Journal of Information Organization Cheng WANG *, Zhixiao LIN, Fangsheng GUOTANG, Lixiao ZHENG, Zhigang ZHU 5 3 2015 http://www.dline.info/jio/fulltext/v5n3/v5n3_3.pdf In order to build a practical mini OA system for small and medium enterprise, key business, overall requirement, functional requirements and non-functional requirements of Yardi Kooboo (Xiamen) Technology Co.Ltd. are analyzed after understanding the company’s specific workflow and management processes. Following software engineering, the entire progress of building a WPF-based OA system includes functional module design, database design, achievement of three-tier architecture, achievement of mail cache and so on. Deployment of this new OA system improves the level of information management and obtains good application effect. The development process provides good reference value for the development and research of similar systems.