Complex sentence: Over the next year and a half he worked on a series of initiatives to strengthen the company; in a back to basics campaign, he oversaw a streamlining Burger King's menu and worked to improve and strengthen relations with franchisees.
Split into simpler sentences: Over the next year and a half he worked on a series of initiatives to strengthen the company. In a back to basics campaign, he oversaw a streamlining Burger King's menu and worked to improve and strengthened relations with franchisees.