In modern physics, the evolution of computational capacity allows materials to be investigated over a wide range of length and time scales, often referred to as multi-scale materials modelling (MMM). This allows for the modelling of complex materials under realistic constraints in a wide range of situations. Almost all MMM discussions take a bottom-up approach, starting from ab-initio density functional theory [1] and linking upwards via higher level models to predict key material properties at the micro- or nano-scale [e.g. 2,3]. From the other side, Integrated Computational Material Engineering (ICME) starts from the application requirements, and aims to understand how processes form material structures, how these structures give rise to material properties and how to select proper materials for applications based on this information. ICME uses computational engineering as a major component aiming to remove the need for a lot of experimentation. The aim is to design products alongside the materials that comprise them, and the end result is sought from investigations and simulations at multiple length scales during the product and process development [4]. A review of these issues can be found in [5].

 The main challenge, both in MMM and ICME, is the coupling and linking of models describing phenomena at different scales, from the nano-scale up to the device [6] or macroscopic scale. This workshop aims to bring these two communities together to discuss in detail the challenges to be met in the structuring and realisation of integrated frameworks that facilitate linkage of various multi-physics models to achieve the predictive design of novel materials optimised for specified applications. About one third of the invited speakers have been chosen because of their roles either as industry end-users or as commercial software producers.

Current computational tools typically have their own non-standard schemas for input and output files, including also varying definitions of the model. At the same time, different communities often rely on distinct nomenclature to describe the same model components or physical parameters, which makes it even harder to link and couple disparate tools. 

Many multiscale problems require the linking of several levels of code, that span several research and application communities, and including open-source and commercial packages. Some existing tools use their own metadata schemas. Though these schemas are themselves distinct, translating from one to the other is often time consuming and inefficient. In addition, large quantities of data are being generated across different platforms, much of which is potentially useful and re-usable by the wider community, but often in ways that are not immediately obvious in the original context. 

A crucial challenge then is to work towards enhanced interoperability, both across different codes and also across different communities. The workshop will bring together key speakers and groups that are addressing that challenge, to engage in practical discussions regarding what has been achieved to date and to roadmap the key steps to facilitate interoperability across the full spectrum of MMM and ICME applications.

With the large European and worldwide investment in multiscale simulation, the time is now ripe to organise a workshop where MMM and ICME researchers can exchange approaches, move towards some standards and present progress to the communities of both academic and industrial researchers. 

Specific topics to be addressed include how to:

1. Support best practices: sharing what works among those involved in this type of work.
2. Reduce redundancy: what tools and frameworks are available and how reuse can be done most effectively.
3. Develop standards: discussion of where standardization is needed will greatly increase efficiency of the platform tools being developed, and their interoperability.
4. Integrate databases: avoid redoing calculations, increase standardization and data compatibility, provide opportunities for data mining. 
5. Roadmap key needs: seek community agreement about what tools are most critical to develop, routes to interoperability and to platform sharing, and how to move forward most efficiently - may require a cooperative effort across different communities to be realized.
6. Build expertise: sessions devoted to hands-on overview, training and comparison of different platforms and linkage approaches.

To achieve these goals, this three-day workshop is structured so that: 
• Day 1 sets the scene regarding the current status and vision for multiscale simulation, including the perspective of the multiscale materials modelling and the Integrated Computational Material Engineering communities, with keynote talks from recognised research leaders, and a panel discussion on interoperability to conclude the day and set the stage for the two following days
• Day 2 shares current practice, with a hands-on poster and demo session for the morning (PlugFest), including training and comparison of different platforms and linkage approaches being undertaken; followed in the afternoon by presentations and discussions from a cluster of EU-funded multiscale simulation projects regarding current developments and challenges for interoperability
• Day 3 addresses next steps and challenges, with a series of overview presentations on Roadmaps, future plans and directions for integration being used to set the scene for chaired open discussions to identify and agree critical next steps for the widespread uptake of Multiscale Simulation going from Materials Modelling through to Industrial Usage.

Outcomes of the meeting:
• Progress in addressing challenges in multiscale simulation
• Coupling and linking between “bottom-up” and “top-down” communities
• Building critical mass/consensus towards development of best practice and standardisation
• European leadership in this important area of multiscale simulations from first principles through to industrial applications