I applied online. The process took 1 day. I interviewed at Rolls-Royce (Derby, England) in Nov 2009
Interview
ONLINE APPLICATION
ASSESSMENT CENTRE
General interview with a personal presentation to prepare.
Technical interview. Both with two people from the company.
Group exercise.
Two kind of tests: reading and numerical test.
You train on the internet before taking the actual test the day of the assessment.
They asked to explain some engineering concept with simple words. You can get something like bending in a plan wing, how an turboengine works and so on