What-If Analysis

7 Nov 202324 minutes to read

What-If Analysis is the process of changing the values in cells to see how those changes will affect the outcome of formulas on the worksheet. XlsIO supports the What-If Analysis of Scenarios type.

Scenario Manager

Scenario Manager in Excel allows you to create and manage scenarios for different sets of input values to see how they impact the results of formulas in a worksheet.

Create Scenario

The following code snippet explains how to create scenarios for different values in an Excel worksheet.

C# [Cross-platform]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    FileStream inputStream = new FileStream("InputTemplate.xlsx", FileMode.Open, FileAccess.Read);
    IWorkbook workbook = application.Workbooks.Open(inputStream, ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;

    //Initialize list objects with different values for scenarios
    List<object> currentChangePercentage_Values = new List<object> { 0.23, 0.8, 1.1, 0.5, 0.35, 0.2};
    List<object> increasedChangePercentage_Values = new List<object> { 0.45, 0.56, 0.9, 0.5, 0.58, 0.43};
    List<object> decreasedChangePercentage_Values = new List<object> { 0.3, 0.2, 0.5, 0.3, 0.5, 0.23};
    List<object> currentQuantity_Values = new List<object> { 1500, 3000, 5000, 4000, 500, 4000 };
    List<object> increasedQuantity_Values = new List<object> { 1000, 5000, 4500, 3900, 10000, 8900 };
    List<object> decreasedQuantity_Values = new List<object> { 1000, 2000, 3000, 3000, 300, 4000 };

    //Add scenarios in the worksheet with different values for the same cells
    scenarios.Add("Current % of Change", worksheet.Range["F5:F10"], currentChangePercentage_Values);
    scenarios.Add("Increased % of Change", worksheet.Range["F5:F10"], increasedChangePercentage_Values);
    scenarios.Add("Decreased % of Change", worksheet.Range["F5:F10"], decreasedChangePercentage_Values);
    scenarios.Add("Current Quantity", worksheet.Range["D5:D10"], currentQuantity_Values);
    scenarios.Add("Increased Quantity", worksheet.Range["D5:D10"], increasedQuantity_Values);
    scenarios.Add("Decreased Quantity", worksheet.Range["D5:D10"], decreasedQuantity_Values);

    //Saving the workbook as stream
    FileStream stream = new FileStream("Output.xlsx", FileMode.Create, FileAccess.ReadWrite);
    workbook.SaveAs(stream);
    stream.Dispose();
}

C# [Windows-specific]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    IWorkbook workbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;

    //Initialize list objects with different values for scenarios
    List<object> currentChangePercentage_Values = new List<object> { 0.23, 0.8, 1.1, 0.5, 0.35, 0.2};
    List<object> increasedChangePercentage_Values = new List<object> { 0.45, 0.56, 0.9, 0.5, 0.58, 0.43};
    List<object> decreasedChangePercentage_Values = new List<object> { 0.3, 0.2, 0.5, 0.3, 0.5, 0.23};
    List<object> currentQuantity_Values = new List<object> { 1500, 3000, 5000, 4000, 500, 4000 };
    List<object> increasedQuantity_Values = new List<object> { 1000, 5000, 4500, 3900, 10000, 8900 };
    List<object> decreasedQuantity_Values = new List<object> { 1000, 2000, 3000, 3000, 300, 4000 };

    //Add scenarios in the worksheet with different values for the same cells
    scenarios.Add("Current % of Change", worksheet.Range["F5:F10"], currentChangePercentage_Values);
    scenarios.Add("Increased % of Change", worksheet.Range["F5:F10"], increasedChangePercentage_Values);
    scenarios.Add("Decreased % of Change", worksheet.Range["F5:F10"], decreasedChangePercentage_Values);
    scenarios.Add("Current Quantity", worksheet.Range["D5:D10"], currentQuantity_Values);
    scenarios.Add("Increased Quantity", worksheet.Range["D5:D10"], increasedQuantity_Values);
    scenarios.Add("Decreased Quantity", worksheet.Range["D5:D10"], decreasedQuantity_Values);

    //Saving the workbook
    workbook.SaveAs("Output.xlsx");
}

VB.NET [Windows-specific]

