1) Disassociated from any specific instance of a system or entity 2) All models are an abstraction of reality - the less detail/internal processes being modeled, the more abstract the model is.

The process of selecting the essential aspects of a simulant to be represented in a model or simulation while excluding those aspects that are not relevant to the purpose of the model or simulation. The set of elements produced by this process. Views that highlight some, usually related, details of the problem or solution.

The rate of change of velocity with respect to time; broadly :  change of velocity

Captures credible potential accidents whereby accidents are sequences of one or more events that cause unplanned harm to valuable assets

Harm caused as outcome of an accident.

Classification of an accident.

The official determination that an M&S application and its associated data are acceptable for use for a specific purpose.

The individual, group, or organization designated to conduct an accreditation assessment for a model, simulation, and associated data.

The organization or individual responsible to approve the use of models, simulations, and their associated data for a particular application.

A set of standards that a particular model, simulation, or federation must meet to be accredited for a specific purpose.

The plan documents the requirements for the use of the M&S, generally referred to as M&S requirements. With a clear understanding of the M&S requirements, the acceptability criteria can be defined. The acceptability criteria are the set of standards that an M&S must meet to be accredited for a specific purpose. Additionally, the measures and metrics that will be used to judge whether or not the acceptability criteria have been met, commonly known as measures of effectiveness and measures of performance, are documented in the Accreditation Plan. Together with the common information mentioned above, this information provides the basis for V&V planning to take place.

The difference between a parameter or variable (or a set of parameters or variables) within a model, simulation, or experiment and the true value or the assumed true value.

The stakeholder that acquires or procures a product or service from a supplier.

The process of obtaining a system product or service. (ISO/IEC/IEEE 2015)

Is a multi-functional technical management discipline associated with the design, development, test, production, fielding, sustainment, and improvement modifications of cost effective systems that achieve the user’s peacetime and wartime readiness requirements. (MIL-HDBK-502)

Activity modeling emphasizes the inputs, outputs, sequences, and conditions for coordinating other behaviors. It provides a flexible link to blocks owning those behaviors. The following is a summary of the SysML extensions to UML Activity diagrams.

Represents steps of a process, often making use of "input and output pins" that respectively correspond to the element type required as the input of an activity or action, and the element generated as an output.

A discrete simulation that represents the components of a system as they proceed from activity to activity; for example, a simulation in which a manufactured product moves from station to station in an assembly line.

A computer system capable of autonomous action - of deciding for itself what behaviors are needed to satisfy its design objectives, and capable of interacting with other agents (e.g., a 3D character that exhibits human or human-like behavior).

The coordination of decentralized models that responds autonomously to external stimuli encountered for the purpose of observing and analyzing the emergent behavior and properties of the interactions of a multitude of agents.

A group of entities or a group of other aggregates considered as a single unit. The substitution of the word "unit" is used to avoid phrases like "aggregate ." (IEEE Std 1278.1-2012)

A family of simulation interface protocols and supporting infrastructure software that permit the integration of distinct simulations and war games. Combined, the interface protocols and software enable large-scale, distributed simulations and war games of different domains to interact at the combat object and event level.

Aggregation differs from ordinary composition in that it does not imply ownership. In composition, when the owning object is destroyed, so are the contained objects. In aggregation, this is not necessarily true.

A procedure or a set of well defined steps, rules, or processes used to solve a problem.

Displayed data having jagged edges, as a result of a discrete approach to scan conversion in which each pixel either is replaced with the primitive's color or is left unchanged.

The systematic, thoughtful, and rigorous employment of the scientific method to examine a problem, scenario, or issue in order to gain insights into relationships between constituent components, understand underlying principles, or answer a specific set of pre-identified questions.

Is an analytical comparison of the operational effectiveness, cost, and risks of proposed materiel solutions to gaps and shortfalls in operational capability. AoAs document the rationale for identifying and recommending a preferred solution or solutions to the identified shortfall(s)

A model consisting of a set of mathematical equations; e.g., a system of solvable equations that represents the laws of thermodynamics or fluid mechanics.

(System Architecture) fundamental concepts or properties of a system in its environment embodied in its elements, relationships, and in the principles of its design and evolution

The Architecture Analysis & Design Language (AADL) is a modeling notation with well-defined semantics for representing the architecture of large-scale software-intensive embedded systems and systems of systems, such as aircraft, spacecraft, motorized vehicles, autonomous systems, and medical devices. The Open Source AADL Tool Environment (OSATE) provides a tool platform for AADL.

A visible part of a simulated entity that is able to move relative to the entity relative to other articulated parts. (IEEE Std 1278.1-2012)

The evaluation or estimation of the nature, quality, or ability of someone or something.

1) Captures valuable assets that must be protected from accidental harm. 2) A model of an asset to be protected with emphasis on security aspects.

Classification of levels of harm to an asset.

Classification of an asset.

Value (monetary, operational...) of an asset.

Risk (probability, consequence) associated with the occurrence of a particular event

In UML models, an association is a relationship between two classifiers, such as classes or Use Cases, that describes the reasons for the relationship and the rules that govern the relationship.

A supposition on the current situation or a presupposition on the future course of events, either or both assumed to be true in the absence of positive proof, necessary to enable the commander in the process of planning to complete an estimate of the situation and make a decision on the course of action. (JP 1-02)

A visible part of a simulated entity that may not move relative to the entity, but that may be present. For example, a bomb on an aircraft wing station. (IEEE Std 1278.1-2012)

A model of the attack process/strategy/tactic.

A model of the entity conducting the attack.

A property or characteristic of an entity, object or event (e.g., color, weight, sex, time of occurrence).

The property of an instance attribute that gives another federate the capability to supply values for that instance attribute during simulation execution.

A type of virtual reality in which synthetic stimuli are registered with and superimposed on real world objects; often used to make information otherwise imperceptible to human senses perceptible.

A recognized or official data production source with a designated mission statement, source, or product that publishes reliable and accurate data for subsequent use by customers. An authoritative data source may be the functional combination of multiple separate data sources.

An entity that can operate independently - without input or guidance from another entity - to achieve objectives within a simulated environment.

Reference Architecture for automotive (embedded?) SW

A virtual object used to represent a participant or physical object in a simulation; the (typically visual) representation may take any form.

Searching backwards from the outcome to identify the chain of decision/events that can lead to that outcome.

