Taxonomy of Modeling and Simulation

Some Taxonomies of Model Types

Taxonomy I

• Constructive
• Virtual
• Live

Defense Modeling and Simulation Organization
http://www.dmso.mil

Taxonomy II

• Conceptual
• Declarative
• Functional
• Constraint
• Spatial

P. Fishwick, Simulation Model Design and Execution: Building Digital Worlds, 1995

• Live simulation: a simulation involving real people operating real systems
• Virtual simulation: a simulation involving real people operating simulated systems
• Constructive simulation: a simulation involving simulated people operating simulated systems

See https://learn.dau.mil/html/clc/Clc.jsp , CLE023

Taxonomy II

• Conceptual: defines a system at a very high level of abstraction
• Declarative: defines a system as a collection of states and their subsequent changes
• Functional: defines a system in terms of its functions and ways in which outputs are generated for some given input stimuli
• Constraint: defines a system as a set of states and their relationships in a constraint network
• Spatial: defines a system in terms of its geometry
  
• Multi-modeling: models that are composed of other models

Taxonomy II

• Conceptual
• Declarative
• Functional
• Constraint
• Spatial

Taxonomy III

• Source
• Data
• Generative
• Structure

G. Klir, 1985, Architecture of Systems Problem Solving, 1985

Taxonomy IV

• Observation
• I/O relation
• I/O function
• I/O system
• Coupled system

I/O: input/output

B. Zeigler, H. Praehofer, T. Kim, 2000 (ref. Textbook)

Taxonomy III

• Source System: what variables to measure and how to observe them
• Data: data collected from a source system
• Generative: means to generate data in a data system
• Structure: components (at lower level) connected together to form a generative system

Taxonomy IV

• I/O observation: inputs and outputs are observed over some period of time (trajectories)
• I/O relation: pairs of inputs and outputs matched one-to-one over some period of time
• I/O function: Each pair of input/output has an associated initial state
• I/O system: output trajectories are determined based on states alone or states and input trajectories.
  
• Coupled system: output trajectories are generated from interacting I/O systems and lower level coupled systems.
  

Simulation Based Acquisition

The High Level Architecture

Architecture calls for a federation of simulations (federates)

• High Level Architecture (HLA) specifies

• Ten Rules which define relationships among federation components

• An Object Model Template (OMT) which specifies the form in which simulation elements are described

• FOM – federation object model

• SOM – simulation object model

• An Interface Specification (IF) which describes the way simulations interact during operation

** RTI must support the Rules, OMT and IF specifications

M&S Interoperability, Composability & Performance

• Fundamental Premise
• Modeling & Simulation are two distinct, yet complementary, activities. They provide the basis for building distributed simulation models.

• Performance:

• computation
• local to each simulation
• communication
• among multiple simulations
• both computational and communication efficiency issues underlie performance

• Interoperability:
• generic dynamic computer-based and non-computer-based systems
• support a wide range of models and simulations
• hierarchical construction
• Well-defined functionality & interfacing
• Real-time interoperability
• Support design, testing and operational needs

• Composability:
• synthesis of a collection of existing or new sub-systems in such a way that the resultant system behavior is the aggregation of sub-behaviors
• support a wide range of models and simulations
• Reuse
• model and simulation reuse
• centralized and distributed data and model repositories