Travel Switzerland - Taiwan - Shanghai - Switzerland

You are definitely eligible for 144 hours visa free transit upon your second arrival in Shanghai and you can stay up to 6 days visa free. I assume that during your first arrival in Shanghai, you will just make a transfer from one to another flight and will stay for less than 24 hours there, right? In case that your first arrival in Shanghai will last less than 24 hours, in that case you will be covered by 24 hours visa free transit. Also, I hope that you have left at least 3 or 4 hours between the flights in Shanghai in order to be comfortable in meeting the formalities and transit hassles. Also, keep in mind that your flights to and from Shanghai should not have any additional landing(s) within mainland China.