A specification or product that has been formally reviewed and agreed upon, that thereafter serves as the basis for further development, and that can be changed only through formal change control procedures. (ISO/IEEE 2008)

The physical environment in which the simulated warfare will take place and the forces that will conduct the simulated warfare. All elements that support the front line forces (i.e., logistics, intelligence) are included.

Bayesian analysis is a statistical procedure which endeavors to estimate parameters of an underlying distribution based on the observed distribution.

Is a graphical model that encodes probabilistic relationships among variables of interest.

Bayesian networks (BNs), also known as belief networks (or Bayes nets for short), belong to the family of probabilistic graphical models (GMs). These graphical structures are used to represent knowledge about an uncertain domain. In particular, each node in the graph represents a random variable, while the edges between the nodes represent probabilistic dependencies among the corresponding random variables. These conditional dependencies in the graph are often estimated by using known statistical and computational methods. Hence, BNs combine principles from graph theory, probability theory, computer science, and statistics.

For a given object, how attribute value changes affect or are affected by the attribute value changes of itself, other objects, or the simulation environment.

An arrangement of functions and their sub-functions and interfaces (internal and external) which defines the execution sequencing, conditions for control or data-flow and the performance requirements to satisfy the requirements baseline. (ISO/IEC 2010)

(1) Systems behavior is a change which leads to events in itself or other systems. Thus, action, reaction or response may constitute behavior in some cases. (Ackoff 1971) (2) The effect produced when an instance of a complex system or organism is used in its operational environment. (Created for SEBoK)

Is a description (Figure 3) how the proposed system will interact with the actors and with entitles which is out of boundary of the system.

An accepted representation or standard of a process being modeled or simulated against which the results of other models or simulations are compared or judged. (SISO-REF-002-1999)

The comparison between the output of a model or simulation and the benchmark.

A model whose inputs, outputs, and functional performance are known, but whose internal implementation is unknown or irrelevant. Also see white box model. (IEEE Std 610.3-1989)

Block diagram is a diagram of a system in which the principal parts or functions are represented by blocks connected by lines that show the relationships of the blocks

The values assumed by the variables in a system, model, or simulation when one or more of them is at a limiting value or a value at the edge of the domain of interest. Also see: Final Condition; Initial Condition. (IEEE Std 610.3-1989)

A combination of hardware and software to link two similar networks that use the same protocol.

The activity of making, buying, or selling goods or providing services in exchange for money

1) Realize courses of action. Courses of action are undertaken to ensure that the enterprise makes progress towards one or more of its goals. 2) the series of steps that a business executes to produce a product or service.

BPEL (Business Process Execution Language) is an XML-based language that enables task-sharing in a distributed computing or grid computing environment.

Is the activity of representing processes of an enterprise, so that the current process may be analyzed or improved.

The primary goal of BPMN is to provide a notation that is readily understandable by all business users, from the business analysts that create the initial drafts of the processes, to the technical developers responsible for implementing the technology that will perform those processes, and finally, to the business people who will manage and monitor those processes. Thus, BPMN creates a standardized bridge for the gap between the business process design and process implementation.

The campaign model has been a key tool in such joint force structure analysis, strategy assessment, and operational planning.

(1) The ability to achieve a desired effect under specified (performance) standards and conditions through combinations of ways and means (activities and resources) to perform a set of activities. (DoD 2009) (2) The ability to execute a specified course of action. It is defined by a user and expressed in non-equipment based operational terms. (MOD 2004) (3) The ability to execute a specified course of action. A capability may or may not be accompanied by an intention. (DoD 2009) (4) The ability to perform a function, task, or action. (Created for SEBoK)

Expresses capability requirements.

Is a process improvement approach that provides organizations with the essential elements of effective processes, which will improve their performance.

Describes capability taxonomy and capability evolution.

Is an ‘augmented’ statistical model that incorporate important causal information which contributes to their causal interpretation

A mechanism for manifesting a virtual reality experience that involves placing the participant within a room like space that is surrounded by computer generated imagery.

Cellular automata are used as simple mathematical models to investigate self-organization in statistical mechanics.

A method for numerically integrating second order dynamic equations of motion. It is widely used as a technique for solving non-linear dynamic problems.

Same as the Eigenvalue.

Same as the Eigenvector.

A method of solving a set of simultaneous equations that is especially well suited to the Finite Element method. It is sometimes called a skyline solution. Choose to optimize the profile of the matrix if a renumbering scheme is used.

A description of a group of items with similar properties, common behavior, common relationships, and common semantics.

A class diagram in the Unified Modeling Language (UML) is a type of static structure diagram that describes the structure of a system by showing the system's classes, their attributes, operations (or methods), and the relationships among objects.

A method in which the states or status of resources are described as explicit and computationally tractable functions. (e.g., in a dynamic model, the status of a resource at time "t" can be found by evaluating the appropriate function at "t" without having to simulate combat from the start of that combat through time "t".)

The system parameter relating force to velocity.

A cognitive model is an approximation to animal cognitive processes (predominantly human) for the purposes of comprehension and prediction. Cognitive models can be developed within or without a cognitive architecture, though the two are not always easily distinguishable.

An environment enabling multiple users to interact within a simulation

An exercise in which the forces are simulated, involving the commander, the staff, and communications within and between headquarters. (JP 1-02)

A commercial item sold in substantial quantities in the commercial marketplace and offered to the government under a contract or subcontract at any tier, without modification, in the same form in which it was sold in the marketplace. This definition does not include bulk cargo such as agricultural products or petroleum. (FAR, subpart 2.101)

OMG's open, vendor-independent architecture and infrastructure that computer applications use to work together over networks. Using the standard protocol IIOP, a CORBA-based program from any vendor, on almost any computer, operating system, programming language, and network, can interoperate with a CORBA-based program from the same or another vendor, on almost any other computer, operating system, programming language, and network.

Services, materiel, or facilities provided by a DoD agency or a Military Department on a common basis for two or more DoD agencies, elements, or other organizations as directed. (DoDI 5000.61)

Modeling and Simulation applications, services, or materials provided by a DoD component to two or more DoD components.

A quality that applies to materiel or systems: a. possessing like and interchangeable characteristics enabling each to be utilized, or operated and maintained, by personnel trained on the others without additional specialized training; b. having interchangeable repair parts and/or components; and c. applying to consumable items interchangeably equivalent without adjustment. (JP 1-02)

Compatibility is satisfied if a field variable.

