What is the BVG? Find it explained here.
The Federal Act on Occupational Retirement, Survivors' and Disability Pension Plans (BVG) governs the mandatory occupational pension, the 2nd Pillar of the Swiss pension system. Combined with the 1st Pillar, the benefits should total around 60% of your last salary. In order to maintain the standard of living that you are accustomed to, you also need a private pension (3rd Pillar.)