diff --git a/DAL/ExcelDataService.cs b/DAL/ExcelDataService.cs
index dcbb93e..42ba5dd 100644
--- a/DAL/ExcelDataService.cs
+++ b/DAL/ExcelDataService.cs
@@ -4,66 +4,130 @@ using DocumentFormat.OpenXml.Spreadsheet;
 
 public class ExcelDataService : IDataService
 {
-    private SpreadsheetDocument? _xlsxFile;
-    private Workbook? _xlsxWorkbook;
-    private WorkbookPart? _xlsxWorkbookPart;
-    private WorksheetPart? _xlsxWorksheetPart;
-    private Sheets? _xlsxSheets;
-    private Sheet? _xlsxSheet;
-    private Cell? _cell;
     private string _fileName;
     private string _pathName;
     private string _dateTime;
 
     public ExcelDataService()
     {
-        _dateTime = DateTime.Now.ToString("yyyyMMdd");
+        _dateTime = DateTime.Now.ToString("yyyyMMddhhmm");
         _fileName = $"CommitReport-{_dateTime}.xlsx";
         _pathName = Directory.GetCurrentDirectory() + "/" + _fileName;
-        System.Console.WriteLine(_pathName);
-        _xlsxFile = SpreadsheetDocument.Create(_pathName, SpreadsheetDocumentType.Workbook);
-        _xlsxWorkbookPart = _xlsxFile.AddWorkbookPart();
-        _xlsxWorkbookPart.Workbook = new Workbook();
-        _xlsxWorksheetPart = _xlsxWorkbookPart.AddNewPart<WorksheetPart>();
-        _xlsxWorksheetPart.Worksheet = new Worksheet(new SheetData());
-        _xlsxSheets = _xlsxFile.WorkbookPart.Workbook.AppendChild<Sheets>(new Sheets());
-        _xlsxSheet = new Sheet() { Id = _xlsxFile.WorkbookPart.GetIdOfPart(_xlsxWorksheetPart), SheetId = 1, Name = "Commit Report" };
-        _xlsxSheets.Append(_xlsxSheet);
-        _xlsxWorkbookPart.Workbook.Save();
-        _xlsxFile.Close();
     }
     
     public void WriteAll(SortedList<string, int> dictResults)
     {
-        using (SpreadsheetDocument spreadSheet = SpreadsheetDocument.Open(_pathName, true))
+        int index = 1;
+        
+        if (!File.Exists(_pathName))
         {
-            WorksheetPart worksheetPart = spreadSheet.WorkbookPart.WorksheetParts.First();
-            
-            foreach (var d in dictResults)
-            {
-                var index = dictResults.GetEnumerator().Current;
-                _cell = InsertCellInWorksheet("A", (index.Value), worksheetPart);
-                _cell.CellValue = new CellValue(d.Key);
-                _cell.DataType = new EnumValue<CellValues>(CellValues.SharedString);
-                worksheetPart.Worksheet.Save();
-                
-                //_cell = InsertCellInWorksheet("B", (index.Value), worksheetPart);
-                //_cell.CellValue = new CellValue(d.Value);
-                //_cell.DataType = new EnumValue<CellValues>(CellValues.SharedString);
-                //worksheetPart.Worksheet.Save();
-            }
-
-
+            this.CreateSpreadsheetWorkbook(_pathName);
+        }
 
+        foreach (var d in dictResults)
+        {
+            this.InsertText(_pathName, d.Key, index, "A");
+            this.InsertText(_pathName, d.Value.ToString(), index, "B");
+            index++;
         }
     }
 