When the functions interpolating the field variable (typically the displacements) form a complete n'th order polynomial in all directions.

System where the individual elements act independently but jointly behave according to common constraints and goals. In the natural world, a flock of geese is a Complex Adaptive System (CAS). Human-intensive systems are also CASs since each human in the system is independent. (Weaver 1948, 536; Jackson, Hitchins, and Eisner 2010, 41; Flood and Carson 1993; Lawson 2010)

Data that cannot be characterized as single concepts including highly derived data; objects utilizing the concepts of multiple inheritance, multiple root hierarchies, and polymorphic attributes; compositions such as command hierarchies, road networks, images, compound documents; and artifacts of legacy systems and physical constraints.

The eigenvectors of a damped system. For proportionally damped systems they are the same as the undamped eigenvectors. For non-proportionally damped systems with damping in all modes less than critical they are complex numbers and occur as complex conjugate pairs.

(1) An entity with discrete structure, such as an assembly or software module, within a system considered at a particular level of analysis. (ISO/IEC 1998) (2) One of the parts that make up a system. (IEEE 2008) (3) A set of functional services in the software, which, when implemented, represents a well-defined set of functions and is distinguishable by a unique name. (ISO/IEC 2008)

The capability to select and assemble reusable Modeling and Simulation components in various combinations into simulation systems to meet user requirements.

A material that is made up of discrete components.

A view of a system from the computational view of a system from the computation independent viewpoint. A CIM does not show details of the structure of systems. A CIM is sometimes called a domain model and a vocabulary that is familiar to the practitioners of the domain in question is used in its specification.

A model consisting of well-defined procedures that can be executed by a computer. (SISO-REF-002-1999)

The use of computer systems to assist in the creation, modification, analysis, or optimization of a design

A command post exercise where computers simulate the operational environment and provide event resolution that may be used in a distributed or non-distributed form or a combination of both.

A computer program which attempts to simulate an abstract model of a particular system.

Numerical control (NC) is the automation of machine tools that are operated by precisely programmed commands encoded on a storage medium, as opposed to controlled manually via hand wheels or levers, or mechanically automated via cams alone. Most NC today is computer numerical control (CNC), in which computers play an integral part of the control.

A simulation that is executed on a computer, with some combination of executing code, control/display interface hardware, and, in some cases, interfaces to real-world equipment.

See: war game

A generic term used to refer to computer representations of forces in models and simulations that attempts to model human behavior sufficiently so that the forces will take some actions automatically (without requiring man-in-the-loop interaction). Types of CGF include: automated forces - computer-generated forces that require little or no human interaction. Semi-automated forces - computer-generated forces in which the individual platform simulation is operated by computer simulation of the platform crew and command hierarchy.

Describes the way the system works from the operator's perspective. It includes the user description and summarizes the needs, goals, and characteristics of the system's user community. This includes operation and maintenance and support personnel.

A model that documents the business information requirements and structural business process rules of the architecture, and describes the information that is associated with the information of the architecture. Included are information items, their attributes or characteristics, and their inter-relationships.

Is an analytical tool with many variations and contexts. It is used to make conceptual distinctions and organize ideas.

The description of what the model or simulation will represent, the assumptions limiting those representations, and other capabilities needed to satisfy the user's requirements. A collection of assumptions, algorithms, relationships, and data that describe a developer's concept about the simulation.

Is a systematic approach to the integrated, concurrent design of products and their related processes, including manufacture and support. This approach is intended to cause the developers, from the outset, to consider all elements of the product life cycle from conception through disposal, including quality, cost, schedule, and user requirements.

The functional and physical characteristics of hardware or software as set forth in technical documentation or achieved in a product (ISO 24765, 2010)

An aggregation of hardware, firmware, computer software, or any of their discrete portions, which satisfies an end-use function and is designated by the government for separate configuration management. Cis may vary widely in complexity, size, and type.

A discipline applying technical and administrative direction and surveillance to: identify and document the functional and physical characteristics of a configuration item, control changes to those characteristics, record and report change processing and implementation status, and verify compliance with specified requirements. (ISO/IEC/IEEE 2010)

A document, typically prepared by the supplying activity, defining in detail how configuration management will be implemented for a particular acquisition or program.

A transformation of the coordinate system of the problem that preserves the symmetry of the system matrices.

A simulation in which events are processed in a manner that never violates the correct chronology.

A parameter, variable or data item within a model or simulation whose value cannot change during the course of the execution.

A simulation where time advances are paced to have a specific relationship to wall clock time; real-time or scaled-real-time simulations (e.g., human-in-the-loop (e.g., training exercises), hardware-in-the-loop (e.g., test and evaluation simulations)). (SISO-REF-002-1999)

An externally imposed limitation on a process, model, or dataset. (e.g., an equation (equality or inequality) that must be satisfied in order for a possible solution to be determined feasible.)

Simulations involving simulated people operating simulated systems. Real people can be allowed to stimulate (make inputs) to such simulations.

A contact problem occurs when two bodies that are originally apart can come together.

Composition that is used to store several instances of the composited data type is referred to as containment.

Is a diagram that defines the boundary between the system, or part of a system, and its environment, showing the entities that interact with it. This diagram is a high level view of a system.

A context model is used to define the enclosing environment of some system under study. In other words, the context is the surrounding element for the system, and a model provides the mathematical interface and a behavioral description of the surrounding environment.

A mathematical or computational model whose output variables change in a continuous manner; that is, state (dependent) variables change in a continuous manner. Contrast with: discrete model

A graphical representation of the variation of a field variable over a surface. A contour line is a line of constant value for the variable. A contour band is an area of a single color for values of the variable within two limit values.

A legal agreement between people, companies, etc.

The process of adjusting the flow of data.

A system used in a flight simulator or training device to provide pilots with realistic flight control forces.

The engineering discipline that applies control theory to design systems with desired behaviors. focus on implementation of control systems mainly derived by mathematical modeling of systems of a diverse range.

For a structural Finite Element to converge as the mesh is refined it must be able to represent a state of constant stress and strain free rigid body movements exactly. There are equivalent requirements for other problem types.

