From fecb22d043de8ca4ecc8ab7dde4b3cf996e8e3fe Mon Sep 17 00:00:00 2001
From: Ari Sulistiono <ari.sulistiono@gmail.com>
Date: Tue, 8 Sep 2026 14:15:49 +0700
Subject: [PATCH] feat: integrate SCL FAT workspace into main tabs

---
 IntegratedFatWorkspaceControl.xaml            | 131 ++++++++++
 IntegratedFatWorkspaceControl.xaml.cs         | 237 ++++++++++++++++++
 MainWindow.IntegratedFatTab.cs                | 101 ++++++++
 MainWindow.IoTesting.cs                       |   9 +
 MainWindow.NavigationLayoutFix.cs             |  30 ++-
 MainWindow.WorkspaceModeSwitch.cs             |   7 +-
 MainWindow.xaml                               |  23 +-
 MainWindow.xaml.cs                            |  11 +-
 Models/IoTesting/IoSignalDisplayName.cs       |  42 +++-
 Models/IoTesting/IoTestModels.cs              |  18 +-
 SasOperationalUiPolicy.cs                     |   4 +-
 Services/IoTesting/IoFatReportScope.cs        |   5 +
 .../IoFatSignalDisplayNameFormatter.cs        |   2 +-
 .../IoTesting/IoFatV2ReportLayoutEngine.cs    |   2 +-
 ...rmAnnunciatorIntegrationRegressionTests.cs |  15 +-
 .../IntegratedFatWorkspaceRegressionTests.cs  |  68 +++++
 .../IoFatReportPreviewServiceTests.cs         |  30 ++-
 tests/ARSAS.Tests/IoSignalDisplayNameTests.cs |   6 +-
 .../MainWindowTopBarLayoutRegressionTests.cs  |   9 +-
 .../P0LatestFieldRegressionTests.cs           |  22 +-
 20 files changed, 718 insertions(+), 54 deletions(-)
 create mode 100644 IntegratedFatWorkspaceControl.xaml
 create mode 100644 IntegratedFatWorkspaceControl.xaml.cs
 create mode 100644 MainWindow.IntegratedFatTab.cs
 create mode 100644 tests/ARSAS.Tests/IntegratedFatWorkspaceRegressionTests.cs

