The services of information department include software development acquisition, development and information service. The information system CMMI® for Acquisition (CMMI-ACQ) is introduced to understand the international standard of information system's outsourced acquisition operation flow, which can effectively enhance the quality and effectiveness of planning and the implementation of information outsourced operation, establish fair and reasonable partnership with suppliers, and realize the win-win result for both supplier and buyer. This research analyzed the process of CMMI-ACQ import by the case company in order to improve the outsourced software development, understand the practice, and use it as the basis for popularizing to the delivery system CMMI® for Development (hereinafter referred to as CMMI-DEV and CMMI® for Services (hereinafter referred to as CMMI-SVC). The case company adopts the implementation procedures of IDEALSM (initial, diagnosis, establishing, acting and learning) to establish improvement plan practice, formulate the conforming standard for acquirer and supplier as reference for the company or the same trade when importing CMMI® project. Research findings showed that, standard practice can ensure the project quality of different units or teams even if the implementation method has been changed, improve the possible deficiency, and enable the project to be completed as scheduled. The case company depends on the CMMI-ACQ import experience to establish the optimal development and monitoring management collaboration mode with supplier, thus comprehensively popularizing to all software development operations of this company.