Cost estimation models are mathematical algorithms or parametric equations used to estimate the costs of a product or project. The results of the models are typically necessary to obtain approval to proceed, and are factored into business plans, budgets, and other financial planning and tracking mechanisms.

It is composed of three interrelated and interdependent models: a technical process model, a production operations model, and a financial accounting model. The decomposition of the problem of cost estimation into these three categories helps not only to establish the scope and boundaries of the task, but also to structure the task of model development so that analyses of otherwise bewildering complexity can be handled.

This is a material property defining the minimum energy that a propagating crack must release in order for it to propagate.

The dividing line between under damped and over damped systems where the equation of motion has a damping value that is equal to the critical damping.

Feature of the environment that has been constructed by man. Included are such items as roads, buildings, canals, marker buoys; boundary lines, and, in a broad sense, all names and legends on a map. (SISO-REF-002-1999)

The organization or person that receives a product or service. (ISO/IEC/IEEE 2015)

Statements of fact and assumptions that define the expectations of the system in terms of mission objectives, environment, constraints, and measures of effectiveness and suitability (MOE/MOS).

Same as Complex Eigenvalues.

Same as Complex Eigenvector.

The frequency at which the damped system vibrates naturally when only an initial disturbance is Applied.

Any mechanism that dissipates energy in a vibrating system.

The damping factor is the ratio of the actual damping to the critical damping. It is often specified as a percentage. If the damping factor is less than one then the system can undergo free vibrations. The free vibrations will decay to zero with time. If the damping factor is greater than one then the decay is exponential and no vibrations occur. For most structures the damping factor is very small.

Representation of facts, concepts, or instructions in a formalized manner suitable for communication, interpretation, or processing by humans or by automatic means. Any representations such as characters or analog quantities to which meaning is or might be assigned.

Any entity that is comprised of data. For example, a database is a data asset that is comprised of data records. A data asset may be a system or application output file, database, document, or web page. A data asset also includes a service that may be provided to access data from an application. For example, a service that returns individual records from a database would be a data asset. Similarly, a web site that returns data in response to specific queries (e.g., www.weather.com) would be a data asset. A human, system, or application may create a data asset. (DoDD 8320.02)

The determination that data have been verified and validated. Data user certification is the determination by the application sponsor or designated agent that data have been verified and validated as appropriate for the specific Modeling and Simulation usage. Data producer certification is the determination by the data producer that data have been verified and validated against documented standards or criteria. (IEEE Std 1278.3-1996)

A specialized type of database containing metadata that is managed by a data dictionary system. A repository of information describing the characteristics of data used to design, monitor, document, protect, and control data in information systems and databases.

The Data Distribution Service for Real-Time Systems (DDS) is an Object Management Group (OMG) machine to machine middleware "m2m" standard that aims to enable scalable, real-time, dependable, high performance and interoperable data exchanges between publishers and subscribers.

An atomic unit of data that has precise meaning or precise semantics.

1) The flow of data between entities in a system (and across the system boundary). 2) The process of identifying, modeling and documenting how data moves around an information system.

A device that accepts data outputs from a simulation or federation and stores them for processing and replay.

Determines the logical structure of a elements and fundamentally determines in which manner data can be stored, organized, and manipulated.

The process of verifying the internal consistency and correctness of data and validating that it represents real-world entities appropriate for its intended purpose or an expected range of purposes. (DoDI 5000.61)

A usually large collection of data organized especially for rapid search and retrieval (as by a computer)

A method for the estimation of the position/orientation of an entity based on a previously known position/orientation and estimates of the passage of simulation time and motion. (IEEE Std 1278.1-2012)

A node in a decision tree with two or more outcomes.

The outcome of a decision over time.

A decision gate is an approval event (often associated with a review meeting). Entry and exit criteria are established for each decision gate; continuation beyond the decision gate is contingent on the agreement of decision-makers.

Model containing a cohesive set of interrelated decisions and their consequences.

Decision tables, like flowcharts and if-then-else and switch-case statements, associate conditions with actions to perform, but in many cases do so in a more elegant way.

A decision tree is a decision support tool that uses a tree-like graph or model of decisions and their possible consequences, including chance event outcomes, resource costs, and utility.

An explanation of the meaning of a word, phrase, etc. : a statement that defines a word, phrase, etc.

A scenario where a degraded system/component is modeled (reduced capabilities and/or characteristics).

The number of degrees of freedom for a system is equal to the number of coordinates which are used to specify the configuration of a system minus the number of constraints. In rigid body motion with no constraints, there are 6 degrees of freedom: translation along X, translation along Y, translation along Z; rotation around X, rotation around Y, rotation around Z.

"The number of equations of equilibrium for the system. In dynamics

A variable whose value is a function of one or more independent variables. Contrast with: independent variable (SISO-REF-002-1999)

Constraint stated during the design activities which arise as a result of the selected solution (for example, a necessary mean or resource related to a technology, or an interface between two components of different sub-systems). (Faisandier 2012)

Purpose, planning, or intention that exists or is thought to exist behind an action, fact, or material object.

Inherent limitations on the sizing and capabilities of the system, its interfacing systems, and its operational and physical environment.

The design model is an object model describing the realization of Use Cases, and serves as an abstraction of the implementation model. The design model is used as essential input to activities in implementation and test.

A model in which the results are determined through known relationships among the states and events and in which a given input will always produce the same output; for example, a model depicting a known chemical reaction. Contrast with: Stochastic Model. (SISO-REF-020-2007)

A graphic design that explains rather than represents; especially : a drawing that shows arrangement and relations (as of parts)

A numerical model of the elevations of points on the earth's surface. Digital records of terrain elevations for ground positions at regularly spaced horizontal intervals.

A database of selected natural and manmade planimetric features classified as point, line, or area features as a function of their size and composition.

Digital data of all natural feature, man's alteration to those features, and the measurement and description of physical features of the oceans, lakes, rivers and other waters and their adjoining coastal areas.

A simulation that is designed to be executed on a digital system. (IEEE Std 610.3-1989)

A digital representation of a defense system, generated by all stakeholders that integrates the authoritative technical data and associated artifacts which define all aspects of the system for the specific activities throughout the system lifecycle.

A uniform matrix of terrain elevation values which provides basic quantitative data for all military systems that require terrain elevation, slope, and/or surface roughness information.

