understanding simware platform

Reference: Simware Technical Library

Date: May-2017

Version : 1

© SIMWARE SOLUTIONS S.L., 2017. All rights reserved.

Technical Resources [ Understanding Simware Platform ]

SIMWARE Technical Resources

Understanding Simware architecture Date: May 2017

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Property of SIMWARE SOLUTIONS S.L.

[email protected] – www.simware.es

1 OBJECTIVE

This document describes the main features and capabilities in Simware

platform and some use cases for the platform.

2 INTRO TO SIMWARE PLATFORM

Simware platform is based on a microservices architecture, named Layered

Simulation Architecture or LSA. LSA is the first microservices architecture for

simulation, specifically designed to support the development of real time and

Net-Centric simulation products. As any other microservices architecture, LSA

allows to decompose the simulation product into small and easily manageable

components. Microservices are called Entities in Simware and interoperate with

other entities by exchanging data through a distributed simulation runtime

infrastructure, that is working as the ESB (Enterprise Service Bus) of the simulation

product.

Simware platform provides a loosely coupled architecture, composed by multiple

layers that can work alone or in collaboration, depending on the project’s

requirements. Simware layers provided everything you need to develop real

time simulations that can be connected with web and legacy applications in

any kind of simulation & training solution.

mailto:[email protected]

http://www.simware.es/

http://www.simware.es/lsa.html

http://www.simware.es/products.html



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3 SIMWARE DESIGN’S PATTERN

Simware platform evolves the traditional design pattern of a real time

simulation, based on the structural model pattern or AVSM, first introduced in

the simulation domain by SEI in 19931, to support Net-Centric and data-centric

open simulations.

Simware architecture supports a design pattern with three levels of artefacts:

- The executive level, applications and services that handle coordination

issues: real-time scheduling of subsystems, synchronization between

applications, event management, data sharing, and data integrity.

- The application level, handling the computation of the simulation. Its

functions are implemented by Entities and simulation services that are

composed by simulation models.

- The interface level, handling the integration of third-party components.

External applications can be integrated in Simware platform by using the

1 Technical Report CMU/SEI-93-TR-14. Structural Modeling: An application framework and development process for flight simulators





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open APIs provided in Simware or by using a standard interface as HLA,

DIS, DDS, CIGI, etc.

Integration of all the artefacts at the different level is achieved by the use of a

real time middleware, that provides a publish-subscribe interface to the two

data models in Simware, one for the management of the simulation and the

other for the exchange of simulation data.

Simware provides 4 main artefacts at the Executive level:

- Scheduler. It is doing the functions of the AVSM’s timeline synchronizer. It

keeps the state of the simulation, manage the tick of the clock and

controls the operational status of the Entities. It also commands the

creation and destruction of new instances of the simulation objects,

under the request of the ACS or of any external application.

- A XML configuration file, which defines the simulator structure (number of

hosts and Entities running in each host), simulation conditions (master sim

frequency, number of hosts, conditions for the cyclical execution of the

entities and services, initial conditions, etc.)

- A control data-model, which defines the management object model for

the simulation (state machine, clock, management of instances of the

objects, etc.)

- SimEngine, it is the periodic sequencer in Simware platform. One

instance of the SimEngine is running in each host in which periodic

simulations are executed. SimEngine manages the cyclical execution of

the periodic simulations using the simulation conditions defined in the

configuration file (order, frequency, etc.) and the state and time control

data provided by the scheduler.

Event handler functions are performed in Simware by the simulation

middleware. It is the middleware which process the publications of interactions

(the way to model events in Simware) to the subscribers connected to the

network. Delivery conditions to the subscribers will be specified in the specific

QoS contract for each subscriber.

At the Application level, Simware supports Simulation models that can be

integrated in Entities (subsystems) or can be deployed as Simulation Services.

Entities can be connected to Simulation Services through the middleware.

Entities and Sim services exchange data as is defined in the simulation data

model: simulation objects (permanent data) and interactions (events).





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Interactions are used in Simware to send orders/request between the Entities

and Sim services2.

