These can be held as frequently as the manager and employee feel necessary, often weekly or bi-weekly.
They can all be formal, or a mixture of formal (structured with forms and notes) and informal (verbal, no notes).
At some points notes should be kept on file reflecting discussions, concerns, action plans, commitments and support required.
If at any point an employee is not performing, the 121s and the notes from these meetings may be used in evidence of support offered or commitments made.