Up to six months. Mine was completed in three weeks (Geneva). SEM is pretty rapid with their determination depending on the quota.

Was there any interview by the Embassy?

not for a B-permit. It's all paper submission. the canton assesses the application and supporting material from the employer sponsoring, approves or declines (assuming approved) sends it to SEM, then there is a final approval. I will attach a photo of the procedure. and the link to that. 

https://www.sem.admin.ch/sem/en/home/themen/arbeit/nicht-eu_efta-angehoerige/verfahrensablauf.html

Thank you for detailed explanation with picture. It seems like it's tough to get permit seeing the process. My employer is a big4 and they were very skeptical about visa that made me curious if it's actually something that takes time. I saw their business letter it's shown as my job under shortage list of occupation . Hope I get through this . 

Are u living in Zurich ?

Oh yes. It is rather difficult given 3rd party nationals (you and I) are 3rd in line, so to speak, regarding employment. Your employer will first have to show there were no suitable Swiss candidates for the position. Next, they will have to prove there were no suitable EU/EFTA candidates for the position. Then and only then can they justify your hiring. They will have to post the job online for at least 14 days to allow for applications. There are a few more pieces of criteria but it also all depends on the number of visas that have already been issued to third-party nationals. As there is an annual limit of 8,500 per year. 3,500 of which go to UK Nationals, if I am not mistaken. 

Thank you for numbers and information ????..one more question travel related - do you know any app or social networking group to find a travel buddy ?