Information system outsourcing refers to the development of information systems with the help of external forces, and the construction of information systems, that is, based on the specified service level, the company entrusts all or part of the information system operations that support production and operation to a professional company by contract The act of stably managing and providing the information technology services that the enterprise needs within a certain period of time. According to the above definitions, Which of the following are not classified as information system outsourcing:. ['An information technology service company cooperates with an airline to develop an online booking system for it.', 'An information system operator continuously improves the application software system in order to provide better services to customers.', 'An information technology service provider provides a smart office platform for an enterprise and is responsible for maintaining and improving it.', 'A software company has developed a set of financial management system software for an enterprise, and improved the work efficiency of the enterprise.']