Entities and Simulation services can be asynchronous components, event-

based applications that don’t need from a SimEngine or synchronized

components working under the command of a SimEngine.

Simware platform provides also the foundation of an IOS: the ACS application.

ACS is a container of control panels created automatically directly from the

simulation data-model and provides a visual interface to manage the

execution of the simulation and the management of instances of the simulation

objects and interactions.

At the Interface Level, Simware provides open APIs and tools to create control

and simulation data interfaces with third-party applications. Simware provides

C++ and Web APIs to integrate other desktop and web applications and tools

and SDKs to develop gateways with systems that are using different standard

protocols as HLA, DIS, JAUS, CIGI, DDS, etc3 Gateway SDK can be also be used

to develop gateways with proprietary protocols. This capability enables the

easy integration of components provided by other partners in the supply chain

of the simulator, including COTS components.

One or several Entities and simulation services can be integrated together as a

Component, that would be a kind of micro-service. This services can be

deployed on dedicated simulation servers, that can connected to several

simulation sessions at the same time (know further at section 5)

2 Learn more about how Simware leverages the interactions to provide interoperability at a component level in the technical paper

“Doing smart connected simulations” at http://www.simware.es/resources.html

3 To learn more about the standards and protocols supported in Simware goes to http://www.simware.es/simware--

standards.html



http://www.simware.es/resources.html

http://www.simware.es/simware--standards.html

http://www.simware.es/simware--standards.html



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4 SIMWARE’S LAYERED ARCHITECTURE

Simware’s bedrock is his data-centric, layered and modular architecture. All

the artefacts explained in above section are organized in separate layers. Our

layered architecture provides a great modularity and flexibility of use.

Simware is composed by next layers:

- Data-exchange layer. Right now, Simware is compliant with DDS and

HLA. Different implementations of both standards can be used to

exchange data in the network between the different applications in

Simware and even with others external to Simware. This is one of the

main features included in Simware: any source-code developed with

Simware can be deployed on HLA or DDS without any change, only by

changing a parameter in the construction of the simulation session.

- Simulation Data-Bus. Simware provides a pure data-centric simulation

middleware to connect different applications. This middleware includes

APIs to manage the data-models used in Simware.





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- Runtime Infrastructure. This layer contains the main artefacts at the

Executive level and its use is optional4 in Simware. You will only need it in

case you are dealing with synchronized simulations using a common

wall-clock or need to deal with the cyclical and deterministic

execution of physics-based simulations. This layer can be used then to

build the host of a real time simulator or to manage the real time

execution of different simulation services running on a simulation server.

Simware, as a pure distributed architecture, allows the distribution of

the cyclical computation of physics based simulation models in

different machines, synchronized by a shared wall-clock and a

common state machine. Two services are provided in the runtime

infrastructure to manage this distributed simulation: Scheduler and

SimEngines. Scheduler manages the clock and command the transition

between the different states of the simulation. A SimEngine is an artifact

running in each machine that it is executing physics-based sim models.

This SimEngine manage the cyclical execution of the sim model based

on the tick of the clock and the state of the simulation.

- SimWeb Server. This optional layer opens Simware data-centric

architecture to web and mobile applications. It leverages LTI standard

(Learning Tool Interoperability) to provide an interface between the

typical client-server architecture in web and mobile apps and the

data-centric architecture in Simware.

- Gateway. This optional layer provides the capability to connect the

basic classes for the publishers and listeners in Simware with systems that

use standard based or proprietary connectivity protocols. This layer then

provides a bridge between the internal data-models in Simware and

heterogeneous systems, that can be both simulations or real systems.

4.1 SIMWARE = DATA-CENTRIC

The main difference in Simware when you compare with any other COTS in the

market it is its pure data-centric architecture. Simware only leverages data to

enable the interactions between all the entities connected to the platform.

Data is used to exchange information about the dynamics and behaviors of

the different simulated objects, including the interactions between them.

