Martin Whitmarsh admitted that McLaren needed a reality check at the end of the 2013 season in order to prepare better for next year.
McLaren endured arguably their worst season since 1980 when they failed to record even a single podium finish in 2013 and finished fifth in the Constructors' Championship with less than half the amount of points as fourth placed Lotus.
The Woking squad has made several changes ahead of the 2014 season, however.
Former Sauber chief designer Matt Morris was recruited, while Red Bull aerodynamics expert Peter Orodromou will join McLaren in 2015 when they will partner with Honda.
Mexican driver Sergio Perez was also replaced after one season, with
Formula Renault 3.5 champion Kevin Magnussen given the opportunity to partner Jenson Button.
"Failure is a painful thing but a kick up the pants sometimes you need it personally and the organisation needs it," Whitmarsh told Autosport.
"I am an optimistic type of fellow, so I come out of it and say, 'I didn't like that much', but looking to the future it has made us make some decisions that would have been difficult to make last winter because, until Australia, we thought we were as good as anybody.
"The majority cannot sit there and say we don't need to change or we have done a good enough job, because we haven't.
"Change in this environment is quite a lot easier, and change is essential in any organisation whether it is on top of its game or not.
"It is just more difficult to implement when it perceives itself to be on top of its game.
"The fact is if the wheel falls off, it is my fault. If the car is not good enough, it is my fault. If the driver makes a mistake, it is my fault.
"People talk about the pressure, but most of the pressure is internal."
Although a dramatic improvement in form in just one season is unlikely, Whitmarsh is confident that the partnership with Honda will bring more titles to McLaren.
"With the Honda deal, we know we are going to be here as a top team in 10 years," he added.
"We have secured that, and there are not that many teams that have got a secure commercial future in the way that we have."