Using excelEngine As ExcelEngine = New ExcelEngine

    Dim application As IApplication = excelEngine.Excel
    application.DefaultVersion = ExcelVersion.Xlsx
    Dim workbook As IWorkbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic)
    Dim worksheet As IWorksheet = workbook.Worksheets(0)

    Dim scenarios As IScenarios = worksheet.Scenarios

    Dim currentChangePercentage_Values As List(Of Object) = New List(Of Object)() {0.23, 0.8, 1.1, 0.5, 0.35, 0.2}
    Dim increasedChangePercentage_Values As List(Of Object) = New List(Of Object)() {0.45, 0.56, 0.9, 0.5, 0.58, 0.43}
    Dim decreasedChangePercentage_Values As List(Of Object) = New List(Of Object)() {0.3, 0.2, 0.5, 0.3, 0.5, 0.23}
    Dim currentQuantity_Values As List(Of Object) = New List(Of Object)() {1500, 3000, 5000, 4000, 500, 4000}
    Dim increasedQuantity_Values As List(Of Object) = New List(Of Object)() {1000, 5000, 4500, 3900, 10000, 8900}
    Dim decreasedQuantity_Values As List(Of Object) = New List(Of Object)() {1000, 2000, 3000, 3000, 300, 4000}

    'Add scenarios in the worksheet with different values for the same cells
    scenarios.Add("Current % of Change", worksheet.Range("F5:F10"), currentChangePercentage_Values)
    scenarios.Add("Increased % of Change", worksheet.Range("F5:F10"), increasedChangePercentage_Values)
    scenarios.Add("Decreased % of Change", worksheet.Range("F5:F10"), decreasedChangePercentage_Values)
    scenarios.Add("Current Quantity", worksheet.Range("D5:D10"), currentQuantity_Values)
    scenarios.Add("Increased Quantity", worksheet.Range("D5:D10"), increasedQuantity_Values)
    scenarios.Add("Decreased Quantity", worksheet.Range("D5:D10"), decreasedQuantity_Values)

    'Saving the workbook  
    workbook.SaveAs("Output.xlsx")
End Using

A complete working example to create scenarios in C# is present on this GitHub page.

By executing the program, you will get the Excel file as below.

Edit Scenario

An existing scenario can be edited or modified through ModifyScenario method of IScenario.

C# [Cross-platform]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    FileStream inputStream = new FileStream("InputTemplate.xlsx", FileMode.Open, FileAccess.Read);
    IWorkbook workbook = application.Workbooks.Open(inputStream, ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario1 = scenarios[0];
    IScenario scenario2 = scenarios[1];

    //Modify the scenario 
    scenario1.ModifyScenario(scenario2.ChangingCells, scenario2.Values);

    //Saving the workbook as stream
    FileStream stream = new FileStream("Output.xlsx", FileMode.Create, FileAccess.ReadWrite);
    workbook.SaveAs(stream);
    stream.Dispose();
}

C# [Windows-specific]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    IWorkbook workbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario1 = scenarios[0];
    IScenario scenario2 = scenarios[1];

    //Modify the scenario 
    scenario1.ModifyScenario(scenario2.ChangingCells, scenario2.Values);

    //Saving the workbook
    workbook.SaveAs("Output.xlsx");
}

VB.NET [Windows-specific]

Using excelEngine As ExcelEngine = New ExcelEngine

    Dim application As IApplication = excelEngine.Excel
    application.DefaultVersion = ExcelVersion.Xlsx
    Dim workbook As IWorkbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic)
    Dim worksheet As IWorksheet = workbook.Worksheets(0)

    Dim scenarios As IScenarios = worksheet.Scenarios
    Dim scenario1 As IScenario = scenarios(0)
    Dim scenario2 As IScenario = scenarios(1)

    'Modify the scenario 
    scenario1.ModifyScenario(scenario2.ChangingCells, scenario2.Values)

    'Saving the workbook  
    workbook.SaveAs("Output.xlsx")
End Using

Delete Scenario

A scenario can be deleted from the Excel worksheet through Delete method of IScenario.