diff --git a/IntegratedFatWorkspaceControl.xaml b/IntegratedFatWorkspaceControl.xaml
new file mode 100644
index 000000000..ca3c692f6
--- /dev/null
+++ b/IntegratedFatWorkspaceControl.xaml
@@ -0,0 +1,131 @@
+<UserControl x:Class="ArIED61850Tester.IntegratedFatWorkspaceControl"
+ xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+ xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+ <Grid>
+  <Grid x:Name="WorkspaceView">
+   <Grid.ColumnDefinitions>
+    <ColumnDefinition Width="230"/>
+    <ColumnDefinition Width="10"/>
+    <ColumnDefinition Width="*"/>
+   </Grid.ColumnDefinitions>
+   <Border Grid.Column="0" Style="{StaticResource WorkspaceCard}" Padding="10">
+    <DockPanel>
+     <StackPanel DockPanel.Dock="Top" Margin="2,1,2,9">
+      <TextBlock Text="FAT IED" Style="{StaticResource SectionTitle}"/>
+      <TextBlock Text="Shared SCL and live connection from Engineering" Style="{StaticResource Caption}" Margin="0,3,0,0" TextWrapping="Wrap"/>
+     </StackPanel>
+     <ListBox ItemsSource="{Binding EngineeringIeds}" SelectedItem="{Binding SelectedEngineeringIed, Mode=TwoWay}"
+              IsEnabled="{Binding Session.CanSelectIed}"
+              BorderThickness="0" Background="Transparent" HorizontalContentAlignment="Stretch"
+              ScrollViewer.HorizontalScrollBarVisibility="Disabled"
+              VirtualizingPanel.IsVirtualizing="True" VirtualizingPanel.VirtualizationMode="Recycling">
+      <ListBox.ItemTemplate>
+       <DataTemplate>
+        <Border Padding="9" Margin="0,0,0,7" Background="#F8FAFC" BorderBrush="#D8E1EE" BorderThickness="1" CornerRadius="10">
+         <Grid>
+          <Grid.ColumnDefinitions><ColumnDefinition Width="42"/><ColumnDefinition Width="*"/></Grid.ColumnDefinitions>
+          <Viewbox Width="38" Height="38">
+           <Control Width="50" Height="50" Template="{StaticResource IedRelayFrontPanelTemplate}">
+            <Control.Style>
+             <Style TargetType="Control">
+              <Setter Property="Foreground" Value="#EF4444"/>
+              <Style.Triggers>
+               <DataTrigger Binding="{Binding IsConnected}" Value="True">
+                <Setter Property="Foreground" Value="#20B26B"/>
+               </DataTrigger>
+              </Style.Triggers>
+             </Style>
+            </Control.Style>
+           </Control>
+          </Viewbox>
+          <StackPanel Grid.Column="1" Margin="7,0,0,0" VerticalAlignment="Center">
+           <TextBlock Text="{Binding Name}" FontSize="12" FontWeight="SemiBold" Foreground="{StaticResource Ink}" TextTrimming="CharacterEllipsis"/>
+           <TextBlock Text="{Binding EndpointText}" FontSize="9.8" Foreground="{StaticResource Muted}"/>
+           <TextBlock Text="{Binding ActivityText}" FontSize="9.2" FontWeight="SemiBold" Foreground="{StaticResource Accent}" Margin="0,2,0,0"/>
+          </StackPanel>
+         </Grid>
+        </Border>
+       </DataTemplate>
+      </ListBox.ItemTemplate>
+     </ListBox>
+    </DockPanel>
+   </Border>
+   <Border Grid.Column="2" Style="{StaticResource WorkspaceCard}" Padding="10">
+    <Grid>
+     <Grid.RowDefinitions><RowDefinition Height="Auto"/><RowDefinition Height="8"/><RowDefinition Height="*"/><RowDefinition Height="Auto"/></Grid.RowDefinitions>
+     <Grid>
+      <Grid.ColumnDefinitions><ColumnDefinition Width="*"/><ColumnDefinition Width="Auto"/></Grid.ColumnDefinitions>
+      <StackPanel>
+       <TextBlock Text="{Binding SelectedIed.IedName, StringFormat=FAT · {0}}" Style="{StaticResource WorkspaceTitle}"/>
+       <TextBlock Text="{Binding Session.StatusText}" Style="{StaticResource WorkspaceSubtitle}" Margin="0,2,0,0" TextTrimming="CharacterEllipsis"/>
+      </StackPanel>
+      <WrapPanel Grid.Column="1">
+       <Button Content="Start FAT" Style="{StaticResource PrimaryButton}" Click="StartFat_Click" Margin="0,0,6,0"
+               IsEnabled="{Binding Session.CanStart}"/>
+       <Button Content="Stop" Style="{StaticResource SoftButton}" Click="StopFat_Click" Margin="0,0,6,0"
+               IsEnabled="{Binding Session.CanStop}"/>
+       <Button Content="Value 1" Style="{StaticResource SoftButton}" Click="CaptureValue1_Click" Margin="0,0,6,0"/>
+       <Button Content="Value 2" Style="{StaticResource SoftButton}" Click="CaptureValue2_Click" Margin="0,0,6,0"/>
+       <Button Content="Print Preview" Style="{StaticResource SoftButton}" Click="OpenPreview_Click"/>
+      </WrapPanel>
+     </Grid>
+     <DataGrid x:Name="FatSignalsGrid" Grid.Row="2" ItemsSource="{Binding SelectedIed.TestPoints}"
+               AutoGenerateColumns="False" SelectionMode="Extended" SelectionUnit="FullRow"
+               Style="{StaticResource ModernDataGrid}" EnableRowVirtualization="True" EnableColumnVirtualization="True"
+               VirtualizingPanel.IsVirtualizing="True" VirtualizingPanel.VirtualizationMode="Recycling"
+               ScrollViewer.CanContentScroll="True" ScrollViewer.HorizontalScrollBarVisibility="Auto">
+      <DataGrid.Columns>
+       <DataGridCheckBoxColumn Header="TEST" Binding="{Binding TestEnabled, Mode=TwoWay}" Width="52"/>
+       <DataGridTextColumn Header="SIGNAL" Binding="{Binding DisplaySignalName}" Width="1.2*" MinWidth="145" IsReadOnly="True"/>
+       <DataGridTextColumn Header="IEC REFERENCE" Binding="{Binding ReportIecReference}" Width="1.65*" MinWidth="210" IsReadOnly="True"/>
+       <DataGridTextColumn Header="TYPE" Binding="{Binding SignalKind}" Width="74" IsReadOnly="True"/>
+       <DataGridTemplateColumn Header="LIVE VALUE" Width="108" IsReadOnly="True">
+        <DataGridTemplateColumn.CellTemplate><DataTemplate>
+         <StackPanel><TextBlock Text="{Binding Runtime.CurrentValue}" FontSize="11.8" FontWeight="SemiBold" Foreground="#1E3C64"/>
+          <TextBlock Text="{Binding Runtime.CurrentQuality}" FontSize="8.8" Foreground="#69798F"/></StackPanel>
+        </DataTemplate></DataGridTemplateColumn.CellTemplate>
+       </DataGridTemplateColumn>
+       <DataGridTemplateColumn Header="VALUE 1" Width="116" IsReadOnly="True">
+        <DataGridTemplateColumn.CellTemplate><DataTemplate>
+         <StackPanel><TextBlock Text="{Binding Value1Text}" FontSize="11.4" FontWeight="SemiBold"/>
+          <TextBlock Text="{Binding Value1RelayTimestampText}" FontSize="8.2" Foreground="#707E91"/></StackPanel>
+        </DataTemplate></DataGridTemplateColumn.CellTemplate>
+       </DataGridTemplateColumn>
+       <DataGridTemplateColumn Header="VALUE 2" Width="116" IsReadOnly="True">
+        <DataGridTemplateColumn.CellTemplate><DataTemplate>
+         <StackPanel><TextBlock Text="{Binding Value2Text}" FontSize="11.4" FontWeight="SemiBold"/>
+          <TextBlock Text="{Binding Value2RelayTimestampText}" FontSize="8.2" Foreground="#707E91"/></StackPanel>
+        </DataTemplate></DataGridTemplateColumn.CellTemplate>
+       </DataGridTemplateColumn>
+       <DataGridTextColumn Header="STATUS" Binding="{Binding FatStatusText}" Width="104" IsReadOnly="True"/>
+       <DataGridTextColumn Header="RESULT" Binding="{Binding FatResultText}" Width="98" IsReadOnly="True"/>
+      </DataGrid.Columns>
+     </DataGrid>
+     <Grid Grid.Row="3" Margin="0,8,0,0">
+      <Grid.ColumnDefinitions><ColumnDefinition Width="*"/><ColumnDefinition Width="Auto"/></Grid.ColumnDefinitions>
+      <TextBlock Text="{Binding StatusText}" Style="{StaticResource Caption}"/>
+      <TextBlock Grid.Column="1" Text="{Binding Session.ProgressText}" FontSize="10.5" FontWeight="SemiBold" Foreground="{StaticResource Accent}"/>
