Basic application form followed by i think online tests. scheduled a telephone interview which was basic questions about why mars and why the role with some competency questions. Couple days later invited to assessment centre in Slough. only 3 of us at the assessment centre, first was a group debate/discussion about a short case we read. then individual case study which was quite difficult because only had a short amount of time to prepare recommendations and justifications. quite a lot of questioning for that. Final interview, mostly competency based, some questions quite tough but quite straightforward if you prepare.