A method comprising a self-organising network function control unit: determining, in response to a first self-organizing network function instance requesting a permission to execute a corresponding self-organizing network function, a priority, an impact time and an impact area for the first self-organizing network function instance; checking (204, 206), whether or not there are one or more other self-organizing network functions scheduled to be run during the impact time of the first self-organizing network function instance and having an overlapping impact area with the impact area of the first self-organizing network function; if there are, the method further comprises: comparing priorities of other self-organizing network function instances scheduled to be run during the impact time of the first self-organizing network function instance and having an overlapping impact area with the impact area of the first self-organizing network function; and if the priority of the first self-organizing network function instance is higher than the other priorities, the method further comprises: allowing the first self-organizing network function instance to execute the corresponding self-organizing network function; and locking the other self-organizing network function instances to prevent execution of the other self-organizing network function instances. determining, in response to a first self-organizing network function instance requesting a permission to execute a corresponding self-organizing network function, a priority, an impact time and an impact area for the first self-organizing network function instance; checking (204, 206), whether or not there are one or more other self-organizing network functions scheduled to be run during the impact time of the first self-organizing network function instance and having an overlapping impact area with the impact area of the first self-organizing network function; if there are, the method further comprises: comparing priorities of other self-organizing network function instances scheduled to be run during the impact time of the first self-organizing network function instance and having an overlapping impact area with the impact area of the first self-organizing network function; and if the priority of the first self-organizing network function instance is higher than the other priorities, the method further comprises: allowing the first self-organizing network function instance to execute the corresponding self-organizing network function; and locking the other self-organizing network function instances to prevent execution of the other self-organizing network function instances. comparing priorities of other self-organizing network function instances scheduled to be run during the impact time of the first self-organizing network function instance and having an overlapping impact area with the impact area of the first self-organizing network function; and if the priority of the first self-organizing network function instance is higher than the other priorities, the method further comprises: allowing the first self-organizing network function instance to execute the corresponding self-organizing network function; and locking the other self-organizing network function instances to prevent execution of the other self-organizing network function instances. allowing the first self-organizing network function instance to execute the corresponding self-organizing network function; and locking the other self-organizing network function instances to prevent execution of the other self-organizing network function instances.