BASF developed the eco-efficiency analysis as a tool in 1996 together with the Roland Berger consultancy. The eco-efficiency analysis is a method that comprehensively evaluates products and processes. Many different economic and ecological data are entered onto a two-axis graphic (portfolio). Costs are shown on the horizontal axis, while environmental effects are shown on the vertical axis. This graphic enables comparison of the eco-efficiency of various products or procedures. The instrument is also used by Akzo Nobel. BASF has carried out over 400 eco-efficiency analyses and also offers its customers this instrument. The BASF method has been certified by TÜV Rheinland Berlin-Brandenburg since 2002 and by the US National Sanitation Foundation since 2009.