C# [Cross-platform]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    FileStream inputStream = new FileStream("InputTemplate.xlsx", FileMode.Open, FileAccess.Read);
    IWorkbook workbook = application.Workbooks.Open(inputStream, ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario1 = scenarios[0];

    //Delete the scenario 
    scenario1.Delete();

    //Saving the workbook as stream
    FileStream stream = new FileStream("Output.xlsx", FileMode.Create, FileAccess.ReadWrite);
    workbook.SaveAs(stream);
    stream.Dispose();
}

C# [Windows-specific]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    IWorkbook workbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario1 = scenarios[0];
    IScenario scenario2 = scenarios[1];

    //Delete the scenario 
    scenario1.Delete();

    //Saving the workbook
    workbook.SaveAs("Output.xlsx");
}

VB.NET [Windows-specific]

Using excelEngine As ExcelEngine = New ExcelEngine

    Dim application As IApplication = excelEngine.Excel
    application.DefaultVersion = ExcelVersion.Xlsx
    Dim workbook As IWorkbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic)
    Dim worksheet As IWorksheet = workbook.Worksheets(0)

    Dim scenarios As IScenarios = worksheet.Scenarios
    Dim scenario1 As IScenario = scenarios(0)

    'Delete the scenario
    scenario1.Delete()

    'Saving the workbook  
    workbook.SaveAs("Output.xlsx")
End Using

Merge Scenario

Scenarios in one Excel worksheet can be merged in to another, using Merge method of IScenarios.

C# [Cross-platform]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    FileStream inputStream = new FileStream("InputTemplate.xlsx", FileMode.Open, FileAccess.Read);
    IWorkbook workbook = application.Workbooks.Open(inputStream, ExcelOpenType.Automatic);
    IWorksheet worksheet1 = workbook.Worksheets[0];
    IWorksheet worksheet2 = workbook.Worksheets[1];

    //Merge the second worksheet scenario into first worksheet.
    worksheet1.Scenarios.Merge(worksheet2);

    //Saving the workbook as stream
    FileStream stream = new FileStream("Output.xlsx", FileMode.Create, FileAccess.ReadWrite);
    workbook.SaveAs(stream);
    stream.Dispose();
}

C# [Windows-specific]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    IWorkbook workbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic);
    IWorksheet worksheet1 = workbook.Worksheets[0];
    IWorksheet worksheet2 = workbook.Worksheets[1];

    //Merge the second worksheet scenario into first worksheet.
    worksheet1.Scenarios.Merge(worksheet2);

    //Saving the workbook
    workbook.SaveAs("Output.xlsx");
}

VB.NET [Windows-specific]

Using excelEngine As ExcelEngine = New ExcelEngine

    Dim application As IApplication = excelEngine.Excel
    application.DefaultVersion = ExcelVersion.Xlsx
    Dim workbook As IWorkbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic)
    Dim worksheet1 As IWorksheet = workbook.Worksheets(0)
    Dim worksheet2 As IWorksheet = workbook.Worksheets(1)

    'Merge the second worksheet scenario into first worksheet.
    worksheet1.Scenarios.Merge(worksheet2)

    'Saving the workbook  
    workbook.SaveAs("Output.xlsx")
End Using

Create Summary

CreateSummary method of IScenarios creates a new worksheet that contains a summary report for the scenarios on the specified worksheet.

C# [Cross-platform]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    FileStream inputStream = new FileStream("InputTemplate.xlsx", FileMode.Open, FileAccess.Read);
    IWorkbook workbook = application.Workbooks.Open(inputStream, ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;

    //Initialize list objects with different values for scenarios
    List<object> currentChangePercentage_Values = new List<object> { 0.23, 0.8, 1.1, 0.5, 0.35, 0.2};
    List<object> increasedChangePercentage_Values = new List<object> { 0.45, 0.56, 0.9, 0.5, 0.58, 0.43};
    List<object> decreasedChangePercentage_Values = new List<object> { 0.3, 0.2, 0.5, 0.3, 0.5, 0.23};
    List<object> currentQuantity_Values = new List<object> { 1500, 3000, 5000, 4000, 500, 4000 };
    List<object> increasedQuantity_Values = new List<object> { 1000, 5000, 4500, 3900, 10000, 8900 };
    List<object> decreasedQuantity_Values = new List<object> { 1000, 2000, 3000, 3000, 300, 4000 };

