On 3 November 2011, the first eight trains of the new MP 05 rolling stock were put into service on Line 1. These trains ran alongside the MP 89 CC rolling stock until enough automated stock was available for passenger service. This cascading was achieved thanks to the SAET () system, which is the first version of Siemens Transportation Systems' Trainguard MT CBTC. The arrival of the new stock allowed the RATP to accelerate transfer of the MP 89 from Line 1 to Line 4 at a rate of about 2 to 3 trains per month between November 2011 and November 2012. That rate increased to 4 trains per month during November and December 2012.