The goal is to allow one resource to enter time with different billing types to the same JIRA issue. So, I might enter an hour to issue XYZABC-1 with a 'Underwater Basketweaving' type of work that ends up translating to a bill rate of x dollars. . Then later that day, I might add an hour of work to XYZABC-1 with a type named 'Nuclear Engineering' that translates to a bill rate of x + 5 dollars.