Apple's latest Supplier Responsibility Report has just been published, detailing 339 audits focused on the plants and suppliers that help make all that hardware. The audit number is a 72 percent increase in what it covered in its last annual report, while Apple was also quick to highlight its contracting companies' high compliance (92 percent) with a maximum 60-hour work week. Senior vice president of operations Jeff Williams told Reuters that underage workers and limiting working hours were two of the most challenging issues it faced in its supplier audits. Apple decided to end business relations with component maker Guangdong Real Faith Pingzhou Electronics over underage labour issues. "We go deep in the supply chain to find it," said Williams. "And when we do find it, we ensure that the underage workers are taken care of, the suppliers are dealt with."