4 This layer can be also used to integrate third-party simulation engines and legacy simulation models. See “SIMWARE_RESOURCES :

Integrating legacy sim models” to know how to do it”.



https://www.imsglobal.org/activity/learning-tools-interoperability



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Simware also use data to manage the execution of the simulation in a

distributed environment (control of the state-machine and the clock,

management of instances of the different objects, etc.).

Data-models in Simware are based on HLA standard. Simware uses the HLA

Object Model Template spec as the base to design its own data-models. You

will find two data-models in any Simware simulation:

- Simulation data-model. It can be any data-model. Simulation data-

models in Simware are composed by persistent entities (simulation

objects) and events (interactions in HLA terminology). Data-models are

built with Modeler tool included in Simware Core package. Modeler will

build automatically an instance of the middleware in Simware (called

NCWare Sim) from the HLA-style XML file.

- Control Data-Model. It is a fixed data-model, used to manage the

simulation (its state-machine, the simulation’s wall clock and the

management of the simulation objects).



http://www.simware.es/simware-core.html



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Data-centric middleware maintains the state of the simulation using the control

data model. It manages the simulated content using simulation objects and

interactions with the same structure as specified in HLA standard.

Interactions in Simware are used not only to declare events in the simulation

but also to call the methods and procedures of other entities. For example, a

fighter entity can use interactions to command external simulation services to

launch flares, missiles or bombs. In this way, interactions enable dynamic

interoperability between the simulation entities as it is defined by LCIM (Levels

of Conceptual Interoperability Model)5

During execution of a session with Simware, a simulation data-domain will be

created in the network, to publish and subscribe the objects and interactions

in the Simulation data-Model and to exchange management information

about the state of the simulation using the control data-model.

Simware allows to have several simulations running at the same time in only

one physical network. Different “logical” simulation domains will be managed

for each one of the simulation executions. A Simware simulation domain is the

equivalent of a federation execution in HLA ((know further at section 5)

In each simulation session, you will have several applications that are publishing

and subscribing to any number of objects and interactions. In HLA terminology,

you will call each of them a federate. In Simware we call them Simulation

Entities or Services.

5 Know further at “SIMWARE_RESOURCES : Doing Smart Connected Simulations”





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4.2 SIMWARE = NET-CENTRIC

Our fully distributed architecture is another key feature in Simware. Simware is

the only commercial real time simulation platform in the market fully leveraging

the best advantages of distributed systems. This feature allows to develop Net-

Centric simulators, ready to be deployed in the network and be connected to

other systems there.

Net-Centric architecture, besides to make easier the connectivity with other

systems in the network, enables the distributed computing of the simulation

system. This feature is very important even in the case of a standalone

simulator: standalone simulators used to be deployed on several computers,

Simware allows then to distribute the Entities in the different computers without

any limitation. A very typical example of how to use this capability is to balance

the load of the host of a real-time simulator between different computers.

Simware allows to distribute the artefacts in the Executive and application

levels in any machine of the network of the simulator.





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4.3 SIMWARE = OPEN APIS

Each main layer in Simware has their own API to develop and configure the

services and features included in it:

• NCWare Sim. It is a C++ based API available on Simware Core license

for Windows and Linux. It is the API that is used with the simulation data-

bus to interface with the simulation data-model. With this API, the

developer can:

1. create/destroy simulations sessions or join to one already existing

2. Manage publishers and subscribers for the objects and interactions

in the Simulation data-model.

3. Manage synchronization points that can be used to synchronize

different entities in a Simware simulation.

4. Manage a logger and system traces for code depuration. These

traces can be stored in a file to do a deeper review of the execution

of the simulation.

• Simware Control Library (SCL). It is another C++ API, also provided with

Simware Core, for Linux and Windows. This library provides a set of

classes to get access to the Simware Control datamodel. This includes

methods to manage the simulation state machine, to control the

creation and destruction of instances of the objects and interactions

included in the simulation data-model and to define the initial

condition for the exercises. SCL is then managing the execution of the

artifacts included in Runtime Infrastructure layer (Scheduler and

SimEngine).

