There is a common misconception that divorce in Switzerland necessarily takes a long time because of a mandatory, extended period of separation. However, this is not the whole picture.
If both parties agree to divorce, they need not first live separately. This is divorce by joint application. They need not agree all consequences; mutual agreement to end the marriage suffices.
If only one partner wants divorce and the other firmly opposes it, joint divorce is unavailable. The willing partner must bring a claim, preceded by two years of actual separation. The sole exception is where continuing marriage is unreasonable despite this separation. Strict criteria apply, such as physical or sexual violence.
In summary: If both partners agree divorce is right, no separation period is prescribed. If only one wants divorce, separation for 2 years is generally required before legal proceedings.