    //Add scenarios in the worksheet with different values for the same cells
    scenarios.Add("Current % of Change", worksheet.Range["F5:F10"], currentChangePercentage_Values);
    scenarios.Add("Increased % of Change", worksheet.Range["F5:F10"], increasedChangePercentage_Values);
    scenarios.Add("Decreased % of Change", worksheet.Range["F5:F10"], decreasedChangePercentage_Values);
    scenarios.Add("Current Quantity", worksheet.Range["D5:D10"], currentQuantity_Values);
    scenarios.Add("Increased Quantity", worksheet.Range["D5:D10"], increasedQuantity_Values);
    scenarios.Add("Decreased Quantity", worksheet.Range["D5:D10"], decreasedQuantity_Values);

    //Create Summary
    worksheet.Scenarios.CreateSummary(worksheet.Range["L7"]);

    //Saving the workbook as stream
    FileStream stream = new FileStream("Output.xlsx", FileMode.Create, FileAccess.ReadWrite);
    workbook.SaveAs(stream);
    stream.Dispose();
}

C# [Windows-specific]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    IWorkbook workbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;

    //Initialize list objects with different values for scenarios
    List<object> currentChangePercentage_Values = new List<object> { 0.23, 0.8, 1.1, 0.5, 0.35, 0.2};
    List<object> increasedChangePercentage_Values = new List<object> { 0.45, 0.56, 0.9, 0.5, 0.58, 0.43};
    List<object> decreasedChangePercentage_Values = new List<object> { 0.3, 0.2, 0.5, 0.3, 0.5, 0.23};
    List<object> currentQuantity_Values = new List<object> { 1500, 3000, 5000, 4000, 500, 4000 };
    List<object> increasedQuantity_Values = new List<object> { 1000, 5000, 4500, 3900, 10000, 8900 };
    List<object> decreasedQuantity_Values = new List<object> { 1000, 2000, 3000, 3000, 300, 4000 };

    //Add scenarios in the worksheet with different values for the same cells
    scenarios.Add("Current % of Change", worksheet.Range["F5:F10"], currentChangePercentage_Values);
    scenarios.Add("Increased % of Change", worksheet.Range["F5:F10"], increasedChangePercentage_Values);
    scenarios.Add("Decreased % of Change", worksheet.Range["F5:F10"], decreasedChangePercentage_Values);
    scenarios.Add("Current Quantity", worksheet.Range["D5:D10"], currentQuantity_Values);
    scenarios.Add("Increased Quantity", worksheet.Range["D5:D10"], increasedQuantity_Values);
    scenarios.Add("Decreased Quantity", worksheet.Range["D5:D10"], decreasedQuantity_Values);

    //Create Summary
    worksheet.Scenarios.CreateSummary(worksheet.Range["L7"]);

    //Saving the workbook
    workbook.SaveAs("Output.xlsx");
}

VB.NET [Windows-specific]

Using excelEngine As ExcelEngine = New ExcelEngine

    Dim application As IApplication = excelEngine.Excel
    application.DefaultVersion = ExcelVersion.Xlsx
    Dim workbook As IWorkbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic)
    Dim worksheet As IWorksheet = workbook.Worksheets(0)

    Dim scenarios As IScenarios = worksheet.Scenarios

    Dim currentChangePercentage_Values As List(Of Object) = New List(Of Object)() {0.23, 0.8, 1.1, 0.5, 0.35, 0.2}
    Dim increasedChangePercentage_Values As List(Of Object) = New List(Of Object)() {0.45, 0.56, 0.9, 0.5, 0.58, 0.43}
    Dim decreasedChangePercentage_Values As List(Of Object) = New List(Of Object)() {0.3, 0.2, 0.5, 0.3, 0.5, 0.23}
    Dim currentQuantity_Values As List(Of Object) = New List(Of Object)() {1500, 3000, 5000, 4000, 500, 4000}
    Dim increasedQuantity_Values As List(Of Object) = New List(Of Object)() {1000, 5000, 4500, 3900, 10000, 8900}
    Dim decreasedQuantity_Values As List(Of Object) = New List(Of Object)() {1000, 2000, 3000, 3000, 300, 4000}

