Firstly a rather in depth online application and then online testing.
Once you have past these and been reviewed you are invited to an assesment day at Rolls-Royce.
This day includes
Two x 1 hour interviews (one technical, one competencies) including a 10-20 minute presentation about yourself
1 test (normally maths based) of 40 minutes
A 40 minutes case study test
And a hour group exersice task which you are observed upon.
It is a full day (8am - 4pm) and after the assesment center, you are then told within 2 days if you have been ofered a position or not.