-    private static Cell InsertCellInWorksheet(string columnName, int rowIndex, WorksheetPart worksheetPart)
+    private void CreateSpreadsheetWorkbook(string filepath)
+    {
+        SpreadsheetDocument spreadsheetDocument = SpreadsheetDocument.
+            Create(filepath, SpreadsheetDocumentType.Workbook);
+
+        WorkbookPart workbookpart = spreadsheetDocument.AddWorkbookPart();
+        workbookpart.Workbook = new Workbook();
+
+        WorksheetPart worksheetPart = workbookpart.AddNewPart<WorksheetPart>();
+        worksheetPart.Worksheet = new Worksheet(new SheetData());
+
+        Sheets sheets = spreadsheetDocument.WorkbookPart.Workbook.
+            AppendChild<Sheets>(new Sheets());
+
+        Sheet sheet = new Sheet() { Id = spreadsheetDocument.WorkbookPart.
+            GetIdOfPart(worksheetPart), SheetId = 1, Name = "Commit Report" };
+        sheets.Append(sheet);
+
+        workbookpart.Workbook.Save();
+        spreadsheetDocument.Close();
+    }
+
+    // Given a document name and text, 
+    private void InsertText(string docName, string text, int iterator, string column)
+    {
+        // Open the document for editing.
+        using (SpreadsheetDocument spreadSheet = SpreadsheetDocument.Open(docName, true))
+        {
+            // Get the SharedStringTablePart. If it does not exist, create a new one.
+            SharedStringTablePart shareStringPart;
+            if (spreadSheet.WorkbookPart.GetPartsOfType<SharedStringTablePart>().Count() > 0)
+            {
+                shareStringPart = spreadSheet.WorkbookPart.GetPartsOfType<SharedStringTablePart>().First();
+            }
+            else
+            {
+                shareStringPart = spreadSheet.WorkbookPart.AddNewPart<SharedStringTablePart>();
+            }
+
+            // Insert the text into the SharedStringTablePart.
+            int index = this.InsertSharedStringItem(text, shareStringPart);
+
+            // Grab the first worksheet created earlier.
+            WorksheetPart worksheetPart = spreadSheet.WorkbookPart.Workbook.WorkbookPart.WorksheetParts.First();
+
+            // Insert cell into the worksheet with the given column and row (iterator).
+            Cell cell = this.InsertCellInWorksheet(column, (uint)iterator, worksheetPart);
+
+            // Set the value of cell
+            cell.CellValue = new CellValue(index.ToString());
+            cell.DataType = new EnumValue<CellValues>(CellValues.SharedString);
+
+            // Save the new worksheet.
+            worksheetPart.Worksheet.Save();
+        }
+    }
+
+    // Given text and a SharedStringTablePart, creates a SharedStringItem with the specified text 
+    // and inserts it into the SharedStringTablePart. If the item already exists, returns its index.
+    private int InsertSharedStringItem(string text, SharedStringTablePart shareStringPart)
+    {
+        // If the part does not contain a SharedStringTable, create one.
+        if (shareStringPart.SharedStringTable == null)
+        {
+            shareStringPart.SharedStringTable = new SharedStringTable();
+        }
+
+        int i = 0;
+
+        // Iterate through all the items in the SharedStringTable. If the text already exists, return its index.
+        foreach (SharedStringItem item in shareStringPart.SharedStringTable.Elements<SharedStringItem>())
+        {
+            if (item.InnerText == text)
+            {
+                return i;
+            }
+
+            i++;
+        }
+
+        // The text does not exist in the part. Create the SharedStringItem and return its index.
+        shareStringPart.SharedStringTable.AppendChild(new SharedStringItem(new DocumentFormat.OpenXml.Spreadsheet.Text(text)));
+        shareStringPart.SharedStringTable.Save();
+
+        return i;
+    }
+
+    // Given a column name, a row index, and a WorksheetPart, inserts a cell into the worksheet. 
+    // If the cell already exists, returns it. 
+    private Cell InsertCellInWorksheet(string columnName, uint rowIndex, WorksheetPart worksheetPart)
     {
         Worksheet worksheet = worksheetPart.Worksheet;
         SheetData sheetData = worksheet.GetFirstChild<SheetData>();
         string cellReference = columnName + rowIndex;
 
+        // If the worksheet does not contain a row with the specified row index, insert one.
         Row row;
         if (sheetData.Elements<Row>().Where(r => r.RowIndex == rowIndex).Count() != 0)
         {
@@ -71,17 +135,33 @@ public class ExcelDataService : IDataService
         }
         else
         {
-            row = new Row() { RowIndex = ((uint)rowIndex) };
+            row = new Row() { RowIndex = rowIndex };
             sheetData.Append(row);
         }
 
-        Cell refCell = row.Descendants<Cell>().LastOrDefault();
+        // If there is not a cell with the specified column name, insert one.  
+        if (row.Elements<Cell>().Where(c => c.CellReference.Value == columnName + rowIndex).Count() > 0)
+        {
+            return row.Elements<Cell>().Where(c => c.CellReference.Value == cellReference).First();
+        }
+        else
+        {
+            // Cells must be in sequential order according to CellReference. Determine where to insert the new cell.
+            Cell refCell = null;
+            foreach (Cell cell in row.Elements<Cell>())
+            {
+                if (string.Compare(cell.CellReference.Value, cellReference, true) > 0)
+                {
+                    refCell = cell;
+                    break;
+                }
+            }
 
-        Cell newCell = new Cell() { CellReference = cellReference };
-        row.InsertAfter(newCell, refCell);
-
-        worksheet.Save();
-        return newCell;
+            Cell newCell = new Cell() { CellReference = cellReference };
+            row.InsertBefore(newCell, refCell);
 
+            worksheet.Save();
+            return newCell;
+        }
     }
 }