An extensible, configurable and component enterprise-level analytical framework that seamlessly expedites the controlled interplay of authoritative technical data, software, information, and knowledge in the enterprise data-information-knowledge systems, based on the Digital System Model template, to inform decision makers throughout a system's life cycle by providing the capability to access, integrate and transform disparate data into actionable information.

An integrated multiphysics, multiscale, probabilistic simulation of an as-built system, enabled by Digital Thread, that uses the best available models, sensor information, and input data to mirror and predict activities/performance over the life of its corresponding physical twin.

Is a directed graph with no directed cycles.

Is a set of vertices and a collection of directed edges that each connects an ordered pair of vertices. We say that a directed edge points from the first vertex in the pair and points to the second vertex in the pair. We use the names 0 through V-1 for the vertices in a V-vertex graph.

The process of replacing a single aggregate with two or more aggregates or entities at a higher level of detail.

To establish a single semantic or grammatical interpretation for

A type of metadata that describes or summarizes key attributes and concepts, and allows assets (e.g., a model, simulation, or data) to be found using enterprise-level search capabilities. (DoDI 5000.70)

A discrete-event simulation (DES), models the operation of a system as a discrete sequence of events in time. Each event occurs at a particular instant in time and marks a change of state in the system. Between consecutive events, no change in the system is assumed to occur; thus the simulation can directly jump in time from one event to the next.

A simulation where the dependent variables (i.e., state indicators) change at discrete points in time referred to as events.

A modeling formalism, methodology and specification framework that provides a theoretical foundation independent of programming languages and hardware platforms.

A mathematical or computational model whose output variables take on only discrete values; that is, in changing from one value to another, they do not take on the intermediate values. Contrast with: continuous model. (SISO-REF-020-2007)

An exercise enabled by distributed simulation where the training participants are at different locations (i.e., different cities, countries or continents).

A time and space coherent synthetic representation of world environments designed for linking the interactive, free-play activities of people in operational exercises. The synthetic environment is created through real-time exchange of data units between distributed, computationally autonomous simulation applications in the form of simulations, simulators, and instrumented equipment interconnected through standard computer communicative services. The computational simulation entities may be present in one location or may be distributed geographically. (IEEE Std 1278.1-2012)

A simulation that has multiple modules, which can be run on multiple processors. The processors can be co-located in the same room or located in remote sites.

A seven-step process used to develop and execute distributed simulation events as standardized in IEEE Std 1730-2010.

A DoD activity area, enabled by Modeling and Simulation, that has an established executive-level management structure. Examples of such activities that meet these criteria include acquisition, training, and analysis. (DoDD 5000.59)

A high-level DoD plan created and published by a DoD Community to facilitate and achieve the DoD Modeling and Simulation Strategic Vision, goals, and objectives for that DoD Community. (DoDI 5000.70)

Models and simulations designated by a Community to focus Community management of Modeling and Simulation and to limit the scope of the Components' responsibility to develop, manage, and provide Component data, and support the development of tools and services. (DoDD 5000.59)

An enterprise-level capability that enables the discovery of metadata about Modeling and Simulation assets to facilitate visibility into the resources available across the DoD and within other Federal and non-Federal agencies engaged in Modeling and Simulation, and federated with DoD Modeling and Simulation. Sources of the Modeling and Simulation assets described by the discovery metadata are maintained by DoD Components and other authoritative data and software repositories. Visibility into the discovery metadata enables a user or developer of Modeling and Simulation assets to identify potential reuse opportunities relative to their requirements. (DoDI 5000.70)

Architecture Framework created and mandated by the US Department of Defense

Is a conceptual model capturing the topics related to a specific problem domain.

An analysis that includes the effect of the variables changing with time as well as space.

The factor relating the steady state displacement response of a system to a sinusoidal force input. It is the same as the receptance.

A model of a system in which there is change, such as the occurrence of events over time or the movement of objects through space; for example, a model of a bridge that is subjected to a moving load to determine characteristics of the bridge under changing stress. (SISO-REF-020-2007)

A modeling process where consideration as to time effects in addition to spatial effects are included. A dynamic model can be the same as a static model or it can differ significantly depending upon the nature of the problem.

An environment that can be constantly changing as a result of man-made activities (battlefield smoke) and natural phenomena (weather).

If the structure is vibrating steadily at a frequency w then the dynamic stiffness is (K+iwC-w2M) It is the inverse of the dynamic flexibility matrix.

Stresses that vary with time and space.

Special forms of substructuring used within a dynamic analysis. Dynamic substructuring is always approximate and causes some loss of accuracy in the dynamic solution.

The dynamical system concept is a mathematical formalization for any fixed "rule" which describes the time dependence of a point's position in its ambient space. The concept unifies very different types of such "rules" in mathematics: the different choices made for how time is measured and the special properties of the ambient space may give an idea of the vastness of the class of objects described by this concept. Time can be measured by integers, by real or complex numbers or can be a more general algebraic object, losing the memory of its physical origin, and the ambient space may be simply a set, without the need of a smooth space-time structure defined on it.

is a simplified description of reality, designed to yield hypotheses about economic behavior that can be tested.

A change that results when something is done or happens : an event, condition, or state of affairs that is produced by a cause

If the relationship between loads and displacements is linear then the problem is elastic. For a multi-degree of freedom system the forces and displacements are related by the elastic stiffness matrix.

Electro-magnetic and electro-static problems form electric field problems.

In the Finite Element method the geometry is divided up into elements. Each element has nodes associated with it. The behavior of the element is defined in terms of the freedoms at the nodes.

Individual element matrices have to be assembled into the complete stiffness matrix. This is basically a process of summing the element matrices. This summation has to be of the correct form. For the stiffness method the summation is based upon the fact that element displacements at common nodes must be the same.

A behavior or property that appears when a number of simple entities (agents) operate in an environment, forming more complex behaviors as a collective.

A device, computer program, or system that performs emulation. (SISO-REF-002-1999)

A system that complements a system-of-interest during its life cycle stages, but does not necessarily contribute directly to its function during its operation stage. (INCOSE 2012)

The engagement level spans the application domains of missile defense as well as air, surface, strike, and undersea warfare.

