusions. The choice to use a mixed methodology is based on that it generates more groundwork for us to reach a better result. We will present the background theory for the reader to better understand and interpret our result. We will present our result in three ways: a design, an evaluation of the design and a implementation. Each based on one of the methods we used to reach it. The thesis will be concluded with a discussion, method evaluation and a summary, where we will discuss the work with the thesis and what the result tells us. There will also be a short summary of our choice of methods have worked for us. At last we will reflect on future work, and what might be the next step to take to strengthen and improve our result.