+     </Grid>
+    </Grid>
+   </Border>
+  </Grid>
+  <Border x:Name="PreviewView" Visibility="Collapsed" Style="{StaticResource WorkspaceCard}" Padding="0">
+   <Grid>
+    <Grid.RowDefinitions><RowDefinition Height="Auto"/><RowDefinition Height="*"/></Grid.RowDefinitions>
+    <Border Background="#F3F7FC" BorderBrush="#DDE6F2" BorderThickness="0,0,0,1" Padding="10,7">
+     <Grid>
+      <Grid.ColumnDefinitions><ColumnDefinition Width="*"/><ColumnDefinition Width="Auto"/></Grid.ColumnDefinitions>
+      <StackPanel Orientation="Horizontal">
+       <Button Content="← Back to FAT" Style="{StaticResource SoftButton}" Click="ClosePreview_Click" Margin="0,0,8,0"/>
+       <Button Content="Print" Style="{StaticResource PrimaryButton}" Click="PrintPreview_Click" Margin="0,0,8,0"/>
+       <Button Content="Refresh" Style="{StaticResource SoftButton}" Click="RefreshPreview_Click"/>
+      </StackPanel>
+      <TextBlock Grid.Column="1" Text="{Binding SelectedIed.IedName, StringFormat=Print Preview · {0}}" FontSize="11" FontWeight="SemiBold"
+                 Foreground="{StaticResource Muted}" VerticalAlignment="Center"/>
+     </Grid>
+    </Border>
+    <DocumentViewer x:Name="PreviewDocument" Grid.Row="1" Background="#EEF3F9" BorderThickness="0" ShowPageBorders="True"/>
+   </Grid>
+  </Border>
+ </Grid>
+</UserControl>
diff --git a/IntegratedFatWorkspaceControl.xaml.cs b/IntegratedFatWorkspaceControl.xaml.cs
new file mode 100644
index 000000000..63b6df0cb
--- /dev/null
+++ b/IntegratedFatWorkspaceControl.xaml.cs
@@ -0,0 +1,237 @@
+using System.ComponentModel;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Input;
+using System.Windows.Threading;
+using ArIED61850Tester.Models;
+using ArIED61850Tester.Models.IoTesting;
+using ArIED61850Tester.Services.IoTesting;
+
+namespace ArIED61850Tester;
+
+public partial class IntegratedFatWorkspaceControl : UserControl, INotifyPropertyChanged, IDisposable
+{
+    private readonly Action<Iec61850MonitorDevice?> _selectionChanged;
+    private IoTestIedPlan? _selectedIed;
+    private Iec61850MonitorDevice? _selectedEngineeringIed;
+    private string _statusText = "Select an IED and start FAT when its Engineering monitor is live.";
+    private bool _disposed;
+
+    public IntegratedFatWorkspaceControl(
+        IoTestWorkspaceLaunchResult launch,
+        IEnumerable<Iec61850MonitorDevice> engineeringIeds,
+        Action<Iec61850MonitorDevice?> selectionChanged)
+    {
+        InitializeComponent();
+        Project = launch.Project;
+        Session = launch.Session;
+        Storage = launch.Workspace;
+        EngineeringIeds = engineeringIeds;
+        _selectionChanged = selectionChanged;
+        Session.PropertyChanged += Session_PropertyChanged;
+        DataContext = this;
+        SelectedEngineeringIed = EngineeringIeds.FirstOrDefault();
+        SelectedIed ??= Project.Ieds.FirstOrDefault();
+    }
+
+    public IoTestProject Project { get; }
+    public IoTestSessionController Session { get; }
+    public IoTestWorkspacePersistence Storage { get; }
+    public IEnumerable<Iec61850MonitorDevice> EngineeringIeds { get; }
+
+    public Iec61850MonitorDevice? SelectedEngineeringIed
+    {
+        get => _selectedEngineeringIed;
+        set
+        {
+            if (ReferenceEquals(_selectedEngineeringIed, value)) return;
+            _selectedEngineeringIed = value;
+            Raise(nameof(SelectedEngineeringIed));
+            SelectedIed = ResolveFatIed(value);
+            _selectionChanged(value);
+        }
+    }
+
+    public IoTestIedPlan? SelectedIed
+    {
+        get => _selectedIed;
+        set
+        {
+            if (ReferenceEquals(_selectedIed, value)) return;
+            _selectedIed = value;
+            Raise(nameof(SelectedIed));
+            ApplyPointScope();
+            if (PreviewView.Visibility == Visibility.Visible) RefreshPreview();
+        }
+    }
+
+    public string StatusText
+    {
+        get => _statusText;
+        private set
+        {
+            if (_statusText == value) return;
+            _statusText = value;
+            Raise(nameof(StatusText));
+        }
+    }
+
+    public event PropertyChangedEventHandler? PropertyChanged;
+
+    public void SelectEngineeringIed(string? deviceId, string? name, string? ipAddress)
+    {
+        if (!Session.CanSelectIed)
+            return;
+
+        var match = Project.Ieds.FirstOrDefault(ied =>
+                        !string.IsNullOrWhiteSpace(deviceId) &&
+                        ied.LiveDeviceId.Equals(deviceId, StringComparison.OrdinalIgnoreCase))
+                    ?? Project.Ieds.FirstOrDefault(ied =>
+                        ied.IedName.Equals(name, StringComparison.OrdinalIgnoreCase) &&
+                        (string.IsNullOrWhiteSpace(ipAddress) ||
+                         ied.IpAddress.Equals(ipAddress, StringComparison.OrdinalIgnoreCase)));
+        var engineeringMatch = EngineeringIeds.FirstOrDefault(ied =>
+                                   !string.IsNullOrWhiteSpace(deviceId) &&
+                                   ied.DeviceId.Equals(deviceId, StringComparison.OrdinalIgnoreCase))
+                               ?? EngineeringIeds.FirstOrDefault(ied =>
+                                   ied.Name.Equals(name, StringComparison.OrdinalIgnoreCase) &&
+                                   (string.IsNullOrWhiteSpace(ipAddress) ||
+                                    ied.IpAddress.Equals(ipAddress, StringComparison.OrdinalIgnoreCase)));
+        if (engineeringMatch != null)
+            SelectedEngineeringIed = engineeringMatch;
+        else if (match != null)
+            SelectedIed = match;
+    }
+
+    private IoTestIedPlan? ResolveFatIed(Iec61850MonitorDevice? device)
+        => device == null
+            ? null
+            : Project.Ieds.FirstOrDefault(ied =>
+                  ied.LiveDeviceId.Equals(device.DeviceId, StringComparison.OrdinalIgnoreCase))
+              ?? Project.Ieds.FirstOrDefault(ied =>
+                  ied.IedName.Equals(device.Name, StringComparison.OrdinalIgnoreCase) &&
+                  ied.IpAddress.Equals(device.IpAddress, StringComparison.OrdinalIgnoreCase));
+
+    private void ApplyPointScope()
+    {
+        if (SelectedIed == null) return;
+        var view = CollectionViewSource.GetDefaultView(SelectedIed.TestPoints);
+        view.Filter = item => item is IoTestPointPlan point &&
+                              point.WorkspaceSelected && point.IsIncludedInFat;
+        view.Refresh();
+    }
+
+    private void StartFat_Click(object sender, RoutedEventArgs e)
+        => ShowResult(Session.Start(SelectedIed));
+
+    private void StopFat_Click(object sender, RoutedEventArgs e)
+        => ShowResult(Session.Stop("Stopped from integrated FAT tab."));
+
+    private void CaptureValue1_Click(object sender, RoutedEventArgs e)
+        => CaptureSelected(FatValueSlot.Value1);
+
+    private void CaptureValue2_Click(object sender, RoutedEventArgs e)
+        => CaptureSelected(FatValueSlot.Value2);
+
+    private void CaptureSelected(FatValueSlot slot)
+    {
+        var points = FatSignalsGrid.SelectedItems.OfType<IoTestPointPlan>().ToArray();
+        if (points.Length == 0 && FatSignalsGrid.SelectedItem is IoTestPointPlan current)
+            points = new[] { current };
+        if (points.Length == 0)
+        {
+            StatusText = "Select at least one FAT row first.";
+            return;
