I applied through a staffing agency. The process took 3 days. I interviewed at Adecco (DeKalb, IL) in Jun 2014
Interview
after applying online. you receive a call about testing dates. Upon deciding on which day to test you notify them and you show up at their facility for the test. They do not give you any material to prepare for the test beforehand. Math and physics test at their facility after which you passed, you got hired