Keith Wolken works in an unassuming office on the west side of Nashville, in a quiet, two-story brick building. The ease of Wolken’s demeanor indicates none of the stress that might be expected of the first-year chief executive officer for a booming $230 million company. After the death from a heart attack of SMS Holdings Corp.’s founder and CEO William T. Coakley last October, Wolken, who previously served as chief operating officer, was chosen to lead the company forward. Now, one year after filling his brother-in-law’s shoes, Wolken says that by following the management system Coakley put in place, he was able to move into his new position without a hitch.

With more than 12,000 employees in 46 states, the Nashville-based company manages four subsidiaries that provide housekeeping, mall security, aviation services and private airport security. The privately owned operation has grown rapidly from what Jim Burnett, executive vice president of business development and government services for SMS Holdings, says began with “one employee and no customers” in 1988. Wolken estimates that the company will reach 13,000 employees by year-end.

“Companies of that size should have an executive succession plan in place. If they don’t—which some companies like McDonald’s and Disney, in the mid-’90s, had some scares with—then a CFO would step in and continue that person’s goals on an interim,” says Earl Thomas, professor of management at Middle Tennessee State University.

Wolken says that SMS Holdings was prepared for such a transition. Coakley and his staff had hammered out a strategic plan for each subsidiary company. The success of that plan hinged on having the right leaders in place, a need that Coakley cultivated. He ensured that each company president had a strong support structure beneath him or her, all the way down to onsite managers. The result?

“That transition was pretty seamless,” Wolken says. Now, not only has the corporation survived this shift, but it’s flourishing.

“This year has been by far our strongest growth, in terms of the dollars and accounts started, in the history of our organization,” Wolken says. He expects total revenue for the year to reach $275 million, up from $230 million last year. The company’s newest client, Pennsylvania Real Estate Investment Trust (PREIT), will bring in $117 million alone over the next five years, causing SMS Holdings to add another 800 employees to the roster.

Wolken’s next goal is to break into the health care industry and to continue adding major airports to an expanding list that includes Nashville International Airport, Seattle-Tacoma International Airport and Oklahoma City Airport, among others.