Live, virtual, and constructive
The dictionary terms used above provide a solid foundation of understanding of the fundamental structure of the LVC topic as applied universally to DoD activities.
Using the medical field as an example, the Live Environment can be a doctor performing CPR on a human patient in a critical real world situation.
Although there are clearly secondary and tertiary training benefits, it is important to understand combining one or more environments for the purpose of making Live real world performance better is the sole reason the LVC concept was created.
However, when referring to specific activities or programs designed to integrate the environments across the enterprise, the use and application of terms differ widely across the DoD.
This is best described by backing away from technical terminology and thinking about how human beings actually prepare for their specific combat responsibilities.
In practice, human beings prepare for their roles in one of three Constructs: Live (with actual combat tools), in a Simulator of some kind, or in other Ancillary ways (tests, academics, computer-based training, etc.).
Operational system examples could consist of a tank, a naval vessel, an aircraft or eventually even a deployed surgical hospital.
For example, a Simulator Construct VC event should be called something other than LVC (such as Distributed Mission Operations (DMO)).
To ensure clarity of discussions and eliminate misunderstanding, when speaking in the LVC context, only the terms in this document should be used to describe the environments, constructs, and components.
154–155, October 11, 1990) Consistent with this direction, the Defense Modeling and Simulation Office (DMSO) was created, and shortly afterwards many DoD Components designated organizations and/or points of contact to facilitate coordination of M&S activities within and across their communities.
A robust M&S capability enables the DOD to meet operational and support objectives effectively across the diverse activities of the military services, combatant commands and agencies.
In the mid 1980s, SIMNET became the first successful implementation of a large-scale, real-time, man-in-the-loop simulator networking for team training and mission rehearsal in military operations.
The earliest successes that came through the SIMNET program was the demonstration that geographically dispersed simulation systems could support distributed training by interacting with each other across network connections.
The ALSP has supported an evolving “confederation of models” since 1992, consisting of a collection of infrastructure software and protocols for both inter-model communication through a common interface and time advance using a conservative Chandy-Misra-based algorithm.
DIS allowed an increased number of simulation types to interact in distributed events, but was primarily focused on the platform-level training community.
[10] In the mid 1990s, the Defense Modeling and Simulation Office (DMSO) sponsored the High Level Architecture (HLA) initiative.
The DoD test community started development of alternate architectures based on their perception that HLA yielded unacceptable performance and included reliability limitations.
[11][12][13] Similarly, the U.S. Army started the development of the Common Training Instrumentation Architecture (CTIA) to link a large number of live assets requiring a relatively narrowly bounded set of data for purposes of providing After Action Reviews (AARs) on Army training ranges in the support of large-scale exercises.
[14] Other efforts that make the LVC architecture space more complex include universal interchangeability software packages such as OSAMS[15] or CONDOR[16] developed and distributed by commercial vendors.
These additional steps, typically involving interposing gateways or bridges between the various architectures, may introduce increased risk, complexity, cost, level of effort, and preparation time.
The limited inherent interoperability between the different protocols introduces a significant and unnecessary barrier to the integration of live, virtual, and constructive simulations.
Other types of problems arise from the general failure to provide a framework which achieves a more complete semantic-level interoperability between disparate systems.
The Study on the Effectiveness of Modeling and Simulation in the Weapon System Acquisition Process[18] identified cultural and managerial challenges as well.
A LVC-IA is also considered an Ultra Large Scale (ULS) system due to the use by a wide variety of stakeholders with conflicting needs and the continuously evolving construction from heterogeneous parts.
Architectural and structural complexity are an area of research in systems theory to measure the cohesion and coupling and is based on the metrics commonly used in software development projects.
Zeigler, Kim, and Praehofer present a theory of modeling and simulation which provides a conceptual framework and an associated computational approach to methodological problems in M&S.
This includes both identifying gaps in M&S capabilities that are common across the enterprise and providing seed moneys to fund projects that have widely applicable payoffs, and conducting M&S investment across the Department in ways that are systematic and transparent.
[28] The development & use costs associated with LVC can be summarized as follows:[29][30] In contrast, the fidelity of M&S is highest in Live, lower in Virtual, and lowest in Constructive.
