PLYMOUTH, MICH. -- A key to Chrysler Group's return to profitability is a plant performance improvement program developed by parent company Fiat SpA (IW 1000/87) , said Mauro Pino, the company's head of World Class Manufacturing at the Machines Italia manufacturing 3.0 conference in Plymouth, Mich., Thursday, June 21, 2012 Chrysler first implemented Fiat's program, called World Class Manufacturing , three years ago as a continuous-improvement system focused on all plant processes, including safety, maintenance and quality. As an offshoot of the program, Chrysler opened in January a learning