The bottom line is that the team's cars just aren't up to spec, and the blame has apparently fallen on its technical chief Aldo Costa. He's held the job since 2007, but will now relinquish the role as the team comprehensively restructures its technical department. Rather than hire or promote someone to fill Costa's position, Pat Fry, Luca Marmorini and Carrado Lanzone – the individual heads of the chassis, engine and production departments, respectively – will now report directly to team principal Stefano Domenicali.
More or less sums it up. You can find the full article here.