+        }
+
+        var failures = new List<string>();
+        foreach (var point in points)
+        {
+            var result = Session.CaptureOperatorSnapshot(point, slot);
+            if (!result.Succeeded)
+                failures.Add($"{point.DisplaySignalName}: {result.Message}");
+        }
+        Storage.ScheduleSave();
+        StatusText = failures.Count == 0
+            ? $"{slot}: captured for {points.Length} selected signal(s)."
+            : string.Join(" • ", failures.Take(3));
+    }
+
+    private void ShowResult(IoTestSessionActionResult result)
+    {
+        StatusText = result.Message;
+        if (result.Succeeded)
+            Storage.ScheduleSave();
+    }
+
+    private void OpenPreview_Click(object sender, RoutedEventArgs e)
+    {
+        if (SelectedIed == null)
+        {
+            StatusText = "Select an IED before opening Print Preview.";
+            return;
+        }
+        WorkspaceView.Visibility = Visibility.Collapsed;
+        PreviewView.Visibility = Visibility.Visible;
+        RefreshPreview();
+    }
+
+    private void ClosePreview_Click(object sender, RoutedEventArgs e)
+    {
+        PreviewView.Visibility = Visibility.Collapsed;
+        WorkspaceView.Visibility = Visibility.Visible;
+    }
+
+    private void RefreshPreview_Click(object sender, RoutedEventArgs e)
+        => RefreshPreview();
+
+    private void RefreshPreview()
+    {
+        if (SelectedIed == null)
+            return;
+        try
+        {
+            var scoped = IoFatReportPreviewService.CreateIedScopedProject(Project, SelectedIed);
+            var draft = Session.IsSessionActive && ReferenceEquals(Session.ActiveIed, SelectedIed);
+            PreviewDocument.Document = IoFatReportPreviewDocumentBuilder.Build(scoped, draft);
+            PreviewDocument.UpdateLayout();
+            Dispatcher.BeginInvoke(new Action(PreviewDocument.FitToWidth), DispatcherPriority.Loaded);
+        }
+        catch (Exception ex)
+        {
+            StatusText = $"Print Preview could not be rendered: {ex.Message}";
+        }
+    }
+
+    private void PrintPreview_Click(object sender, RoutedEventArgs e)
+    {
+        if (PreviewDocument.Document != null &&
+            ApplicationCommands.Print.CanExecute(null, PreviewDocument))
+        {
+            ApplicationCommands.Print.Execute(null, PreviewDocument);
+        }
+    }
+
+    private void Session_PropertyChanged(object? sender, PropertyChangedEventArgs e)
+    {
+        Raise(nameof(Session));
+        if (PreviewView.Visibility == Visibility.Visible &&
+            e.PropertyName is nameof(IoTestSessionController.State) or
+                nameof(IoTestSessionController.EvidenceRecordCount))
+        {
+            Dispatcher.BeginInvoke(new Action(RefreshPreview), DispatcherPriority.Background);
+        }
+    }
+
+    private void Raise(string propertyName)
+        => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+
+    public void Dispose()
+    {
+        if (_disposed) return;
+        _disposed = true;
+        Session.PropertyChanged -= Session_PropertyChanged;
+        Storage.ScheduleSave();
+    }
+}
diff --git a/MainWindow.IntegratedFatTab.cs b/MainWindow.IntegratedFatTab.cs
new file mode 100644
index 000000000..8e100fd3c
--- /dev/null
+++ b/MainWindow.IntegratedFatTab.cs
@@ -0,0 +1,101 @@
+using System.Windows;
+using ArIED61850Tester.Models;
+using ArIED61850Tester.Models.IoTesting;
+using ArIED61850Tester.Services.IoTesting;
+
+namespace ArIED61850Tester;
+
+public partial class MainWindow
+{
+    private IntegratedFatWorkspaceControl? _integratedFatWorkspace;
+    private IoTestWorkspaceLaunchResult? _integratedFatLaunch;
+
+    private async void OpenIntegratedFatFromCurrentScl_Click(object sender, RoutedEventArgs e)
+    {
+        if (_integratedFatWorkspace != null)
+        {
+            MainTabs.SelectedIndex = 6;
+            return;
+        }
+
+        var sources = CurrentEngineeringSclSourcePaths();
+        if (sources.Length == 0)
+        {
+            SetStatus("Open an SCL in IEC 61850 Explorer before entering FAT.");
+            MessageBox.Show(
+                this,
+                "The integrated FAT tab uses only the SCL currently open in Engineering. Open an SCL first.",
+                "No active Engineering SCL",
+                MessageBoxButton.OK,
+                MessageBoxImage.Information);
+            MainTabs.SelectedIndex = 0;
+            return;
+        }
+
+        await OpenSclFatSourcesAsync(sources, selectionMode: null);
+    }
+
+    private void ShowIntegratedFatWorkspace(IoTestWorkspaceLaunchResult launch)
+    {
+        _integratedFatLaunch = launch;
+        _activeIoTestSessionController = launch.Session;
+        Interlocked.Exchange(ref _ioTestObservationSequence, DateTime.UtcNow.Ticks);
+        _runtime.PointUpdated += Runtime_IoTestPointUpdated;
+
+        var engineeringIeds = Devices.Where(device => launch.Project.Ieds.Any(ied =>
+            ied.LiveDeviceId.Equals(device.DeviceId, StringComparison.OrdinalIgnoreCase) ||
+            (ied.IedName.Equals(device.Name, StringComparison.OrdinalIgnoreCase) &&
+             ied.IpAddress.Equals(device.IpAddress, StringComparison.OrdinalIgnoreCase))));
+
+        _integratedFatWorkspace = new IntegratedFatWorkspaceControl(
+            launch,
+            engineeringIeds,
+            selected => SynchronizeIntegratedFatSelection(selected));
+        IntegratedFatHost.Children.Clear();
+        IntegratedFatHost.Children.Add(_integratedFatWorkspace);
+        if (SelectedDevice != null)
+        {
+            _integratedFatWorkspace.SelectEngineeringIed(
+                SelectedDevice.DeviceId,
+                SelectedDevice.Name,
+                SelectedDevice.IpAddress);
+        }
+
+        MainTabs.SelectedIndex = 6;
+        SetStatus($"Integrated FAT ready · {launch.Project.Ieds.Count} IED · shared Engineering live process image.");
+        UpdateIoFatWorkspaceModeState();
+    }
+
+    private void SynchronizeIntegratedFatSelection(Iec61850MonitorDevice? selected)
+    {
+        if (selected == null) return;
+        if (!ReferenceEquals(SelectedDevice, selected))
+            SelectedDevice = selected;
+    }
+
+    private void DisposeIntegratedFatWorkspace()
+    {
+        var launch = _integratedFatLaunch;
+        if (launch == null) return;
+
+        _runtime.PointUpdated -= Runtime_IoTestPointUpdated;
+        if (launch.Session.IsSessionActive)
+            launch.Session.Stop("Integrated FAT workspace closed.");
+        _integratedFatWorkspace?.Dispose();
+        DetachIoFatSelectionBridge(launch.Project);
+        launch.Session.Dispose();
+        launch.Workspace.Dispose();
+        if (ReferenceEquals(_activeIoTestSessionController, launch.Session))
+            _activeIoTestSessionController = null;
+
+        _integratedFatWorkspace = null;
+        _integratedFatLaunch = null;
+        if (IntegratedFatHost != null)
+            IntegratedFatHost.Children.Clear();
+        if (_pollingIntervalBeforeIoFat.HasValue)
+        {
+            PollingIntervalMs = _pollingIntervalBeforeIoFat.Value;
+            _pollingIntervalBeforeIoFat = null;
+        }
+    }
+}
diff --git a/MainWindow.IoTesting.cs b/MainWindow.IoTesting.cs
index 52f1cfc91..bda203978 100644
--- a/MainWindow.IoTesting.cs
+++ b/MainWindow.IoTesting.cs
@@ -471,6 +471,7 @@ private async void OpenIoListPackage_Click(object sender, RoutedEventArgs e)
 
