Sustainability transitions are long-term processes that may take decades to unfold. Historically, they have been viewed as mostly emergent processes unfolding without explicit or organized order through individuals or entrepreneurs exploiting commercial opportunities offered by a new technology. As these transitions are systemic changes, there are both barriers and enablers within the system affecting these changes. This chapter focuses on identifying barriers and enabling factors through a multilevel perspective lens. We identify barriers related to the landscape, regime actors, and niche actors on the organizational level and in concert with other niche or regime actors on the interorganizational level. We also investigate enabling factors, focusing on the sustainability transition in food packaging in Finland. We consider collaboration a key enabler among actors within the multilevel perspective framework and consider how different actors enhance the transition.