Models have long been used in the development of complex systems. Their use is becoming more prevalent in the software development domain as modeling techniques and tools mature. Despite this, there are many challenging issues that the modeling research community must address if software modeling practices are to become mainstream. Furthermore software and systems become more intertwined and the modeling techniques used for systems engineering need to be harmonized with software models. The primary goal of this workshop is to foster exchange of innovative ideas on the use of models in software engineering. Another goal of this workshop is to further promote cross-fertilization between the model-driven engineering (MDE) communities (e.g., MODELS) and software-engineering communities. Previous versions of the workshop showed that while there is great interest in collaborations and discussions across these communities, there are differences in terminologies and concepts that need to be harmonized for effective communication to take place. To ensure that discussions at the 2015 workshop progress beyond the basic alignment of concepts, potential workshop participants will be encouraged to familiarize themselves with the papers presented at the previous and current MiSE workshop in the calls for papers and for participation. The workshop provides a forum for discussing and critically analyzing modeling techniques with respect to their purposes in software engineering processes. Participants engage in the exchange of innovative technical ideas and experiences related to modeling, including modeling notations, abstraction techniques, modeling strategies, and use of models in development activities, including system configuration, system simulation, testing, and product line variability management. The purpose of a model and the domain it describes determine the types of abstractions that are useful and the degree of formality and precision needed. We identify the following major purposes of software modeling: Exploration: Models are used to explore and learn about the problem to be solved, where the “problem” can be, for example, requirements identification, system specification, system or component design, complex protocol or algorithm design. Of particular interest is the use of models to enable “what-if?” analysis and prognostics (e.g., prediction), such as via models of ‘big data’. Communication: Communication models are used to document software decisions (e.g., requirements, designs, and deployment decisions), or to enable discussion, conversation and negotiation between different stakeholder groups with different perspectives, vocabularies and needs.. Support for downstream activities: We use software models to answer questions or check properties (e.g., correctness, fitness of use) of the modeled artifact, to generate other artifacts, or to configure existing systems. Configurability and adaptation: We use models at runtime to configure the system and adapt it to changed needs of the users. A model of the environment also allows a system to capture its knowledge about the context it controls or communicates with.