Rapp’s Parts is a small machine shop that makes custom parts for manufacturers in the metropolitan area where it is located. For 20 years, Erin was the office assistant. She was hired to fill a position that involved keeping track of customers' orders and purchasing supplies. After Erin retired, the company hired another office assistant to perform the same tasks. Soon afterward, however, the company's owner began hearing from frustrated customers complaining that when they called the company with questions and problems, no one was taking responsibility and helping them as Erin had. What problem with job analysis is most likely to have occurred when Erin retired?