John Chen, the man who proved doubters wrong after turning Sybase around and selling it to SAP for $5.8 billion, is now facing the biggest challenge of his career: repeating history with BlackBerry. The newly appointed CEO of the struggling mobile maker is facing the daunting task of staging a comeback in a market dominated by two of the most disruptive tech firms in the industry.

The first phase of Chen’s plan to catch up with Google and Apple is a management reshuffle, which started with the Tuesday appointment of John Sims as the president of BlackBerry’s Global Enterprise Services business. The executive previously served as president of SAP’s Mobile Services division, the same position Chen held after the acquisition of Sybase.

“I am pleased to welcome such a seasoned executive as John to BlackBerry to help lead our key business operations through our ongoing reorganization and transition,” Chen said in a statement. “His extensive experience in transforming businesses, redefining brands and motivating teams will be a tremendous asset to BlackBerry as we reshape the company to be more nimble and focused.”

The next day, the CEO brought two more of his SAP colleagues aboard. The first is James Mackey, the business intelligence giant’s former head corporate development. As the executive vice president for corporate development and strategic planning, he will play an instrumental role in executing Chen’s turnaround strategy. Also joining the company is Mark Wilson, who will serve as the head of marketing. He previously held similar posts at Avaya and Sybase, where he worked for over a decade.

“I have worked extensively with both of them in the past, have the utmost respect for their experience and accomplishments, and we have developed close and trusted relationships with each other that will enable us to cohesively manage the changes required to reshape BlackBerry,” Chen said.