Applications have a life cycle that after a while can prove more difficult to maintain than redo. Remember when web pages were static and developed to a specific size? Accessing them today with a phone or a tablet forces users to scroll all over the page to view the full content. Modernization is when a legacy system gets redone and put into a more modern application space. Understanding the strengths and weaknesses of each modernization technique is paramount to select the correct solution and the overall success of a modernization e↵ort. This thesis describes what to take into consideration when planning a modernization. Why should organizations consider modernization? What are the costs? What can be done to achieve better and efficient modernization for the next generation and how do they decide the correct time to modernize? To answer these questions a practical study was done using a legacy system written in Java and modernizing it to the ASP .NET framework. An interview with the client ordering the modernization was conducted to understand the reasoning an organization has regarding modernization. Results showed that modernizing can and will often be a great way to expand business capabilities but the major limitation is the finance. Here lies a problem due to the challenging nature of knowing the return of investment regarding modernization and calculating risk vs. reward scenarios. However, the planning stage is of major importance and it can reduce the modernization cost significantly.