     private Task ShowIoTestingWorkspaceAsync(IoTestWorkspaceLaunchResult launch, int importWarningCount)
     {
+        DisposeIntegratedFatWorkspace();
         AttachIoFatSelectionBridge(launch.Project);
         var binding = _ioTestLiveBindingService.Bind(launch.Project, Devices);
         var restoredText = launch.RestoredProgress ? "saved progress restored" : "new project";
@@ -491,6 +492,14 @@ private Task ShowIoTestingWorkspaceAsync(IoTestWorkspaceLaunchResult launch, int
         _pollingIntervalBeforeIoFat ??= PollingIntervalMs;
         PollingIntervalMs = Math.Min(PollingIntervalMs, IoFatPollingIntervalMs);
 
+        if (launch.Project.Sources.Count > 0 &&
+            launch.Project.Sources.All(source =>
+                source.Kind.Equals(IoFatSourceKinds.Scl, StringComparison.OrdinalIgnoreCase)))
+        {
+            ShowIntegratedFatWorkspace(launch);
+            return Task.CompletedTask;
+        }
+
         var controller = launch.Session;
         var persistence = launch.Workspace;
         var window = new IoListTestingWindow(launch.Project, controller, persistence) { Owner = this };
diff --git a/MainWindow.NavigationLayoutFix.cs b/MainWindow.NavigationLayoutFix.cs
index fe2e8325f..9010f108a 100644
--- a/MainWindow.NavigationLayoutFix.cs
+++ b/MainWindow.NavigationLayoutFix.cs
@@ -10,11 +10,11 @@ namespace ArIED61850Tester;
 /// <summary>
 /// Owns the responsive geometry of the MainWindow workflow header.
 ///
-/// The original XAML used a 760 px shell split into six equal columns while the
+/// The original XAML used a 760 px shell split into equal columns while the
 /// selection pill moved in hard-coded 150 px steps. That was barely large enough for
 /// short labels and clipped "IEC 61850 Explorer" / "GOOSE Subscriber" once the center
 /// workspace switch and live connection/status chips were also present. This behavior
-/// keeps the header single-line at normal desktop sizes, deliberately compacts labels
+/// keeps all seven destinations on one line at normal desktop sizes, deliberately compacts labels
 /// at smaller widths, and derives the selection pill from the real nav cell width.
 /// </summary>
 internal static class MainWindowNavigationLayoutFix
@@ -31,7 +31,9 @@ internal static class MainWindowNavigationLayoutFix
         "Live Monitor",
         "Event Log",
         "Alarm",
-        "GOOSE Subscriber"
+        "GOOSE Subscriber",
+        "Diagnostics",
+        "FAT"
     ];
 
