ExtendSim Cloud

ExtendSim CloudCompanies use our self-hosted Cloud product to provide ExtendSim models in the cloud for use by their internal or external end-users. Cloud deployment allows the company's clients, such as its employees or customers, to have remote access to ExtendSim simulations without installing the ExtendSim application on their devices.

Once a company has set up the ExtendSim Cloud framework on a server, its clients submit credentials to get access to the ExtendSim models. Using a customized GUI front end (a web page in a browser or a standalone application) on their devices, the clients can send inputs through the cloud to the models, run the simulations, and receive the results on their computer, tablet, or smartphone.

The ExtendSim Cloud license has the advantages of remote access via the web, centralized feature updating, and lower or even non-existent learning curves for non-modelers. It allows end users who have no simulation experience to benefit from the power of ExtendSim.

  • Imagine plant managers receiving comprehensible and immediate feedback on their tablet regarding line management as they walk the factory floor.
  • Or giving that same manager the ability, based on results achieved from data entered into a simple form, to make a change on the fly that greatly improves production output.
  • Or your sales rep pulling out their smartphone on a sales call to show a prospect their potentially improved bottom line if they use your product.

An ExtendSim Cloud license is a great solution for organizations who:

  • Want a cloud-based, self-hosted product that provides access to the functionality of ExtendSim without deploying the application to end users.
  • Prefer centralized control and management of ExtendSim models.
  • Choose to access the functionality of ExtendSim via an intranet or the internet.
  • Want to present end users with a standardized frontend interface, across multiple models, for data entry and the reporting of results.
  • Have few or no end users with simulation interest or expertise.
  • Prefer a web-based approach to software deployment.

Technical Overview

Cloud ArchitectureThe ExtendSim Cloud architecture has been implemented in a framework that consists of a backend in which responses are made to requests for Cloud services and a licensee-customized frontend from which these requests are made. The combination of an ExtendSim Cloud license with a custom frontend environment has the advantages of remote access via the web, centralized feature updating, and lower or even non-existent learning curves for non-modelers.

  • The backend consists of the Cloud Services Manager, the ExtendSim Cloud application, and a data repository, all of which are installed on one or more Cloud Servers.
    • The Cloud Services Manager is the control point through which all interactions between a client and the ExtendSim Cloud application are routed. It was developed in node.js and responds to http and https client requests via routes (API). Using the JavaScript runtime environment to implement API functions, the Services Manager responds to client requests such as launching instances of ExtendSim and returning results (for the complete list of requests, see the User Guide).
    • In response to requests from the Cloud Services Manager, the ExtendSim Cloud application generates multiple instances of itself, running in memory on your Cloud Server. The Cloud Services Manager orchestrates the utilization of individual ExtendSim instances to maximize the throughput of client requests for simulation runs.
    • MongoDB is used as a data repository, storing client information such as user groups and credentials.
  • The frontend uses REST web service access protocols to send data to ExtendSim, run a model, and retrieve results, accessing the functionality of ExtendSim while presenting end users with a standardized front end, across multiple models, for data entry and the reporting of results. As the frontend, the Cloud product includes a web-based frontend template implemented in HTML, CSS, and JavaScript that can be modified as a browser-based frontend or used to test a custom-developed front end. Alternatively, the licensee organization or a third party can develop a custom frontend in any language (JavaScript, PHP, Python, C#, etc.) capable of using the Cloud Services Manager’s API functions to communicate with a RESTful service.

The backend applications and files get installed on one or more of the licensee’s Cloud Servers, which can be virtual or physical. End user access can be over a LAN or over the internet or other WAN. Requests for Cloud services push information from the client device to the Cloud Server and trigger simulation runs on the server. When simulation runs are completed, requests are made at the frontend interface on the client device to pull simulation results from the Cloud Server to the client device. By default, scenarios are run in headless mode.

End-user clients are organized into groups with authenticated log-in credentials and access restricted to specified models. Additional security during a user session is provided by using JWT Tokens.

ExtendSim Cloud uses a License Manager (rlm.exe) to control the number of instances of ExtendSim that are running. The License Manager can be installed on either a separate License Server or on the same device being used as the Cloud Server. The number of running instances is limited by the ordering document’s maximum number of concurrent instances and the number of cores on the Cloud Server.

Capabilities and Limitations of ExtendSim Cloud

  • Push inputs -- from a web page or a custom client application -- to any ExtendSim model that they have been given authentication access to on a server.
  • Remotely trigger a simulation run for that ExtendSim model on a server using the inputs pushed from a client machine.
  • Receive the results from that model on a client machine.
  • There are no limits to the size of the model you can run using an ExtendSim Cloud license, how many runs you can do, or how long the runs are.
  • Like the Analysis RunTime product, the ExtendSim Cloud app can call COM DLLs and use COM for control of/by other applications.
  • Can run and analyze Reliability models with an unlimited number of event cycles.


  • ExtendSim Cloud does not allow the building of models or of blocks, nor can one change the configuration of a model.
  • The licensee is responsible for developing the front end interface.