Reference #232: The First 90 Days
No matter your business situation. Creating a 90-day plan and getting buy-in from your boss is useful.
The first 30 days should be devoted to learning and building credibility.
In the next 30 days, you should tackle early wins and start to make progress towards your goals based on the situational diagnosis.
The final 30 days should see you continuing to focus on your goals, informed by your progress at the 60 day mark.
Watkins. The First 90 Days, 2013. (109-110)