The scale and complexity of the modern manufacturing systems make essential the integration of predictive simulation modelling and optimisation methodologies into routine decision making processes. To address this challenge, DREAM will offer a radically new and extensible approach to simulation application engineering, leveraging state-of-the art research on simulation and simulation based optimization.The objectives are:1. To increase the competitiveness of European Manufacturing Companies through the provision of multi-level just-in-time simulation based application decision support.2. To engineer a semantic free open simulation application development platform to promote simulation based applications by European Manufacturing Companies, IT consultants, Open Source community and Researchers.3. To address the multi-faceted barriers to the adoption of advanced simulation decision support technologies by manufacturing companies, especially SMEs, by developing methodologies to address system knowledge management and human-system interaction challenges.4. Using the semantic free simulation application platform to implement novel applications to support decisions at multi-levels in European Manufacturing Companies.The expected impacts of the DREAM:1. Wider adoption of Simulation Decision Support Applications by manufacturing companies (and especially SMEs due to lower entry costs) in Europe, resulting in lower cycle times (15%) and improved customer service levels (20%).2. Adoption of DES Decision Support across all decision levels of manufacturing resulting in first-time-right process decisions (30% improvement) and greater capability to react to external and internal changes (reduction in reaction time by 25%);3. Through the provision of the Open DREAM Simulation Development Platform the establishment of a community focused on the development of simulation based applications to support European manufacturing companies.