A design of a sales system for professional services requires a comprehensive understanding of the dynamics of sale cycles and how key knowledge for completing sales is managed. This research describes a design model of a business development (sales) system for professional service firms based on the Saudi Arabian commercial market, which takes into account the new advances in technology while preserving unique or cultural practices that are an important part of the Saudi Arabian commercial market. The design model has combined a number of key technologies, such as cloud computing and mobility, as an integral part of the proposed system. An adaptive development process has also been used in implementing the proposed design model.