Menu | >>>> | Overview of the VORSIM Model Building Framework for Excel

VORSIM is a set of computer programs that helps you build, operate, and manage mathematical models in the Microsoft Excel spreadsheet. The software can be used to create dynamic time series models, static partial equilibrium economic models, engineering process models, alternative business plan projections, Armington bilateral trade flow models, or any other type of simultaneous or multi-equation simulation model that can be constructed in a spreadsheet.  While you specify the structure and equations for a model, VORSIM automates some of the most tedious parts of model building while retaining all of the convenience of spreadsheets.  Operations are menu driven in the Windows tradition and are initiated with buttons automatically placed on appropriate workbook sheets. VORSIM imposes an order for equations and data so they modeler always knows where they are located in the spreadsheets.

VORSIM is useful for the construction of all types of models, especially large spreadsheet models with standardized equation systems.  Once a model is constructed, equation parameters and equations can be quickly changed and re-initialized to fit the base data.  Models can be rapidly assembled and can be repeatedly re-simulated for alternative scenarios. Alternative models based on an original can be created and saved. Solutions can be saved and named as soon as they are completed.  Saved solution values can be viewed immediately with Excel pivot tables, filtered lists, and charts.  Model components and solutions are accessible for viewing and are pre-formatted for printing, meaning that a VORSIM-built model is documented as it is constructed. When completed, a ‘transparent’ model is easily passed on to others who were not involved in the construction.

Version 14 of VORSIM for Excel is faster, more flexible, and easier to use than earlier versions; furthermore it will run in Excel 2000-2010. Version 15 runs in Excel 2013 and later Excel versions and is better and faster still. In addition, VORSIM should operate in other language versions of Excel (e.g. Spanish Excel) although VORSIM menus are still in English. Almost all operations are now menu driven. Equations can be easily added to, removed from, or changed in, models using improved equation bank procedures. Models can be expanded by adding variables or shrunk by deleting them. The creation and use of indicators has been simplified. A model manager control screen consolidates most management operations and the number of useful model management techniques has expanded. The User’s Guide gives an overview of VORSIM by presenting the file structure, the methodology for working with equations, and examples using the demonstration models DEMO and STAT. The User’s Guide explains VORSIM control screen operations as a series of topics including the definition and creation of a model, the simulation of a model, the management of solutions, the preparation of reports, and general model management. While the Guide uses VORSIM 14 examples, procedures are generally the same in VORSIM 15.

Notation used in the User’s Guide and VORSIM program screens and menus: […] - a control button, |…| - a pull-down menu item, <…> - a workbook, {…} – a sheet in a workbook, =>…<= - an equation. Button names generally describe what the button does. Menus contain notes and examples that guide menu operations.