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Systems Modeling & Simulation Working Group

The following was compiled by members of the Systems Modeling & Simulation Working Group to provide the model-based systems engineering community with a common set of shared terms and definitions.

A-C | D-F | G-I | J-L | M-O | P-R | S-U | V-X | Y-Z

Terms & Definitions (M-O)


Term Definition Source Comments
Mathematical Model A symbolic model whose properties are expressed in mathematical symbols and relationships. (IEEE 610.3-1989) Modeling & Simulation Coordination Office
Measure Of Effectiveness (MOE) A metric used to quantify the performance of a system, product or process in terms that describe a measure to what degree the real objective is achieved. Modeling & Simulation Coordination Office
Measure Of Outcome (MOO) A qualitative or quantitative measure that defines how operational requirements contribute to end results at higher levels, such as campaign or national strategic outcomes. Modeling & Simulation Coordination Office
Measure Of Performance (MOP) A qualitative or quantitative measure of how the system/individual performs its functions in a given environment (i.e., number of targets detected, reaction time, number of targets nominated, susceptibility of deception, task completion time). It is closely related to inherent parameters (physical and structural) but measures attributes of system behavior. Modeling & Simulation Coordination Office
Measures of Effectiveness Data Data provided to quantify Measures of Effectiveness. INCOSE
Measures of Effectiveness Needs The “operational” measures of success that are closely related to the achievement of the mission or operational objective being evaluated, in the intended operational environment under a specified set of conditions (i.e., how well the solution achieves the intended purpose). INCOSE
Measures of Performance Data Data provided to quantify the Measures of Performance. INCOSE
Measures of Performance Needs Key performance characteristics the system should have when fielded and operated in its intended operating environment. INCOSE
Metadata Information describing the characteristics of data; data or information about data; descriptive information about an organization's data, data activities, systems, and holdings. For example, discovery metadata is a type of metadata that allows data assets to be found using enterprise search capabilities. (DoDD 8320.02) Modeling & Simulation Coordination Office
Metamodel A model of a model or simulation. Metamodels are abstractions which use functional decomposition to show relationships, paths of data and algorithms, ordering, and interactions between model components and subcomponents. Metamodels allow the developer to abstract details to a level that subject matter experts can validate. Modeling & Simulation Coordination Office
Mock-Up A full-sized model, but not necessarily functional, built accurately to scale, used chiefly for study, testing, or display. Modeling & Simulation Coordination Office

Model-Based Definition (MBD)/(MBDef)

The practice of using 3D models (such as solid models, 3D PMI and associated metadata) within 3D CAD software to define (provide specifications for) individual components and product assemblies. The types of information included are geometric dimensioning and tolerancing (GD&T), component level materials, assembly level bills of material, engineering configurations, design intent, etc.

Derived from Wikipedia

Model Based Definition is a subset of Model Based Design

Model-Based Design (MBD)

The use of models and modeling techniques as an integral part of the design phase of a development process.

SMSWG T-D Committee

Model-Based Design is a subset of Model Based Engineering (MBE)

Model-Based Development (MBDev)

The systematic use of models and modeling techniques as an integral part of the overall development engineering process.


Model-Based Development (MBDev) is a subset of Model Based Engineering (MBE)

Model-Based Engineering (MBE)

An approach to engineering that uses models as an integral part of the engineering processes that includes the requirements, design, analysis, implementation, and the verification and validation of a capability, system, and/or product throughout its life cycle.

Derived from (Final Report, Model-Based Engineering Subcommittee, NDIA, Feb. 2011).

It is the umbrella for many other MBx activities

Model-Based Enterprise (MBE)

An organization where models serve as the authoritative information source for processes beyond engineering.

Derived from Wikipedia

Model Based Enterprise is the culmination of Model Based Engineering

Model-Based Safety Analysis (MBSA)

An approach in which the system and safety engineers share a common system model created using a model-based development process. By extending the system model with a fault model as well as relevant portions of the physical system to be controlled, automated support can be provided for much of the safety analysis.

Model-BaseC1:C16d Safety Analysis, NASA, Feb. 2006

Model Based Safety Analysis is a subset of Model Based Engineering

Model-Based Systems Engineering (MBSE) The formalized application of modeling to support system requirements, design, analysis, verification and validation activities beginning in the conceptual design phase and continuing throughout development and later life cycle phases. INCOSE SE Vision 2020 (INCOSE-TP-2004-004-02, Sep 2007

MBSE is a subset of Model Based Engineering (MBE) and Systems Engineering (SE)

Model in the Loop (MIL)

A simulation approach that abstracts the behaviour of a system or sub-system within a specific model that can be re-used to test, simulate, and verify that system or sub-system within a larger model.


NAFEMS NAFEMS is the International Association of the Engineering Modelling, Analysis and Simulation Community. We are a not-for-profit organization which was established in 1983. They focus on the practical application of numerical engineering simulation techniques such the Finite Element Method for Structural Analysis, Computational Fluid Dynamics, and Multibody Simulation. In addition to end users from all industry sectors, our stakeholders include technology providers, researchers and academics. NAFEMS
Object In HLA, A fundamental element of a conceptual representation for a federate that reflects the "real world"" at levels of abstraction and resolution appropriate for federate interoperability. More generally a representation of a real-world physical item or phenomenon in the synthetic environment." Modeling & Simulation Coordination Office