    'Add scenarios in the worksheet with different values for the same cells
    scenarios.Add("Current % of Change", worksheet.Range("F5:F10"), currentChangePercentage_Values)
    scenarios.Add("Increased % of Change", worksheet.Range("F5:F10"), increasedChangePercentage_Values)
    scenarios.Add("Decreased % of Change", worksheet.Range("F5:F10"), decreasedChangePercentage_Values)
    scenarios.Add("Current Quantity", worksheet.Range("D5:D10"), currentQuantity_Values)
    scenarios.Add("Increased Quantity", worksheet.Range("D5:D10"), increasedQuantity_Values)
    scenarios.Add("Decreased Quantity", worksheet.Range("D5:D10"), decreasedQuantity_Values)

    'Create Summary
    worksheet.Scenarios.CreateSummary(worksheet.Range("L7"))

    'Saving the workbook  
    workbook.SaveAs("Output.xlsx")
End Using

Apply Scenario

Update the scenario values in the worksheet and display it using the Show method.

C# [Cross-platform]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    FileStream inputStream = new FileStream("InputTemplate.xlsx", FileMode.Open, FileAccess.Read);
    IWorkbook workbook = application.Workbooks.Open(inputStream, ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario1 = scenarios[0];
    IScenario scenario2 = scenarios[1];

    //Show the scenario 
    scenario2.Show();

    //Saving the workbook as stream
    FileStream stream = new FileStream("Output.xlsx", FileMode.Create, FileAccess.ReadWrite);
    workbook.SaveAs(stream);
    stream.Dispose();
}

C# [Windows-specific]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    IWorkbook workbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario1 = scenarios[0];
    IScenario scenario2 = scenarios[1];

    //Show the scenario 
    scenario2.Show();

    //Saving the workbook
    workbook.SaveAs("Output.xlsx");
}

VB.NET [Windows-specific]

Using excelEngine As ExcelEngine = New ExcelEngine

    Dim application As IApplication = excelEngine.Excel
    application.DefaultVersion = ExcelVersion.Xlsx
    Dim workbook As IWorkbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic)
    Dim worksheet As IWorksheet = workbook.Worksheets(0)

    Dim scenarios As IScenarios = worksheet.Scenarios
    Dim scenario1 As IScenario = scenarios(0)
    Dim scenario2 As IScenario = scenarios(1)

    'Show the scenario 
    scenario2.Show()

    'Saving the workbook  
    workbook.SaveAs("Output.xlsx")
End Using

A complete working example to show scenario in C# is present on this GitHub page.

Set Name

The name of the scenario can be defined using the Name property..

C# [Cross-platform]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    FileStream inputStream = new FileStream("InputTemplate.xlsx", FileMode.Open, FileAccess.Read);
    IWorkbook workbook = application.Workbooks.Open(inputStream, ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario = scenarios[0];

    //Set the name of the scenario
    scenario.Name = "Current Quantity";

    //Saving the workbook as stream
    FileStream stream = new FileStream("Output.xlsx", FileMode.Create, FileAccess.ReadWrite);
    workbook.SaveAs(stream);
    stream.Dispose();
}

C# [Windows-specific]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    IWorkbook workbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario = scenarios[0];

    //Set the name of the scenario
    scenario.Name = "Current Quantity";

    //Saving the workbook
    workbook.SaveAs("Output.xlsx");
}

VB.NET [Windows-specific]

Using excelEngine As ExcelEngine = New ExcelEngine

    Dim application As IApplication = excelEngine.Excel
    application.DefaultVersion = ExcelVersion.Xlsx
    Dim workbook As IWorkbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic)
    Dim worksheet As IWorksheet = workbook.Worksheets(0)

    Dim scenarios As IScenarios = worksheet.Scenarios
    Dim scenario As IScenario = scenarios(0)

    'Set the name of the scenario
    scenario.Name = "Current Quantity"
    'Saving the workbook  
    workbook.SaveAs("Output.xlsx")
End Using

Hide Scenario

The scenario can be hidden by enabling the Hidden property of IScenario.

