Open source software ecosystem modelling has emerged as an important research area in software engineering. Several models have been proposed to identify and analyse the complex relationships in OSSecosystems. However, there is a lack of formal models, methodologies, tool support, and standard notations for OSS-ecosystems. In this paper we propose a general framework for support the OSSecosystems modelling process. This framework will allow the representation, synthesis, analysis, evaluation, and evolution of OSS-ecosystems. Design science methodology is proposed to create several artefacts and investigating the suitability of these artefacts in the OSS-ecosystem context. Abstract. Open source software ecosystem modelling has emerged as an important research area in software engineering. Several models have been proposed to identify and analyse the complex relationships in OSSecosystems. However, there is a lack of formal models, methodologies, tool support, and standard notations for OSS-ecosystems. In this paper we propose a general framework for support the OSS-ecosystems modelling process. This framework will allow the representation, synthesis, analysis, evaluation, and evolution of OSS-ecosystems. Design science methodology is proposed to create several artefacts and investigating the suitability of these artefacts in the OSS-ecosystem context.