MIMS for TRIM

The Multimedia Integrated Modeling System (MIMS framework was designed and developed by the U.S. EPA Office of Research and Development. MIMS supports complex computational studies that use multiple interrelated models / programs, such as the modules within TRIM. MIMS is used by TRIM to run various models in sequence, while sharing input and output files.

The integration of the TRIM models and other programs is accomplished using a MIMS Project. A MIMS project serves as a container for all of the building blocks used in a study, such as the software programs (modules) to be run and scenarios that specify how the models communicate with one another. The MIMS approach differs from that of the model-centric frameworks because the MIMS modules do not conceptually communicate directly with one another like traditional models, but only through shared interfaces called domain objects, or via shared databases or files. Below are definitions of some important concepts used by MIMS.

• The Project is the outermost container in MIMS. The project contains various categories of building blocks that will be used in a study, such as modules, domain objects, and scenarios.
• A Scenario connects the MIMS building blocks (domain objects, processes, modules, and parameters) into a particular configuration to perform one or more model runs.
• A Module is a software program (and supporting information) to be executed by the MIMS framework. Modules are typically simulation models (e.g., TRIM.Expo-Inhalation (APEX), TRIM.Risk-Eco).When a module is used to implement a process within a scenario and domain object, a copy of it is made that is known as a Module Instance.
• A Parameter is a piece of information (e.g. a file name, true/false value, a grid) that is used by a MIMS building block. Parameters are used by Scenarios, Modules, Domain Objects, etc.
• A Domain Object represents a concept, thing, or part of the environment to be modeled (e.g.., atmosphere, population, stream). The domain object contains both the information describing itself (in the form of parameters), and its behaviors (in the form of processes and the modules that implement them).
• A Framework Object is an operational component such as an Iterator within the MIMS Scenario. The tasks of framework objects are typically independent of the environmental models and instead represent computational functions, such as when an iterator advances time steps or loops over the items in a set of input parameters.

Instructions for using MIMS for TRIM will be provided in Volume 1 of the TRIM.Risk User’s Guide. Additional information about MIMS concepts and how to navigate a MIMS project is available in Chapters 1 and 2 of the "MIMS for Models-3 Applications Tutorial."