C# [Cross-platform]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    FileStream inputStream = new FileStream("InputTemplate.xlsx", FileMode.Open, FileAccess.Read);
    IWorkbook workbook = application.Workbooks.Open(inputStream, ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario = scenarios[0];

    //Hidden the scenario
    scenario.Hidden = true;

    //Saving the workbook as stream
    FileStream stream = new FileStream("Output.xlsx", FileMode.Create, FileAccess.ReadWrite);
    workbook.SaveAs(stream);
    stream.Dispose();
}

C# [Windows-specific]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    IWorkbook workbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario = scenarios[0];

    //Hidden the scenario
    scenario.Hidden = true;

    //Saving the workbook
    workbook.SaveAs("Output.xlsx");
}

VB.NET [Windows-specific]

Using excelEngine As ExcelEngine = New ExcelEngine

    Dim application As IApplication = excelEngine.Excel
    application.DefaultVersion = ExcelVersion.Xlsx
    Dim workbook As IWorkbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic)
    Dim worksheet As IWorksheet = workbook.Worksheets(0)

    Dim scenarios As IScenarios = worksheet.Scenarios
    Dim scenario As IScenario = scenarios(0)

    'Hidden the scenario
    scenario.Hidden = True

    'Saving the workbook  
    workbook.SaveAs("Output.xlsx")
End Using

A complete working example to hide a scenario in C# is present on this GitHub page.

Protect Scenario

The scenario can be locked or unlocked through Locked property of IScenario. A scenario is locked by default.

C# [Cross-platform]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    FileStream inputStream = new FileStream("InputTemplate.xlsx", FileMode.Open, FileAccess.Read);
    IWorkbook workbook = application.Workbooks.Open(inputStream, ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario = scenarios[0];

    //Unlock a scenario
    scenario.Locked = false;

    //Saving the workbook as stream
    FileStream stream = new FileStream("Output.xlsx", FileMode.Create, FileAccess.ReadWrite);
    workbook.SaveAs(stream);
    stream.Dispose();
}

C# [Windows-specific]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    IWorkbook workbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario = scenarios[0];

    //Unlock a scenario
    scenario.Locked = false;

    //Saving the workbook
    workbook.SaveAs("Output.xlsx");
}

VB.NET [Windows-specific]

Using excelEngine As ExcelEngine = New ExcelEngine

    Dim application As IApplication = excelEngine.Excel
    application.DefaultVersion = ExcelVersion.Xlsx
    Dim workbook As IWorkbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic)
    Dim worksheet As IWorksheet = workbook.Worksheets(0)

    Dim scenarios As IScenarios = worksheet.Scenarios
    Dim scenario As IScenario = scenarios(0)

    'Unlock a scenario
    scenario.Locked = False

    'Saving the workbook  
    workbook.SaveAs("Output.xlsx")
End Using

A complete working example to unprotect a scenario in C# is present on this GitHub page.

Add Comment

The comment associated with that particular scenario can be generated using the Comment property.

C# [Cross-platform]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    FileStream inputStream = new FileStream("InputTemplate.xlsx", FileMode.Open, FileAccess.Read);
    IWorkbook workbook = application.Workbooks.Open(inputStream, ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario = scenarios[0];

    //Set the comment value 
    scenario.Comment = "Scenario has been created";

    //Saving the workbook as stream
    FileStream stream = new FileStream("Output.xlsx", FileMode.Create, FileAccess.ReadWrite);
    workbook.SaveAs(stream);
    stream.Dispose();
}

C# [Windows-specific]

using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    IWorkbook workbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic);
    IWorksheet worksheet = workbook.Worksheets[0];

    IScenarios scenarios = worksheet.Scenarios;
    IScenario scenario = scenarios[0];

    //Set the comment value 
    scenario.Comment = "Scenario has been created";

    //Saving the workbook
    workbook.SaveAs("Output.xlsx");
}

VB.NET [Windows-specific]

Using excelEngine As ExcelEngine = New ExcelEngine

    Dim application As IApplication = excelEngine.Excel
    application.DefaultVersion = ExcelVersion.Xlsx
    Dim workbook As IWorkbook = application.Workbooks.Open("InputTemplate.xlsx", ExcelOpenType.Automatic)
    Dim worksheet As IWorksheet = workbook.Worksheets(0)

    Dim scenarios As IScenarios = worksheet.Scenarios
    Dim scenario As IScenario = scenarios[0]

    'Set the comment value 
    scenario.Comment = "Scenario has been created"

    'Saving the workbook  
    workbook.SaveAs("Output.xlsx")
End Using