The use of the passive voice is usually avoided except for scientific articles and administrative procedures. This appears to be a text for administrative procedures, so the passive voice is normal. In my experience as a manager in a large company in the 1990s and 2000s, there was a move away from the passive voice. Active voice text is shorter and easier to understand. Most people would say there is no difference between the versions. I see a slight difference and prefer the simple present. The present perfect has the sense of verifying that company policy has been followed during certain time periods. Example: For project X (exceptionally), monthly audits will be conducted to verify that company policy has been followed. The present simple has the sense of verifying that company policy is being followed in general. Example: For all projects, monthly audits will be conducted to verify that company policy is being followed.

b) Periodic audits can be conducted to ensure that the required documents are completed and employee interviews are conducted in accordance with the company policy. Present Simple tense.

I think they're both fine, though I would probably use the present perfect myself. The bit that does not sound right to me is "can be". I would say " may be"