1)     The activities or function of an engineer 2a) The application of science and mathematics by which the properties of matter and the sources of energy in nature are made useful to people 2b) The design and manufacture of complex products 3) Calculated manipulation or direction (as of behavior)

A specific type of prototype models represents a near complete design that is used during the Engineering and Manufacturing Development (EMD) Phase that is built from approved Critical Design Review (CDR) drawings.

Each eigenvector (mode shape or normal mode) can be multiplied by an arbitrary constant and still satisfy the eigenvalue equation. Various methods of scaling the eigenvector are used Engineering normalization - The vector is scaled so that the largest absolute value of any term in the eigenvector is unity. This is useful for inspecting printed tables of eigenvectors. Mathematical normalization - The vector is scaled so that the diagonal modal mass matrix is the unit matrix. The diagonal modal stiffness matrix is the system eigenvalues. This is useful for response calculations.

An arbitrarily defined functional and administrative entity that exists to perform a specific, integrated set of missions and achieve associated goals and objectives, encompassing all of the primary functions necessary to perform those missions. (DoDI 5000.70)

Information model(s) that presents an integrated top-level representation of processes, information flows, and data.

A distinguishable person, place, unit, thing, event, or concept about which information is kept. (SISO-REF-020-2007)

The perception of the synthetic environment held by a simulation entity based on its knowledge of itself and its interactions with the other simulation entities. This includes not only its own view of the simulated physical environment, but also its own view of itself, the other entities in the synthetic environment, and of the effects of the other entities on itself and the synthetic environment. Syn: World View. (SISO-REF-020-2007)

Represent database models and information systems. The main components of the diagram are the entities and relationships. The entities can represent independent functions, objects, or events. The relationships are responsible for relating the entities to one another

1) Anything affecting a subject system or affected by a subject system through interactions with it, or anything sharing an interpretation of interactions with a subject system. (IEEE 1175.1-2002 (R2007), 3.6) 2) The surroundings (natural or man?made) in which the system?of-interest is utilized and supported; or in which the system is being developed, produced or retired. (INCOSE 2010)

An individual element of the physical environment.

Models that represent the environment the system will operate in

A model, simulation, or database designed to produce an accurate and consistent data set for one or more parameters that characterize the state of the physical environment.

A statement that the values of two mathematical expressions are equal (indicated by the sign =).

Internal forces and external forces must balance. At the infinitesimal level the stresses and the body forces must balance. The equations of equilibrium define these force balance conditions.

Most of the current Finite Elements used for structural analysis are defined by assuming displacement variations over the element. An alternative approach assumes the stress variation over the element. This leads to equilibrium Finite Elements.

The necessary items for a particular purpose.

"A three dimensional solid has six stress components. If material properties have been found experimentally by a uniaxial stress test then the real stress system is related to this by combining the six stress components to a single equivalent stress. There are various forms of equivalent stress for different situations. Common ones are Tresca

A model used to estimate or predict the extent of deviation of the behavior of an actual system from the desired behavior of the system. (SISO-REF-020-2007)

An event in the Unified Modeling Language (UML) is a notable occurrence at a particular point in time.

A change of object attribute value, an interaction between objects, an instantiation of a new object, or a deletion of an existing object that is associated with a particular point on the federation time axis. Each event contains a time stamp indicating when it is said to occur.

The reason the event occurred - the event trigger

The outcome of an event (over time)

Consists of entities/elements and functions that allow relationships to be developed and processed. More specifically, the EPC is made up of events which define what state a process is in or the rules by which it operates. In order to progress through events, a function/ active event must be executed. Depending on the process flow, the function has the ability to transform event states or link to other event driven process chains

An ordered list that contains the time all events will occur.

Contains a cohesive set of events, their causes, and/or their consequences

The likelihood of an event occurring

A simulation in which attention is focused on the occurrence of events and the times at which those events occur. (IEEE 610.3-1989)

N/A

Solutions that satisfy the differential equations and the associated boundary conditions exactly. There are very few such solutions and they are for relatively simple geometries and loadings.

A model that instantiates the conceptual model of a system as its design specification.

A military maneuver or simulated wartime operation normally involving planning, preparation, execution, and after-action review. Also see simulation exercise.

A belief that something will or should occur.

A process using simulation to identify, develop, assess and recommend changes to doctrine, organizational structure, training, material, leadership and education, people, and facilities required to achieve advances in operational capabilities.

A knowledge collection combined with an inference engine capable of interpreting queries and chaining together separate items of knowledge to develop new inferences.

These are methods for integrating equations of motion. Explicit methods can deal with highly non-linear systems but need small steps. Implicit methods can deal with mildly non-linear problems but with large steps.

In UML modeling, you can use an extend relationship to specify that one Use Case (extension) extends the behavior of another Use Case (base). This type of relationship reveals details about a system or application that are typically hidden in a Use Case.

The ability of a model, simulation, or data structure to accommodate additional values or iterations of data over time without impacting the initial design.

How the system is required to interact or to exchange material, energy, or information with external systems.

Interfaces a system offers to external entities (other systems or human users)

The process of estimating a value of a variable from a tabulated set of values. For interpolation values inside the table are estimated. For extrapolation values outside the table are estimated. Interpolation is generally accurate and extrapolation is only accurate for values slightly outside the table. It becomes very inaccurate for other cases.

The process of determining whether a model or simulation seems reasonable to people who are knowledgeable about the system under study, based on the model's performance. This process does not review the software code or logic, but rather reviews the inputs and outputs to ensure they appear realistic or representative. (SISO-REF-020-2007)

Something (such as a building or large piece of equipment) that is built for a specific purpose

(1) Termination of the ability of a product to perform a required function or its inability to perform within previously specified limits. (ISO/IEC 2005, 4.2) (2) An event in which a system or system component does not perform a required function within specified limits. (ISO/IEC/IEEE 2009, 1) (3) The event in which any part of an item does not perform as required by its specification. The failure may occur at a value in excess of the minimum required in the specification, i.e., past design limits or beyond the margin of safety. (INCOSE 2012)

A condition when the differences between the performance characteristics of two or more interoperating simulations have significantly less effect on the outcome of a simulated situation than the actions taken by or resources available to the simulation participants. (SISO-REF-020-2007)

Are analyzable approximations of defects and are essential for a test methodology.

Allows for a top down, deductive failure analysis in which an undesired state of a system is analyzed using Boolean logic to combine a series of lower-level events.

An element of the synthetic environment that does not actively participate in interactions. Features are passive and do not initiate action.

