sales growth.Role of Group Product Manager within Group Product & Services department. 1...The Group Product Manager (hereunder as the “GPM”) plays an important role in ensuring Lyreco’s profitable..The Group Product Manager (hereunder as the “GPM”) plays an important role in ensuring Lyreco’s profitable..The Group Product Manager (hereunder as the “GPM”) plays an important role in ensuring Lyreco’s profitable..He/she supports their Group Category Manager in the strategy definition. 3.