First you have the classical tests, numerical and verbal reasoning. If you pass you have to do a Siru interview, which basically consists on you answering questions. The felling that I got was that it went worse than reality.
Ultimately, if you pass all this steps you will be invited to an assessment centre.
This assessment centre was a hell of an experience ! It was great opportunity to meet people and to visit GSK HQ.
The 5 tasks that you have to do during the assessment are: 2 Group dynamic, 1 role play activity, 1 presentation and 1 interview.
Make sure you study the vision of GSK and participate with quality in all activities.