The purpose of this 2-day workshop is to study and advance the effective use of models in the engineering of software systems. In particular, we are interested in the exchange of experiences and innovative technical ideas related to modeling. Engineers have used models to manage complexity for centuries, and there is a growing body of work on the use of models to manage inherent problem and solution complexity in software development. The use of software models will become more prevalent as methodologies and tools that manipulate them at various levels of abstraction become available. A secondary goal of the workshop is to further promote cross-fertilization between the modeling communities (e.g., MODELS) and software-engineering communities. We take a broad view of what models are and how they are used, including 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. Communication: Communication models are used to document software decisions (e.g., requirements, designs, and deployment decisions). Support for downstream activities: We use software models to answer questions or check properties (e.g., correctness, fitness for use) of the modeled artifact, to generate other artifacts, or to configure existing systems. Support for downstream activities: We use software models to answer questions or check properties (e.g., correctness, fitness for 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, to adapt it to changed needs of the users. A model of the environment also allows a system to capture its knowledge about the environment it controls or communicates with. Workshop activities will focus on analyzing successful and unsuccessful applications of software modeling techniques to gain insights into challenging modeling problems, including: (1) identifying, describing, and using appropriate abstractions, (2) supporting incremental, iterative development through the use of appropriate model composition, transformation and other model manipulation operators, and (3) automated analysis of possibly large and possibly incomplete models to determine the presence or absence of desired and undesired properties.