In HLA, an application that may be or is currently coupled with other software applications under a Federation Object Model (FOM) Document Data (FDD) and a runtime infrastructure (RTI). (IEEE Std 1516.2-2010)

The ability to search across multiple archives, data collections, or multiple content aggregator services. (DoDI 5000.70)

In HLA, a named set of federate applications and a common federation object model (FOM) that are used as a whole to achieve some specific objective. (IEEE Std 1516-2000) More generally, a system of interacting models, simulations, and a supporting infrastructure that are based on a common understanding of the objects portrayed in the system.

A seven-step process used to develop and execute High Level Architecture (HLA) federations as standardized in IEEE Std 1516.3-2003. This standard has been superseded by the Distributed Simulation Engineering and Execution Process.

A system of interacting models, simulations, and supporting infrastructure that are based on a common understanding of the objects portrayed in the system. (MIL-STD-3022)

The degree to which a model or simulation represents the state and behavior of a real world object or the perception of a real world object, feature, condition, or chosen standard in a measurable or perceivable manner; a measure of the realism of a model or simulation.

The angular extent of the observable world that is seen at any given moment. (DoD Modeling and Simulation Human Capital Strategy)

The values assumed by the variables in a system, model, or simulation at the completion of some specified duration of time; final state. (IEEE Std 610.3-1989)

A numerical method for solving partial differential equations by expressing them in a difference form rather than an integral form. Finite difference methods are very similar to Finite Element methods and in some cases are identical.

An approximate method for calculating the behavior of a real structure. An idealized model structure is created by subdividing the geometry of a structure into elements which are connected at nodes. The method is based on the generalized method of weighted residuals using locally-based approximations.

The quality of a model or simulation to provide the capabilities, correctness, accuracy, and usability needed for the intended use or current application.

The dynamic motion results from a time varying forcing function.

The dynamic forces that are Applied to the system.

A declaration that something will happen in the future

Searching forwards from events to identify possible outcomes

The rate at which a complete image is displayed on a display device.

A basic structure underlying a system, concept, or text.

The dynamic motion which results from specified initial conditions. The forcing function is zero.

The structures forcing function and the consequent response is defined in terms of their frequency content. The inverse Fourier transform of the frequency domain gives the corresponding quantity in the time domain.

A function is interpreted as a specific process, action or task that a system is able to perform

A multi-tier, time-sequenced, step-by-step flow diagram of a system's functional flow.

Set of functions and their sub-functions that defines the transformations of input flows into output flows performed by the system to achieve its mission.

Is a top-down process of translating system level requirements into detailed functional and performance design criteria.

Functional mock-up interface (or FMI) defines a standardized interface to be used in computer simulations to develop complex cyber physical systems

The instantiation, initialization and/or execution of an individual executable (or C code) model representation performed within a simulation environment. The FMU contains a concrete mathematical model described by differential, algebraic and discrete equations with possible events of a dynamic physical system transformed into explicit form and represented as C code or machine code.

A systematic way to describe a what a system does.

Specify what the system should be able to do when fielded and operated in its intended operating environment.

The study of situations involving competing interests, modeled in terms of the strategies, probabilities, actions, gains, and losses of opposing players in a game. (IEEE Std 610.3-1989)

A device that connects two or more systems, especially if the systems use different protocols. For example, a gateway might be needed to connect two independent local networks, or to connect a local network to a long-haul network.

Specific representations used by, or common to, many models and simulations (e.g., physical environment or environmental effects such as terrain, atmospheric, or hydrographic effects). (DoDI 5000.61)

is a binary taxonomic (i.e. related to classification) directed relationship between a more general classifier (superclass) and a more specific classifier (subclass).

Is an umbrella converging many standard FEMs.

Stochastic algorithms whose search methods model some natural phenomena.

A branch of Applied mathematics and computational geometry that studies methods and algorithms for the mathematical description of shapes

An interface grammar for a component specifies the sequences of method invocations that are allowed by that component

1) The collection of all points whose coordinates satisfy a given relation (as a function) 2) A diagram (as a series of one or more points, lines, line segments, curves, or areas) that represents the variation of a variable in comparison with that of one or more other variables

A symbolic model whose properties are expressed in diagrams. (e.g., a decision tree used to express a complex procedure.) (SISO-REF-020-2007)

Deformations sufficiently high to make it necessary to include their effect in the solution process. The problem requires a large deflection non-linear analysis.

The actual facts of a situation, without errors introduced by sensors or human perception and judgment. (SISO-REF-020-2007)

Are Boolean expressions evaluated dynamically based on the value of extended state variables and event parameters. Guard conditions affect the behavior of a state machine by enabling actions or transitions only when they evaluate to TRUE and disabling them when they evaluate to FALSE. In the UML notation, guard conditions are shown in square brackets.

Forces arising from Coriolis acceleration. These can destabilize a dynamic response and cause whirling.

Refers to all the physical sensors that provide a sense of touch at the skin level and force feedback information from muscles and joints.

Simulation and simulators that employ one or more pieces of operational equipment (to include computer hardware) within the simulation/simulator system. (DoD Modeling and Simulation Human Capital Strategy)

Models representing hardware capabilities and characteristics to support engineering activities

A type of dynamic simulation that includes one or more actual system components operating in conjunction with simulated components.

A dynamic loading that is periodic and can be represented by a Fourier series.

Cause of a situation that poses a level of threat to life, health, property, or environment.

Consequence of a situation that poses a level of threat to life, health, property, or environment.

A statistical technique for determining 'hazard functions', or the probability that an individual will experience an event (for example first employment) within a particular time-period, given that the individual was subject to the risk that the event might occur (in this case, given continuing initial unemployment).

Captures credible potential Hazards whereby hazards are collection of conditions in the system and its environment that are prerequisites to the occurrence of accidents.

a measure or estimate of the degree of confidence one may have in the occurrence of an event, measured on a scale from zero (impossibility) to one (certainty). It may be defined as the proportion of favorable outcomes to the total number of possibilities if these are indifferent (mathematical probability), or the proportion observed in a sample (empirical probability), or the limit of this as the sample size tends to infinity (relative frequency), or by more subjective criteria (subjective probability)

A source of danger.

The analysis of the steady state heat flow within solids and fluids. The equilibrium balance between internal and external heat flows.