     private static readonly string[] CompactLabels =
@@ -40,7 +42,9 @@ internal static class MainWindowNavigationLayoutFix
         "Live",
         "Events",
         "Alarm",
-        "GOOSE"
+        "GOOSE",
+        "Diagnostics",
+        "FAT"
     ];
 
     [ModuleInitializer]
@@ -93,7 +97,7 @@ private static void OnMainWindowButtonClick(object sender, RoutedEventArgs e)
         if (sender is not MainWindow window || e.Source is not Button button)
             return;
 
-        if (button.Name is not ("NavExplorerButton" or "NavLiveButton" or "NavEventsButton" or "NavAlarmButton" or "NavGooseButton" or "NavDiagnosticsButton"))
+        if (button.Name is not ("NavExplorerButton" or "NavLiveButton" or "NavEventsButton" or "NavAlarmButton" or "NavGooseButton" or "NavDiagnosticsButton" or "NavFatButton"))
             return;
 
         // A repeated click on the already-selected tab does not raise SelectionChanged,
@@ -169,7 +173,10 @@ private static void ApplyResponsiveLayout(MainWindow window)
             // Diagnostics owns a StackPanel containing its text plus the red alert
             // badge. Never replace that Content tree while changing layout density.
             if (index < labels.Length)
-                button.Content = labels[index];
+            {
+                if (index != 5)
+                    button.Content = labels[index];
+            }
 
             button.MinHeight = 40;
             button.MinWidth = 0;
@@ -195,7 +202,8 @@ private static void ApplyResponsiveLayout(MainWindow window)
             window.FindName("NavEventsButton") as Button,
             window.FindName("NavAlarmButton") as Button,
             window.FindName("NavGooseButton") as Button,
-            window.FindName("NavDiagnosticsButton") as Button
+            window.FindName("NavDiagnosticsButton") as Button,
+            window.FindName("NavFatButton") as Button
         ];
 
     private static void UpdatePillGeometry(MainWindow window, double shellWidth)
@@ -204,9 +212,9 @@ private static void UpdatePillGeometry(MainWindow window, double shellWidth)
             return;
 
         // Border padding owns 10 px horizontally. The nav grid itself is divided into
-        // six equal star columns, so this is the exact width used by each button cell.
+        // seven equal star columns, so this is the exact width used by each button cell.
         var contentWidth = Math.Max(0d, shellWidth - 10d);
-        var cellWidth = contentWidth / 6d;
+        var cellWidth = contentWidth / 7d;
         pill.Width = Math.Max(1d, cellWidth - 2d);
         pill.Height = 36;
         pill.HorizontalAlignment = HorizontalAlignment.Left;
@@ -279,8 +287,8 @@ private static void PositionPill(MainWindow window, bool animate)
         if (contentWidth <= 0d)
             contentWidth = Math.Max(0d, shell.Width - shell.Padding.Left - shell.Padding.Right);
 
-        var cellWidth = contentWidth / 6d;
-        var target = Math.Clamp(tabs.SelectedIndex, 0, 5) * cellWidth;
+        var cellWidth = contentWidth / 7d;
+        var target = Math.Clamp(tabs.SelectedIndex, 0, 6) * cellWidth;
         pill.Width = Math.Max(1d, cellWidth - 2d);
 
         translate.BeginAnimation(TranslateTransform.XProperty, null);
diff --git a/MainWindow.WorkspaceModeSwitch.cs b/MainWindow.WorkspaceModeSwitch.cs
index 71983c289..20d3551fb 100644
--- a/MainWindow.WorkspaceModeSwitch.cs
+++ b/MainWindow.WorkspaceModeSwitch.cs
@@ -138,6 +138,11 @@ internal void ShowEngineeringWorkspaceFromFat(IoListTestingWindow window)
 
     private async void OpenOrResumeIoFatWorkspace_Click(object sender, RoutedEventArgs e)
     {
+        if (_integratedFatWorkspace != null)
+        {
+            MainTabs.SelectedIndex = 6;
+            return;
+        }
         if (ShowLoadedIoFatWorkspace())
             return;
 
@@ -285,7 +290,7 @@ private void UpdateIoFatWorkspaceModeState()
         if (_workspaceFatButton == null)
             return;
 
-        var loaded = _loadedIoFatWindow is { IsLoaded: true };
+        var loaded = _integratedFatWorkspace != null || _loadedIoFatWindow is { IsLoaded: true };
         _workspaceFatButton.Content = loaded ? "IO LIST FAT · LOADED" : "IO LIST FAT";
         _workspaceFatButton.ToolTip = loaded
             ? "Return instantly to the loaded IO List FAT workspace"
diff --git a/MainWindow.xaml b/MainWindow.xaml
index 205519e97..196534a1d 100644
--- a/MainWindow.xaml
+++ b/MainWindow.xaml
@@ -121,8 +121,9 @@
                         <ColumnDefinition Width="*"/>
                         <ColumnDefinition Width="*"/>
                         <ColumnDefinition Width="*"/>
+                        <ColumnDefinition Width="*"/>
                     </Grid.ColumnDefinitions>
-                    <Border x:Name="WorkflowPill" Grid.ColumnSpan="6" Width="148" Height="34"
+                    <Border x:Name="WorkflowPill" Grid.ColumnSpan="7" Width="126" Height="34"
                             HorizontalAlignment="Left" VerticalAlignment="Center" CornerRadius="17"
                             Background="{StaticResource Accent}" RenderTransformOrigin="0.5,0.5">
                         <Border.RenderTransform>
@@ -151,12 +152,14 @@
                             </Border>
                         </StackPanel>
                     </Button>
+                    <Button x:Name="NavFatButton" Grid.Column="6" Content="FAT" Tag="6"
+                            Click="NavButton_Click" Style="{StaticResource SegmentedNavButton}"/>
                 </Grid>
             </Border>
 
             <!-- Runtime counts intentionally live only in the bottom status bar.
                  Keeping the header free of duplicate status chips reduces visual noise
-                 and reserves width for the six workflow destinations. -->
+                 and reserves width for the seven workflow destinations. -->
         </Grid>
 
