This is the core document of the IT department. This show all the service that the IT department will provide to the business.
You will have centralized information about your IT services so users will know the process of requesting services from IT. The organization will know who gets certain IT resources by default. The organization will know expectations about up time, response and resolution times for issues with the service. Will enable IT to map their IT services to Business Workflows enabling IT to provide meaningful reports to the business.