• Simware Web API. SimWeb Server provides a RESTful API, compliant with

the LTI std, to connect web and mobile applications to the control and

simulation data-models in Simware. SimWeb Server is generated

automatically from the data-models using the Web generator included

in Simware Web extension. A simplified C++ API is provided with this

extension in order to build LTI based applications that can connect to

the simulation and control data-models in Simware. A LtiClient C++

class is provided with the Simware Web package that helps the C++

developer to create and manage LTI messages. Clients can also be

done in other languages as Java, Python, C#, etc.





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• eHost API. It is an XML based API that allows the configuration of the

execution of the runtime infrastructure and its deployment in the

network. The XML File allows to configure all the parameters that are

required to run a real-time simulation in the network as the overall

simulation frequency, the simulation frequency and execution order for

the sim models, the physical deployment of each sim model in the

network, etc. Basically, eHost, SCL API and the ACS tool (included also

in Simware Core package) allows to configure and manage the

execution of a simulation session as shown in the picture





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5 SIMWARE’S DEPLOYMENT ARCHITECTURE

In execution, Simware is deployed as any micro-services architecture, with a

simulation infrastructure deployed on top of the network. Basic parameters of

the execution (distribution of the Simulation Entities, overall frequency of the

simulation, etc.) are defined in the eHost Config file. Specific mechanism to

exchange data in the network will be declared in the construction of the

middleware (DDS or HLA).

Several sessions of the simulation can be running at the same time on the same

network. Simware supports the concept of Domains, that it is a logical scope

(or "address space") for the data-models definitions. Simulation Domains are

completely independent from each other. For two Simware Entities to

communicate with each other they must join the same simulation Domain. This

feature enables the deployment of simulation servers, that are machines that

can execute several simulation sessions of the Entities at the same time, each

one serving a different simulation domain.

Specific service level agreements between the publishers & subscribers and the

middleware will be defined in a QoS file. Middleware will create messaging

channels in each domain between the publishers and subscribers of each type

of data contained in the control and simulation data models. These channels

will be based on shared memory in the case of flows of data between entities

running on the same machine or UDP based messaging in the case of entities

running on different machines.





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One Scheduler service will be running on one machine of the simulation

network. Command of the simulation can be made through ACS console

provided with the software or by any application using the SCL API to connect

to the control data model.

Periodic simulations will run under the control of a SimEngine. One SimEngine

service will be running in each machine that it is running periodic simulations,

as physic-based simulation models.

Event based Entities can be also running in the simulation infrastructure. This kind

of aperiodic applications can use the synchronization services provided by the

Scheduler Service (common state-machine, common wall-clock) or run

asynchronously only coordinated by specific interactions defined in the

simulation data-model. For example, an interaction can be a Request_LOS that

is processed by an aperiodic Terrain simulation service. Any Entity requesting a

Line of Sight service will publish the interaction and the simulation service will

publish the LOS for the provided location.

Other entities can be connected to the middleware to consume or publish

data. This Entities can be integrated in Simware infrastructure through the C++

and Web APIs or by using a gateway.





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6 AGILE DEVELOPMENT WITH SIMWARE PLATFORM

Simware innovations are not only in the software architecture. Simware

platform has been also designed as a productivity platform6, looking for the

rapid design and development of the simulator.

Simware provides an integrated development environment that supports many

of the best agile&lean software practices as model driven development, test-

driven development and continuous integration/delivery. The uncoupled and

data-centric architecture in Simware allows to develop the simulator in an

incremental way, having flexibility to add or change requirements during the

development process7.

Simware provides visual tools that

allows to generate rapidly the

structure of the simulator directly

from the simulation data-model

that can deployed directly on the

network using HLA or DDS.

Simware Designer tools, included

in Simware Core license,

generate, directly from the data-

model, C++ and XML file

describing the publish-subscribe interface of all the Entities and simulation

services. Simware tools create also directly the instantiation of the integration

infrastructure based on the designed simulation data-model, including the

publish-subscribe interfaces to the middleware, the Web server to connect LTI

based web/mobile applications and the Logger server to record the exercises.

