This textbook is intended for use by SPI (Software Process Improvement) managers and researchers, quality managers, and experienced project and research managers. The papers constitute the research proceedings of the 15th EuroSPI (European So- ware Process Improvement, www.eurospi.net) conference in Dublin, Ireland, 3-5 September 2008. Since the first conference, held in Dublin in 1994, EuroSPI conferences have been held in 1995 in Vienna (Austria), in 1997 in Budapest (Hungary), in 1998 in Goth- burg (Sweden), in 1999 in Pori (Finland), in 2000 in Copenhagen (Denmark), in 2001 in Limerick (Ireland), in 2002 in Nuremberg (Germany), in 2003 in Graz (Austria), in 2004 in Trondheim (Norway), in 2005 in Budapest (Hungary), in 2006 in Joensuu (Finland), and in 2007 in Potsdam (Germany). EuroSPI has established an experience library (library.eurospi.net), which will be c- tinuously extended over the next few years and was made available to all attendees. EuroSPI has also started an umbrella initiative for establishing a European Quali- cation Network in which different SPINs and national ventures can join mutually beneficial collaborations (EQN - EU Leonardo da Vinci network project). With a general assembly on 15.-16.10.2007 through EuroSPI partners and n- works, in collaboration with the European Union (supported by the EU Leonardo da Vinci Programme), a European certification association has been created (www.- certificates.org) for the IT and services sector to offer SPI knowledge and certificates to industry, establishing close knowledge transfer links between research and industry.