The 7th lord is Mars and is posted in the 12th. The nakshatra representing the 7th house is Venus. He is in its debilitation sign and in a rasi interchange with Budha. The karaka for business is Mercury who is in Lagna. In Navamsa Mercury occupies the 8th amsa from natal lagna and is with Venus. The combination is aspected by both Mars and Saturn in Navamsa. Mercury dasa will activate Jupiter who is not placed well in both Navamsa and Dasamsa.
Current dasa is of Saturn – Jupiter which is also not very favorable for business.
Overall, he may not grow the business fast and will do average in the field.