Gap Analysis - comparison of the current situation to the desired state.
In a management improvement framework the important processes are identified. Then develop the desired state (from customers and internal customers) and document the current Voice of the Process. The gap between these two should be documented.
Then a plan to move from the current state to the desired state should be developed. The proper detail in the plan depends on the scope. For very simple gaps, where the knowledge to move from the current state to the desired state is well understood, a simple plan to do "x, Y, Z" may suffice.
Most often however, the problem is more complex and the plan to move to the desired state will involve project action teams, testing potential solutions on a small scale, studying various options, etc.