Starbucks Corp. has appointed Kevin Johnson as president and chief COO, effective March 1. He replaces the company's current COO, Troy Alstead, who will take a sabbatical beginning March 1. Johnson, a Starbucks board member since 2009, served as CEO of Juniper Networks from 2008 through 2013. Prior to that, he served as the president of the Platforms Division at Microsoft Corp.