This paper deals with group creativity, i.e. production of originality through combination of differences, and suggests a model for assessment of innovation maturity, i.e. group maturity, in relation to work task characteristics vis-a-vi a shared content, i.e. group ideas. The process of generating original ideas and develop that kind of ideas in work group is defined as a complex activity, i.e. the co-operation of several mutually deviant factors such as combination of different knowledge areas, intensity of idea exchange and critical evaluation. This research is conducted from the perspective of a team paradigm which means that group creativity and group dynamics are studied in the team's day-to-day work setting in order to develop an understanding of the competence and abilities at group level in relation to the tasks characteristic. In line with that perspective we propose that the team’s innovation quality should be understood and described in relation to the shared content evolving from team member’s interaction, i.e. the group idea. Furthermore, by taking a complex systems perspective, the team can be understood as an entity that can develop certain traits as well as inter-subjective competences. Results from a questionnaire study, conducted in the framework of an ongoing evaluation and research project in the public sector in Sweden, with 80 respondents form the initial basis for the development and evaluation of a model for the assessment of maturity for team-based innovation. The analysis of questionnaire data confirms the positive relationship between group performance, i.e. the production and development of creative ideas on the one hand and the quest for originality combined with critical analysis and evaluation on the other hand. Analysis of data from two of the four working groups also show that encouraging climate and extrinsic motivation, often considered to have major importance for creative performance, do not necessarily have that effect on idea generation and idea development.