It took three years of hard work to refit the production site in Kragujevac, central Serbia, and make it operational to start production of the Fiat 500L. To achieve this goal, starting in 2010 the Turin-based group invested more than 1 billion euros, and provided know-how to over 2,000 workers through 1,100,000 hours of training. Thus creating a new industrial culture in the country. With operations in Serbia first dating back to 1953, in partnership with the Zastava group, Fiat has managed to develop a manufacturing complex that is at the cutting-edge in terms of infrastructure, production machinery and systems. The factory covers an area of 1.4 million m2, and has an output of 200,000 cars a year, made using technological platforms that can also support other production cycles, simplify maintenance, reduce energy consumption and ensure vehicle quality. All this of course also depends on process quality: the walls, roof and floor of the bodywork area are all assembled with maximum precision, the systems are large and uncomplicated to simplify maintenance, ensuring high performance and reliability. The Serbian plant has also been developed according to the concept of environmental and human sustainability. As well as having planted 1,000 local-variety trees in the factory area and created a bio-lake that hosts several endangered species, the Fiat Biodiversity Value Index has been adopted: this index measures the relationships involving human activities and biodiversity. However, comfort at the Fiat plant in Serbia is also the result of the work done by Sabiana. To meet customer requirements, the company made 200 customised Sabiana unit heaters for heating the Kragujevac plant, applying criteria that guarantee maximum efficiency in terms of energy consumption and performance. In addition, 300 standard Sabiana unit heaters were also installed, which by offering flexibility in controlling the water temperature, provide supply temperatures similar to body temperature. This is why Sabiana, which has been making unit heaters since 1935 and exports them to over 40 countries, is the European leader.