There are many formal definitions of IT Service Management (ITSM), but to put it simply, ITSM aligns operational IT support with organizational goals. IT should add value to organizations by enabling and improving critical processes and workflows.
Strategic planning and management of IT services comes into the picture in several ways.
First, organizations may decide to make minor or major changes to their process for increased efficiency or to steer a course for long-term strategic goals. IT would support these changes by being involved in the initial discussions and helping plan the transition from the current state of operations to the desired state of operations.
Second, an IT organization may decide that it could deliver services more efficiently with different processes or technology. Aside from deciding to implement its own change, external sources of change would also drive the need to plan strategically.
The diagram below illustrates the path from organization demand to IT service value: