Requirements Engineering has recently been greatly influenced by the way how firms use Open Source Software (OSS) and Software Ecosystems (SECOs) as a part of their product development and business models. This is further emphasized by the paradigm of Open Innovation, which highlights how firms should strive to use both internal and external resources to advance their internal innovation and technology capabilities. The evolution from market-driven requirements engineering and management processes, has reshaped the understanding of what a requirement is, and how it is documented and used. In this work, we suggest a model for analyzing and managing requirements that is designed in the context of OSS and SECOs, including the advances and challenges that it brings. The model clarifies how the main stages of requirements engineering and management processes can be adjusted to benefit from the openness that the new context offers. We believe that the model is a first step towards the inevitable adaptation of requirements engineering to an open and informal arena, where processes and collaboration are decentralized, transparency and governance are the key success factors.