All these artefacts are generated automatically, direct from the data-model.

Designer tools generates C++, LTI and XML interfaces. XML interfaces define in

HLA format the publish-subscribe interface of each subsystem/component. This

XML file, or Interface Definition File, IDF, in Simware terms, is used by

SimDeveloper tool, an extension to the Core in our portfolio, to do model-driven

development of the subsystems/components in the simulation. SimDeveloper

6 Go to http://www.simware.es/products.html to learn more about the commercial packages in Simware portfolio

7 Go to http://www.simware.es/agile-simware.html to learn more about how to adopt Agility with Simware platform



http://www.simware.es/simware-core.html

http://www.simware.es/simdeveloper.html

http://www.simware.es/products.html

http://www.simware.es/agile-simware.html



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is an integrated simulation development environment into Simulink, that allows

to develop, integrate and test the simulations models using Mathworks

products: Simulink, Matlab and StateFlow. Once the simulation modules have

been verified into Simulink environment, automatic generation of C++ code is

provided as a feature in Simdeveloper. SimDeveloper is also very useful in the

case of the development of hi-fi training devices that are using the engineering

data-package of the vehicle and its main systems. In this case, the

manufacturer and its OEMs can provide the data-package as Simulink libraries,

that could be used in SimDeveloper as input to develop the simulation models

for the simulator.

Simware Web extension provides a Web server generator to create

automatically the web interface of the simulator directly from the data-model.

This web server provides a translation to LTI messages of the data-models in

Simware.

Simware Record&Play extension has also the capability to create a Recorder

server directly from the data-model. Simware Recorder Generator generates

automatically a Logger server from the simulation data model.

Simware LVC extension provides PowerLink tool to generate automatically

gateways to DIS and HLA simulators and a Gateway SDK to speed up the

development of interfaces to any other standard or proprietary protocol.



http://www.simware.es/simware-web.html

http://www.simware.es/simware-recordplay.html

http://www.simware.es/simware-lvc.html



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7 EXAMPLES OF USING SIMWARE ARCHITECTURE

In this chapter, you will find several examples of how Simware is used to build

and integrate different types of applications. These are only some examples of

how the different layers in Simware can be combined together to build a

simulation.

7.1 VISUALIZATION APPLICATION.

In the case of a 2D or 3D app, they will

normally only would need to connect

to the simulation Data-model in

Simware. In this case, the developer

will use a software architecture as

shown in the picture

7.2 CONTROL STATION

In the case of a control station, as an

Instructor Operated Station (IOS), the

developer will need also to have

access to the control data-model in

Simware, in order to be able to

manage the execution of the

simulation session.





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7.3 REAL TIME SIMULATION HOST

In the case of developing a simulation engine that it is managing the distributed

execution of different simulation models (working or not synchronized by a

common wall clock), the developer would need to add the runtime

infrastructure to its development.

In this case the basic software

architecture would be as in the

picture. This architecture is useful

to build many real time simulations

as for example:

- The Host of a real time

simulator

- A Simulation Server

- A Computer Generated

Forces Engine.

7.4 INTEGRATION OF WEB/MOBILE

APPLICATIONS

In case that you need to connect web

or mobile apps with your Simware

simulation you would need to add a

SimWeb server to your deployment, in

order to provide the interface

between the LTI’s Send & Request

messages and the data-centric

architecture in Simware.





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7.5 HLA SIMULATION SERVER CONTROLLED BY A WEB’S BASED IOS

You can combine above architectures to build more complex examples. For

instance you could deploy a real time simulation server in the network, as a HLA

federate, providing weapon simulation services to the federation of

simulations. This simulation server could be managed into a DMOC (Distributed

Mission Operation Center) using a web based IOS.