         <TabControl x:Name="MainTabs" Grid.Row="1" SelectedIndex="0"
@@ -1683,6 +1686,22 @@
                         </DataGrid>
                     </DockPanel>
                 </Border>
+            </TabItem>
+            <TabItem Header="FAT">
+                <Grid x:Name="IntegratedFatHost">
+                    <Border Style="{StaticResource WorkspaceCard}" Padding="22"
+                            HorizontalAlignment="Center" VerticalAlignment="Center" MaxWidth="560">
+                        <StackPanel>
+                            <TextBlock Text="FAT uses the active Engineering SCL" Style="{StaticResource WorkspaceTitle}"
+                                       HorizontalAlignment="Center"/>
+                            <TextBlock Text="Open an SCL in IEC 61850 Explorer first. The FAT tab will reuse its IED model, connection, selected signals and live values without opening another window."
+                                       Style="{StaticResource WorkspaceSubtitle}" TextWrapping="Wrap"
+                                       TextAlignment="Center" Margin="0,8,0,14"/>
+                            <Button Content="Build FAT from current SCL" Style="{StaticResource PrimaryButton}"
+                                    HorizontalAlignment="Center" Click="OpenIntegratedFatFromCurrentScl_Click"/>
+                        </StackPanel>
+                    </Border>
+                </Grid>
             </TabItem>
                 </TabControl>
 
diff --git a/MainWindow.xaml.cs b/MainWindow.xaml.cs
index 4f55a7528..6d6ea08e5 100644
--- a/MainWindow.xaml.cs
+++ b/MainWindow.xaml.cs
@@ -89,6 +89,10 @@ public Iec61850MonitorDevice? SelectedDevice
             RaiseWorkspaceCounts();
             TryAutoExpandCommandPanelOnce(_selectedDevice);
             ApplyExplorerLiveSearchFilter();
+            _integratedFatWorkspace?.SelectEngineeringIed(
+                _selectedDevice?.DeviceId,
+                _selectedDevice?.Name,
+                _selectedDevice?.IpAddress);
             // ctlModel inspection is preloaded independently of the Expander. Avoid
             // changing the row set after the panel's first frame has already painted.
         }
@@ -620,7 +624,7 @@ private void NavButton_Click(object sender, RoutedEventArgs e)
     {
         if (sender is not Button button || !int.TryParse(button.Tag?.ToString(), out var index))
             return;
-        index = Math.Clamp(index, 0, 5);
+        index = Math.Clamp(index, 0, 6);
         MainTabs.SelectedIndex = index;
         UpdateNavigationVisuals(index, animate: true);
     }
@@ -654,7 +658,7 @@ private void UpdateNavigationVisuals(int index, bool animate)
         if (WorkflowPillTranslate == null)
             return;
 
-        var target = Math.Clamp(index, 0, 5) * 150d;
+        var target = Math.Clamp(index, 0, 6) * 128d;
         if (animate)
         {
             var animation = new DoubleAnimation(target, TimeSpan.FromMilliseconds(190))
@@ -669,7 +673,7 @@ private void UpdateNavigationVisuals(int index, bool animate)
             WorkflowPillTranslate.X = target;
         }
 
-        var buttons = new[] { NavExplorerButton, NavLiveButton, NavEventsButton, NavAlarmButton, NavGooseButton, NavDiagnosticsButton };
+        var buttons = new[] { NavExplorerButton, NavLiveButton, NavEventsButton, NavAlarmButton, NavGooseButton, NavDiagnosticsButton, NavFatButton };
         for (var i = 0; i < buttons.Length; i++)
             buttons[i].Foreground = i == index ? Brushes.White : new SolidColorBrush(Color.FromRgb(71, 84, 103));
     }
@@ -2268,6 +2272,7 @@ private async Task ShutdownApplicationAsync()
         {
             _uiFlushTimer.Stop();
             _progressAnimationTimer.Stop();
+            DisposeIntegratedFatWorkspace();
 
             foreach (var device in Devices)
             {
diff --git a/Models/IoTesting/IoSignalDisplayName.cs b/Models/IoTesting/IoSignalDisplayName.cs
index e0130642f..a48a2a097 100644
--- a/Models/IoTesting/IoSignalDisplayName.cs
+++ b/Models/IoTesting/IoSignalDisplayName.cs
@@ -16,21 +16,29 @@ public static string Format(string? signalName, string? iecReference)
     {
         var name = string.IsNullOrWhiteSpace(signalName) ? "Signal" : signalName.Trim();
         var reference = iecReference?.Trim() ?? string.Empty;
-
         var phaseMatch = PhaseToken().Match(reference);
         if (phaseMatch.Success)
         {
             var phase = phaseMatch.Groups["phase"].Value.ToUpperInvariant();
-            var suffix = $"Phs{phase}";
-            if (name.EndsWith($" {suffix}", StringComparison.OrdinalIgnoreCase))
-                return name;
+            if (phase.Length == 1 &&
+                name.Equals($"Thd{phase}", StringComparison.OrdinalIgnoreCase))
+            {
+                name = "Thd";
+            }
+
+            var suffix = $"Phs {phase}";
+            if (name.EndsWith($" {suffix}", StringComparison.OrdinalIgnoreCase) ||
+                name.EndsWith($" Phs{phase}", StringComparison.OrdinalIgnoreCase))
+            {
+                return $"{name[..name.LastIndexOf(' ')]} {suffix}";
+            }
 
             return $"{name} {suffix}";
         }
 
-        if (TryExtractLogicalNodeContext(reference, out var logicalNodeClass, out var dataObject)
-            && RequiresLogicalNodeOwner(dataObject)
-            && name.Equals(dataObject, StringComparison.OrdinalIgnoreCase))
+        if (TryExtractLogicalNodeContext(reference, out var logicalNodeClass, out var dataObject) &&
+            RequiresLogicalNodeOwner(dataObject) &&
+            name.Equals(dataObject, StringComparison.OrdinalIgnoreCase))
         {
             return $"{logicalNodeClass} {name}";
         }
@@ -38,6 +46,20 @@ public static string Format(string? signalName, string? iecReference)
         return name;
     }
 