A model in which superior/subordinate relationships are represented, often as trees of records connected by pointers.

Is a ranking or ordering of abstractions.

A family of related standards that describe a unified approach and common architecture used to construct interoperable simulation systems as standardized in IEEE 1516.

Is a family of related standards that together describe a unified approach and common architecture to constructing interoperable simulation systems. It contains major functional elements, interfaces, and design rules, pertaining to all DoD simulation applications, and providing a common framework within which specific system architectures can be defined.

The material property equations relating stress to strain for linear elasticity. They involve the material properties of Youngs modulus and Poisson ratio.

The classical cognitive functions, as well as the effects of moderators such as stress, injury, fatigue, discomfort, motivation, and emotions. Any form of human representation, including individuals, aggregates of individuals and organizations.

A representation of the action of a single human or the collective action of a team of humans. Human behavior representation models the aspects of the complicated facets of human behavior including ability to reason, ability to change the environment, reaction to comfort or discomfort, susceptibility to injury and illness, emotional response, communication with others, ability to sense the environment and physical capabilities and limitations.

Model of a human activity in which individual or group behaviors are derived from the psychological or social aspects of humans. Behavioral models include a diversity of approaches; however, computational approaches to human behavior modeling that are most prevalent are social network models and multi-agent systems.

The study of man-machine relationships and interactions. The term covers all biomedical and psychological considerations; it includes, but is not limited to, principles and applications in the areas of human engineering, personnel selection, training, life support, job performance aids, and human performance evaluation.

Is a model type that requires human interaction during runtime. It employs one or more human operators in direct control of the simulation/simulator or in some key support function.

Human systems interface (HSI) technologies leverage and extend the capabilities of warfighters and maintainers to ensure that fielded systems will exploit the fullest potential of the warfighting team.

The interdisciplinary technical and management processes for integrating human considerations within and across all system elements; an essential enabler to systems engineering practice. (ISO/IEC/IEEE 2011)

A model of the structure, interconnections, dependencies, behavior, and trends associated with any collection of individuals ranging from the small unit level (e.g., tribes, militias, small military units, terrorist cells) to the macro level (e.g., of nations, religions, cultures, ethnic groups and international organizations), and the integrated relationships between and among them.

Simulation and simulators that employ one or more human operators in direct control of the simulation/simulator or in some key support function. (DoD Modeling and Simulation Human Capital Strategy)

The stress arising from a uniform pressure load on a cube of material. It is the average value of the direct stress components at any point in the body.

A damping model representing internal material loss damping. The energy loss per unit cycle is independent of frequency. It is only valid for harmonic response.

Informal name for (a subset of) non-functional requirements

The placing of a human in a synthetic environment through physical and/or emotional means.

Simulation that deeply involves one's senses.

The means by which a model or simulation or portions of a model or simulation is realized. (SISO-REF-020-2007)

A specification, which provides all the information needed to construct a system and to put it into operation

The International Council on Systems Engineering (INCOSE) is a not-for-profit membership organization founded to develop and disseminate the interdisciplinary principles and practices that enable the realization of successful systems. Their mission is to share, promote and advance the best of systems engineering from across the globe for the benefit of humanity and the planet. Their vision is to be the world's authority on Systems Engineering.

A variable whose value is not dependent on the values of other variables. Contrast with: dependent variable. (IEEE 610.3-1989)

The conduct of verification and validation of a model, simulation, and associated data by an individual, group, or organization that did not participate in the development and is not in the same chain of command or organization as the developer.

A model that represents the processes, entities, information flows, and elements of an organization and all relationships between these factors.

The values assumed by the variables in a component, system, model, or simulation at the beginning of some specified duration of time; initial state. (SISO-REF-002-1999)

Value at time zero

The externally supplied data to which a simulation responds and from which it calculates its output (e.g., operator controls, weapon detonation, wind speed, and direction). (SISO-REF-002-1999)

A requirement from one process that goes into another process or a requirement that identifies inputs into a system.

The creation of an object instance of a class.

A simulation that provides stimuli in the synthetic environment for the purpose of training.

An event-based, top level plan consisting of a hierarchy or Program Events. Each event is decomposed into specific accomplishments and each specific accomplishment is decomposed into specific criteria.

A process that combines system elements to form complete or partial system configurations in order to create a product specified in the system requirements. (ISO/IEEE 2008)

Process control diagrams that show the relationship between functions by sequential input and output flows. Process controls enter the top of each represented function, and lines entering the bottom show the supporting mechanism needed by the function.

Intangible property that is the result of creativity, such as patents, trademarks, or copyrights. (DoDI 5000.70)

See: agent

Is a language for specifying operations (procedures or functions), parameters to these operations, and data types. This chapter specifies IDL and the associated Attribute Configuration Source (ACS).

Supporting a plan for system integration and verification strategy

A point where two systems, subjects, organizations, etc., meet and interact.

How system elements within the system, including human elements, interact with each other.

The ability of a model or simulation to provide services to and accept services from other models and simulations, and to use these exchanged services to operate effectively together. (SISO-REF-002-1999)

Cross-domain interoperability refers to the ability of systems and organizations to interact and exchange information (inter-operate) among different areas, markets, industries, countries or communities of interest (domains). When cross-domain interoperability exists, it means that users can seamlessly communicate and conduct activity, despite their reliance on different technical environments or frameworks.

The interconnections between components. Joints can be difficult to model in Finite Element terms but they can significantly effect dynamic behavior.

An Modeling and Simulation tool, data set, or service, including models, simulations, or data assets, that either exceeds $5M in annual expenditures, or is less than $5M but determined by the DoD Component to be "key." The total annual expenditure will be determined using standard justification documentation for DoD appropriations, such as RDT&E (R-docs), Procurement (P-docs), and O&M (O&M exhibits), which are provided to Congress pursuant to DoD 7000.14-R (DoDI 5000.70)

The necessary displacement boundary conditions for a structural analysis. These are the essential boundary conditions in a Finite Element analysis.

A method for finding equivalent nodal loads when the actual load is distributed over a surface of a volume. The element shape functions are used so that the virtual work done by the equivalent loads is equal to the virtual work done by the real loads over the same virtual displacements. This gives the most accurate load representation for the Finite Element model. These are the non-essential stress boundary conditions in a Finite Element analysis.