The systematic definition and management of requirements is becoming increasingly important in product development. Many software organizations are interested in improving their requirements engineering processes but they do not know where to begin. Sommerville et al. have developed a framework known as the Requirements Engineering Good Practice Guide (REGPG) for incremental process improvement. We applied the REGPG in four Finnish organizations and evaluated its strengths and weaknesses. The most important strengths of the REGPG are that it raises personnel awareness of requirements engineering and it includes relevant requirements practices allowing organizations to select practical improvement actions. The main weakness of the REGPG is that it offers a very limited set of general process improvement guidelines. Therefore, organizations that want to develop their requirements engineering processes systematically need to support the use of the REGPG with other improvement frameworks.