This thesis is to study how enterprises develop their new businesses with a special focus on the computer software business. It starts from the industry maturity model and see how important it is to generate innovations in the mature stage. Then, it introduces new software service models in which a software vendor plays an important role in creating a total solution. This research also illustrates how different strategic intents and competitive advantages will impact to the service design and management. We will mainly use the case study of Trend Micro Inc. to show how they innovate since the company started, and focus on the analysis on how the new service, Trend Micro Expert Service, is developed and grew, the challenges new service business development face including strategy, management and organization. It will address especially on the interactions between core business and new businesses. Through this study, we can understand how a software product company can best develop their new service business in a systematic way.