GoldSim

Frequently Asked Questions

GoldSim Features and Capabilities

  • Q: What are the computer requirements for GoldSim?
    A:

    GoldSim is a Windows® desktop application. Windows 7 (either 32-bit or 64-bit versions), Windows 8.1 and Windows 10 are the supported operating systems. Windows XP, Windows Server 2008 and older, Windows RT and ARM-based CPUs are not supported.

  • Q: What is the difference between GoldSim, GoldSim Evaluation, GoldSim Research, GoldSim Academic and GoldSim Player?
    A:

    GoldSim is the commercial version of the product. GoldSim Evaluation is a fully functional version of GoldSim that expires 30 days after you register it. GoldSim Research is a fully functional license made available at a reduced price to professors and students at qualified academic institutions for research purposes. GoldSim Academic is a restricted license (there is a limit on the size of models) made available for free to professors and students at qualified academic institutions for teaching purposes. GoldSim Player is a free product that allows others to view, edit in a limited way, and run GoldSim models that have been built by others. It provides a mechanism for you to distribute your models to others who do not have a GoldSim license.

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  • Q: What is the best way to quickly get an overview of GoldSim's features and capabilities?
    A:

    This website includes lots of information to give you an overview of GoldSim's features and capabilities. The best place to start is probably with the GoldSim Quick Tour. After that, it would probably be helpful to browse through a description of common GoldSim applications. If you have a bit more time, you can request an evaluation version. GoldSim comes with an excellent tutorial that walks you through the basic features of the software and quickly gives you some hands-on experience. Finally, you can also request a live web-based demo.

  • Q: Do you provide live web-based demos?
    A:

    Yes, you can request an online demo. The demos are provided by technical staff (not sales persons). During the demonstration, the GoldSim specialist shares his or her desktop with you so you can view it through your Internet browser (using GoToMeeting), in order to explain the software's key features, show you some actual models, and answer any specific questions you might have. Note, however, that because demos are provided by our technical staff, we can only provide them to qualified prospects (e.g., we do not provide demos to those interested in free academic licenses).

  • Q: How does GoldSim represent time in a model?
    A:

    GoldSim is a dynamic simulator. As such, the objects used to build a model inherently understand the concept of time. For example, some objects represent integrals over time; others represent delays. You can also write equations that are a direct function of time: e.g., "if(Time > 1 yr, X, Y)". When you build a GoldSim model, you specify the duration of the simulation and the number of timesteps (i.e., the degree to which you want to discretize time). GoldSim then steps through time, allowing variables to evolve and change through simulated time. GoldSim also provides powerful tools for controlling the timestep length dynamically to ensure accurate solutions.

  • Q: How does GoldSim represent uncertainty in a model?
    A:

    GoldSim uses Monte Carlo simulation to simulate systems with uncertain or stochastic components. Monte Carlo (or probabilistic) simulation is a type of simulation that explicitly and quantitatively represents uncertainties. As a result, the outputs of a Monte Carlo simulation are not single values, but are probability distributions.

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  • Q: Can GoldSim represent the occurrence and consequences of discrete events or disruptions, such as accidents, labor strikes, or sudden failure of a mechanical device?
    A:

    GoldSim provides powerful capabilities for superimposing the occurrence and effects of discontinuities and discrete events onto continuously varying systems. This allows for the realistic simulation of discrete events such as financial transactions, accidents, system failures, storms, labor strikes, and lawsuits. Events such as these can have important effects on the performance of many systems, and it is therefore important to represent them in a realistic manner. GoldSim provides a variety of specialized elements for simulating the occurrence and consequences of discrete events. Events can be generated regularly ("occur exactly once a year on January 1"), randomly ("occur, on average, once a year"), or based on a certain set of conditions ("when A is greater than B and the value of C has changed"). An event can trigger one or more consequences, such as changing the status of something in the model ("this task is now complete"), achieving a specified milestone, or making a discrete change to some quantity in your model ("add $1000 to the account").

  • Q: How does GoldSim manage dimensions and units?
    A:

    GoldSim has an extensive internal database of units and conversion factors. You can enter data and display results in any units. You can even define your own units. When elements are linked, GoldSim ensures dimensional consistency and carries out the unit conversions internally. As a result, it is never necessary for you to carry out (error-prone) unit conversions or worry about dimensional consistency. GoldSim checks for consistency and carries out the conversions for you automatically.

