Here’s one explanation why software firm SAP has become one of the world’s leading technology companies over the years: it is a great place to work.

SAP recently was named Germany’s best workplace in the category of companies with more than 5,000 employees by the Great Place to Work Institute Germany. The award marks the fourth consecutive year the Walldorf, Germany-based firm has taken top honors in the contest. SAP, which is one of the biggest sellers of HR software in the world, also was honored as one of the 25 best companies to work for in Japan this year.

If there remain doubters that a positive work climate corresponds to sound business results, consider a recent study from a University of Pennsylvania researcher. Finance professor Alex Edmans found that companies cited as good places to work earn stock returns that are more than double those of the overall market. In particular, companies on Fortune magazine’s annual list of the 100 Best Companies to Work for in America between 1998 and 2005 returned 14 percent per year, compared to 6 percent a year for the overall market.

SAP has its critics, and it is locked in a fierce battle with Oracle in the business software market. But over the long haul, it seems to have learned how to adapt. For example, SAP’s old reputation for arrogance (as in, SAP means Shut Up and Pay) has faded and the firm has become a much humbler organization in tune with today’s business focus on collaboration.

Part of SAP’s software success involves learning from its own experience. In an interview a couple years ago, SAP HR head Claus Heinrich told me his operation acts as a lab for the firm. Heinrich has pushed SAP software product managers to include features ranging from a 360-degree feedback process to online pay stubs.

Another key, it seems, is treating its talent as a top priority. As long as SAP keeps winning prizes as a great place to work, I wouldn’t bet against it remaining in the top echelon of the tech world.