Software applications for manufacturing systems developed using software from different vendors typically cannot work together. Develop¬ment of custom integrations of manufacturing software incurs costs and delays that hurt industry productivity and competitiveness. Software applications need to be tested in live operational systems. It is impractical to use real industrial systems to support dynamic interoperability test¬ing and research due to: 1) access issues - manu¬facturing facilities are not open to outsiders, as proprietary data and processes may be compro¬mised; 2) technical issues - operational systems are not instrumented to support testing; and 3) cost issues - productivity suffers when actual production systems are taken offline to allow testing. Publicly available simulations do not exist to demonstrate simulation integration issues, validate potential standards solu¬tions, or dynamically test the interoperability of simulation systems and other software applica¬tions. A new, dynamic, simulation-based interoperability testing facility for manufacturing software applications is being developed at the National Institute of Standards and Technology (NIST).