  • Q: How big of a model can GoldSim handle?
    A:

    There is no inherent limit to the size of a GoldSim model. Although many useful models are relatively small (several hundred objects), GoldSim's hierarchical structure and powerful navigations features enable very large models to be built (the largest models to date have on the order of 30,000 objects, many of which are arrays). Moreover, GoldSim's distributed processing capability enables you to carry out Monte Carlo simulation even on very large (and computationally intensive) models.

  • Q: Can GoldSim interface to spreadsheets, databases and other programs?
    A:

    Yes. GoldSim allows you to dynamically link a spreadsheet directly into your model. In the simplest use of a such a spreadsheet link, you can use the spreadsheet as a data source. In addition to importing data from a spreadsheet, you can use a spreadsheet as a custom element (with specific functionality). That is, you can dynamically send data from GoldSim to a spreadsheet, force the spreadsheet to recalculate, and then retrieve (updated) data from the spreadsheet back into GoldSim during a simulation (e.g., every timestep). You can also readily export GoldSim results to a spreadsheet.

    GoldSim also allows input elements to be linked directly to an ODBC-compliant database. After defining the linkage, you can then instruct GoldSim to download the data at any time. When it does this, GoldSim internally records the time and date at which the download occurred, and this information is stored with the model results.

    You can also dynamically link an external computer program (add a DLL) directly to GoldSim. In most cases, you need to only make minor modifications to the external program code to which you want to link in order for it to communicate with (i.e., be dynamically called by) GoldSim.

  • Q: Can GoldSim be used for optimization problems?
    A:

    GoldSim is not an optimization program per se (e.g., you would not use it to carry out a large optimization problem involving thousands of optimization variables). However, it does have a powerful capabilities for globally optimizing a moderate number of decision variables in a dynamic simulation model. For this type of run, you specify an objective function (a specific result that you would like to minimize or maximize), an optional constraint (a condition that must be met), and one or more optimization variables (variables in your model that you have control over). GoldSim then runs the model multiple times, systematically selecting combinations of values for each of the optimization variables. By doing so, GoldSim can determine the values of the optimization variables that optimize (minimize or maximize) the objective function while meeting the specified constraint.

    Typical uses of GoldSim's optimization features include: finding the best input data values for a model in order to match observed historical data (i.e., calibration); selecting the "best" option from among alternatives; and optimizing the timing of actions or policy changes during the course of a simulation.

  • Q: Does GoldSim have any tools to facilitate quality assurance when building models?
    A:

    GoldSim has a number of features to support quality assurance. This includes the ability to lock portions of a model and protect them with a password (and know when they have been edited), and the ability to link to external databases and spreadsheets (and tell the user if those data sources have been changed). Most importantly in this regard, GoldSim provides an internal version management capability that provides the ability to record versions (revisions) of a particular model file, so that you can identify the differences between the various versions of the file as the model is iteratively modified. (Which elements have changed? Which elements were deleted? Which elements have been added?)

  • Q: In what ways is GoldSim extensible?
    A:

    GoldSim is extensible in two primary ways. First of all, to platform itself is constantly being extended through the creation (by GoldSim Technology Group) of extension modules to address specialized applications (e.g., reliability of engineered systems, contaminant transport, financial modeling). Secondly, by dynamically linking to spreadsheets or your own custom code (in the form of DLLs), you can incorporate other programs directly into the GoldSim framework.

  • Q: How does GoldSim present simulation results?
    A:

    GoldSim has powerful charting and display functions that allow you to plot and view your data in a variety of ways. You can plot time histories of your results, view probability distributions, create scatter plots, view correlation matrices, and view tables. GoldSim also allows you to export simulation results (to an ASCII file, a binary file, a database or a spreadsheet), from where it can be readily loaded into a statistical post-processor or advanced graphical package.

  • Q: What is the Financial Module?
    A:

    The GoldSim Financial (FN) Module is a add-on extension to GoldSim that allows you to probabilistically simulate financial systems that include components such as accounts and funds, investments, options, projects or undertakings with specified cash flows, and insurance policies. By combining the specialized financial elements in the Financial Module with GoldSim's underlying probabilistic, dynamic simulation framework, you can quickly simulate and analyze complex financial systems, as well as complex engineering and business systems that have a financial component.