7.6 REAL TIME SERVER PROVIDING SIMULATION SERVICES TO HLA NETWORK

As an advanced case of the former example you could have a HLA federate

providing simulation services from a farm of servers. In this case to support the

distributed computation of the simulation services in several servers, DDS will be

used in order to take advantage of the best performance versus HLA. This DDS

server would need in this case a gateway to be connected to the main HLA

network. From a development point of view, main difference in this example

when comparing the simulation server with the one in former example is that in

this case the integration engineer will modify the eHost config file in order to

change the deployment of the simulation services to more than one node (it

will create more than a SimEngine) and will deploy the NCWare middleware

on DDS instead of HLA. Simulation services will be the same as in the other

example.





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7.7 REAL TIME SIMULATOR WITH MOTION PLATFORM

In another complex integration, the real time components in a training device,

for example the simulation host and the motion platform, could leverage the

distributed architecture in Simware and the deterministic exchange of data

available with DDS to work integrated as in the example. This architecture will

leverage the QoS in DDS to guarantee deterministic performance in the

exchange of data between the physic-based sim models allocated in the host

and the motion platform.





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7.8 FLIGHT SIMULATOR8

Simware can be used as the backbone to build high-fidelity virtual simulators,

as a flight simulator. In this case, DDS based simulation data-bus can be used

as the backbone of the simulator, using the open APIs in Simware to integrate

desktop based and web-based components, developed in-house, by third-

party partners or COTS.

8 To know more about how to use Simware for virtual training, download the technical Resource Developing Training Devices with

Simware at http://www.simware.es/resources.html or visit our page http://www.simware.es/training-devices.html




http://www.simware.es/training-devices.html



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7.9 LVC SIMULATION

Complex LVC simulations, involving multiple architectures and protocols, can

be also be implemented and deployed with Simware. In this case, full

capabilities of Simware will be unleashed, integrating native and legacy

applications in multi-architecture simulation environments in which the

seamless interoperability of HLA, DDS, DIS, Web and other standards will be

managed by the multiple layers in Simware9.

One example is shown in next picture. This picture shows the high level

architecture of a real use case for Simware, the CITIUS Lab. This is an example

of a multi-architecture solution that leverage the data-centric architecture in

Simware and its connectivity capabilities to integrate real and simulated

systems in a common virtual environment. In this case heterogeneous systems

are connected to a common simulation environment using different interfaces

as DDS, HLA, DIS, JAUS or MSDL/CBML.

9 To know more about how to use Simware for LVC simulation go to technical Resource Doing LVC Simulation with Simware at




http://www.simware.es/use-case---citius.html




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8 SUMMARY

This technical document is only showing some of the multiple choices the

developer has when is developing with Simware. Loosely coupled architecture

in Simware allows to combine the different layers in many ways. Modularity

allows only to use the requested layers in each integration, avoiding any

unnecessary overhead and minimizing the impact of the platform in the

performance of the whole product.

You can find more information about the platform and her architecture, the

APIs and the tools, and how to use them in the documents and examples that

are provided with the installation of the different Simware packages. Our web-

site (simware.es) also includes more technical resources as this one that can

help you to master Simware platform quickly. You can also contact our sales

team at [email protected] to know how the specific requirements in your

project could be solved using Simware.

9 ABOUT SIMWARE SOLUTIONS

Simware Solutions is leading the introduction of Open platforms into the

Simulation & Training markets. Our platform, Simware, leverages the new

Layered Simulation Architecture or LSA to fulfill the requirements of the lead

users of the industry, which are demanding open architectures, better

interoperability and increasing economical returns for their investments in

simulation and training solutions.

Our platform is the first commercial product in the market supporting the

Internet of Simulations concept. IoS is about to embrace technologies as

internet, distributed systems, open platforms, cloud computing and service

oriented architectures for the development and deployment of open, net-

centric and interoperable simulations.

Simware is the only simulation platform in the market supporting Net-Centric

simulation without restrictions, enabling new business models for simulation as

the use of simulation as a Service (MSaaS) or the use of simulation platforms as

a service (SPaaS).

Simware is the only simulation platform in the market that is useful in all the

phases of the simulation based system engineering of industrial and consumer

products.





understanding simware platform

Technology