How often shall we do this kind of review?

Leadership Feedback is designed to be used multiple times over a year, ideally three to four times. It is not intended as a “one off” truth teller of who is a good leader and who is not. The value of the product is in the insights it can give individual leaders and organizations over time. Of course, this also depends upon the specific circumstances for your organization and purposes – it could be used one time but then the potential value would be much lower in terms of positive organizational outcomes (higher performance, increased engagement, better managed culture and accelerated strategy).