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  • Q: What is the Reliability Module?
    A:

    The GoldSim Reliability (RL) Module is an add-on extension to the GoldSim simulation framework that allows you to probabilistically simulate the reliability and performance of complex engineered systems over time. GoldSim provides the ability to model the interdependence of components through requirements and fault trees, as well as the capability to define multiple independent failure modes for each component. This facilitates both reliability modeling and risk analysis within a variety of industries, including space and defense, manufacturing, mining, telecommunications, electronics and infrastructure.

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  • Q: What is the Contaminant Transport Module? What is the Radionuclide Transport Module?
    A:

    The GoldSim Contaminant Transport Module is an add-on extension to the GoldSim simulation framework that allows you to dynamically model mass transport within complex engineered and/or natural environmental systems. The Contaminant Transport Module is available in two versions. GoldSim CT includes all the functionality necessary to simulate the transport of chemical constituents. GoldSim RT is an expanded version of the Contaminant Transport Module that provides additional capabilities designed to support simulation of the release and transport of radioactive constituents from disposal sites.

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  • Q: What is the Distributed Processing Module and how can it be used?
    A:

    The GoldSim Distributed Processing Module is an add-on module that allows you to combine the power of multiple computers connected over a network to carry out a simulation involving multiple Monte Carlo realizations. This is accomplished by a having a master GoldSim executable connect to any number of slave GoldSim executables installed on separate computers. The master executable assigns and sends individual realizations to the slaves. Each slave carries out its assigned realization, sends the results to the master, and then makes itself available to work on another realization. Once all of the realizations have been completed, the master combines all of the results into a single GoldSim file (and enters Result Mode) just as if the entire simulation had been carried out on the master machine.

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  • Q: What is the Dashboard Authoring Module?
    A:

    The GoldSim Dashboard Authoring Module provides a specialized set of tools (included for free in GoldSim Pro and GoldSim Academic) that allows you to create custom designed interfaces, or "dashboards" for your models to make them accessible to non-technical users. Models created using the GoldSim Authoring tools can be saved as Player files and subsequently viewed and run using GoldSim Player, which can be downloaded for free from the GoldSim website. The interfaces can be designed to include buttons, input fields, sliders and result displays, and the author can imbed text, tool-tips and graphics to provide instructions on the use of the model.

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  • Q: Can I distribute models to others who do not have GoldSim?
    A:

    Yes. You can save your models as Player files, which can then be read by the (free) GoldSim Player. If you add Dashboards to your models (see previous question), others can not only view your models in the Player, but they can also edit them (in a limited way) and run them.

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  • Q: How does GoldSim maintain Quality Assurance in the development process?
    A:

    GoldSim is developed and maintained according to a rigorous set of Software Configuration Management Procedures to ensure quality. These procedures include requirements for the following:

    Source Code Revision Control: Each time a file (e.g., a source code module) is modified, a new revision (or version) of the file is created. Revision control provides a mechanism for saving and managing all the revisions of a file in an archive (i.e., a database), dating from the time the file was first entered into the revision control system.

    Change Control and Tracking: Change tracking is the act of managing software problem reports and change requests submitted by users and/or members of the software development team. A problem report is associated with an apparent or actual defect (i.e., a bug) in the code or documentation. A change request is associated with a suggested modification or improvement to the software or documentation. A change tracking system is a database of all reported defects and requests. This database describes all changes made to the software.

    Testing and Verification: All code modifications are thoroughly tested by the software development team. Prior to release of a new version, the program also undergoes an extensive set of verification tests to ensure that the changes work as intended and have not introduced any new problems. The tests are described in a Verification Plan, and the results of the verification are documented in a Verification Report.

    Documentation: Throughout the process of addressing a modification to the source code, requirements and design specifications are produced (if the change is significant). Typically the requirements and design evolve somewhat as the task is evaluated in more detail. As such, these documents (which may be formal documents or simply descriptions in the change tracking system), are temporary tools for communication, and cease to be used or referred to after the changes are made. The final requirements and design details are integrated into the User Documentation, which becomes the "as built" and definitive statement of the new functionality.