The people who have to make it work need to agree to it.
Realistic
The person has to believe it is possible to achieve. This will depend on:
The resource the person has I has access to.
The confidence the person has in themselves.
Time-specific
Deadlines for achieving each stage should be set. The ultimate goal can also be given a deadline. These should be in the foreseeable future. Small enough to be handled. Large enough to show results.
Supportive back-up
A helping relationship is useful for all stages of change and the details of what kind of support is on offer needs to be clearly spelled out.