(TIME) -- When Jeroen van der Veer was thrown into the top job at Royal Dutch Shell, in the midst of a major crisis following disclosures that the company had overstated oil reserves by more than 20%, he scribbled down three key issues to address with his colleagues: "Reserves, keep eye on the business, and culture/structure." But in the eight months since, Van der Veer, 57, has done a lot more than those jotted notes suggest. He has radically overhauled Shell's management and governance structure. After months of discussions with regulators and institutional investors, Shell announced in November the full merger of its two parts into a single company with a single board and one chief executive. Shell has been fined by regulators and still faces numerous lawsuits, but even the most critical investors are applauding the speed and boldness with which the CEO faced the crisis. "He deserves a lot of credit," says Eric Knight of Knight Vinke Asset Management, which, together with the California state retirement fund Calpers, led the push for change. Shell stock has rebounded, and it's now well above where it was before the crisis began. Will Van der Veer be as forceful in less turbulent times? His perspective: a unified Shell under one leader will be more accountable - and a more effective competitor. "We sometimes had the right ideas and were early with trends," he says, "but we were slower to execute them than our competition." Not anymore, he vows. --By Peter Gumbel