McLaren's new chief engineer Peter Prodromou said it was clear the team had "lost its way" when he joined from Red Bull last year.
Prodromou came to McLaren at a time of transition with the arrival of new engine supplier Honda as well as an overhaul in the way the team approaches car design. Prodromou said the old way of working was limiting the car's overall potential.
"Over the last couple of seasons, the team slightly lost its way aerodynamically," he said. "It became obvious that if we'd carried on with the previous concept, there'd only be so much we could achieve. So we've begun to establish a new aerodynamic concept, and a different way of working, too. That new concept has majorly shaped where the team's heading in the future.
"Next year's car will be an evolution of this year's, so we need to keep developing it right until the final race."
Racing director Eric Boullier said McLaren's new approach this year has also improved the success rate of updates on the car.
"There's been a huge change in overall culture and philosophy," he said. "At every level of the company, there is clear leadership. We agree the direction we want to pursue, and we bring people with us. The attitude has changed from 'telling' people, to 'asking' people; we've integrated people, and we share opinions and ideas.
"The main outcome of that new approach is that people now have a sense of ownership in the car. And they're more motivated and interested as a result. To give you an example, I guess about 50% of the upgrades we brought to the track last year didn't completely work; this year, we've brought that down to about five or 10%."