By 2014, Nokia's global brand value according to Interbrand fell to 98th place, a sharp slide from the 5th place it was in 2009. Nokia's downfall in the mobile phone market has had different explanations from analysts, with many split about the CEO's decision to abandon its in-house operating system and adopting Windows Phone in 2011. Many researchers have concluded that Nokia suffered from deep internal rivalries within the management. Former employees claimed that the management became so swollen by the early success that they grew complacent over time. Some from the Symbian developing team have claimed that the company's upper management rejected hundreds of potential innovations during the 2000s that they proposed, including entirely rewriting Symbian's code. One former Nokia employee claimed that the company was run as a "Soviet-style bureaucracy".