It is only wise to carefully examine whether your company is ready to adopt OKR before investing a lot of time and energy into it.
On average, teams we coached reported that they started to notice the benefits in 6-8 weeks (kudos to them!).
Read some excerpts of their conversations here.
A typical sign that OKR is a good fit for your company is to have 1-2 teams reporting real benefits before other teams catching up.
Let's approach this question from the another angle:
How long to find out whether OKR is not a right option?
One recurring pattern that we have witnessed that hindered (or completely incapacitated) the adoption of OKR is the absence of leadership role.
This can be as simple as the management doesn't review the top-line OKR timely, or frequently change KR in the middle of a quarter in the name of chasing unique business opportunity.
This emits a strong signal that the leadership doesn't care much.
Marty Cagan, a highly respected Product thought leader, shared the same sympathy in this article (point no.3):
"... really the root of the problem, is that in the vast majority of companies I see that are struggling to get any value out of OKR’s, the role of leadership is largely missing in action"
OKR after all is a leadership exercise.