+    /// <summary>
+    /// Formats from the first candidate that still carries an IEC phase token. Runtime,
+    /// event-log and report identities are allowed to differ, but presentation must not
+    /// silently fall back to a DO-only name such as A/A/A when any canonical identity still
+    /// proves phsA/phsB/phsC or a phase-to-phase branch.
+    /// </summary>
+    public static string FormatFromCandidates(string? signalName, params string?[] references)
+    {
+        references ??= Array.Empty<string?>();
+        var phaseReference = references.FirstOrDefault(reference =>
+            !string.IsNullOrWhiteSpace(reference) && PhaseToken().IsMatch(reference));
+        return Format(signalName, phaseReference ?? references.FirstOrDefault());
+    }
+
     private static bool TryExtractLogicalNodeContext(
         string reference,
         out string logicalNodeClass,
@@ -45,7 +67,6 @@ private static bool TryExtractLogicalNodeContext(
     {
         logicalNodeClass = string.Empty;
         dataObject = string.Empty;
-
         if (string.IsNullOrWhiteSpace(reference))
             return false;
 
@@ -53,7 +74,6 @@ private static bool TryExtractLogicalNodeContext(
         var tail = slashIndex >= 0 && slashIndex + 1 < reference.Length
             ? reference[(slashIndex + 1)..]
             : reference;
-
         var dotIndex = tail.IndexOf('.');
         var dollarIndex = tail.IndexOf('$');
         var separatorIndex = dotIndex switch
@@ -62,7 +82,6 @@ private static bool TryExtractLogicalNodeContext(
             >= 0 => dotIndex,
             _ => dollarIndex
         };
-
         if (separatorIndex <= 0 || separatorIndex + 1 >= tail.Length)
             return false;
 
@@ -77,11 +96,9 @@ private static bool TryExtractLogicalNodeContext(
             var tokens = remainder.Split('$', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
             if (tokens.Length == 0)
                 return false;
-
             var dataObjectIndex = IsFunctionalConstraint(tokens[0]) ? 1 : 0;
             if (dataObjectIndex >= tokens.Length)
                 return false;
-
             dataObject = NormalizeDataObjectToken(tokens[dataObjectIndex]);
         }
         else
@@ -110,7 +127,6 @@ private static bool TryExtractLogicalNodeClass(string logicalNodeToken, out stri
         var end = token.Length;
         while (end > 0 && char.IsDigit(token[end - 1]))
             end--;
-
         if (end == 0)
             return false;
 
diff --git a/Models/IoTesting/IoTestModels.cs b/Models/IoTesting/IoTestModels.cs
index cc6afbbfd..aea888119 100644
--- a/Models/IoTesting/IoTestModels.cs
+++ b/Models/IoTesting/IoTestModels.cs
@@ -493,7 +493,23 @@ private set
 
     public string LiveBindingReason { get => _liveBindingReason; private set => Set(ref _liveBindingReason, value ?? string.Empty); }
     public string LiveDeviceId { get => _liveDeviceId; private set => Set(ref _liveDeviceId, value ?? string.Empty); }
-    public string LiveSignalReference { get => _liveSignalReference; private set => Set(ref _liveSignalReference, value ?? string.Empty); }
+    public string LiveSignalReference
+    {
+        get => _liveSignalReference;
+        private set
+        {
+            if (Set(ref _liveSignalReference, value ?? string.Empty))
+                Raise(nameof(DisplaySignalName));
+        }
+    }
+    [JsonIgnore]
+    public string DisplaySignalName => IoSignalDisplayName.FormatFromCandidates(
+        SignalName,
+        LiveSignalReference,
+        EventLogSearchReference,
+        SourceIecReference,
+        ReportDisplayReference,
+        ObjectReference);
     public bool IsLiveBound => LiveBindingState is IoTestLiveBindingState.BoundExact or IoTestLiveBindingState.BoundNormalized or IoTestLiveBindingState.LivePointReady;
     public string LiveBindingText => LiveBindingState switch
     {
diff --git a/SasOperationalUiPolicy.cs b/SasOperationalUiPolicy.cs
index cd9cd10d7..a095e8fa0 100644
--- a/SasOperationalUiPolicy.cs
+++ b/SasOperationalUiPolicy.cs
@@ -24,7 +24,7 @@ internal static class SasOperationalUiPolicy
     private static readonly ConditionalWeakTable<object, object> FilteredViews = new();
     private static readonly string[] NavigationButtonNames =
     {
-        "NavExplorerButton", "NavLiveButton", "NavEventsButton", "NavAlarmButton", "NavGooseButton", "NavDiagnosticsButton"
+        "NavExplorerButton", "NavLiveButton", "NavEventsButton", "NavAlarmButton", "NavGooseButton", "NavDiagnosticsButton", "NavFatButton"
     };
 
     [ModuleInitializer]
@@ -267,4 +267,4 @@ private static LinearGradientBrush AccentGradient()
         brush.Freeze();
         return brush;
     }
-}
\ No newline at end of file
+}
diff --git a/Services/IoTesting/IoFatReportScope.cs b/Services/IoTesting/IoFatReportScope.cs
index 875bce98b..bc4c75144 100644
--- a/Services/IoTesting/IoFatReportScope.cs
+++ b/Services/IoTesting/IoFatReportScope.cs
@@ -150,6 +150,11 @@ private static IoTestPointPlan ClonePoint(IoTestPointPlan source)
             BindingStatus = source.BindingStatus,
             BindingEvidence = source.BindingEvidence
         };
+        clone.ApplyLiveBinding(
+            source.LiveBindingState,
+            source.LiveBindingReason,
+            source.LiveDeviceId,
+            source.LiveSignalReference);
         clone.RestoreFatDisposition(source.FatDisposition);
         CloneRuntime(source.Runtime, clone.Runtime);
         return clone;
diff --git a/Services/IoTesting/IoFatSignalDisplayNameFormatter.cs b/Services/IoTesting/IoFatSignalDisplayNameFormatter.cs
index 4be48bb91..c2fc02879 100644
--- a/Services/IoTesting/IoFatSignalDisplayNameFormatter.cs
+++ b/Services/IoTesting/IoFatSignalDisplayNameFormatter.cs
@@ -12,7 +12,7 @@ public static class IoFatSignalDisplayNameFormatter
     public static string Format(IoTestPointPlan point)
     {
         ArgumentNullException.ThrowIfNull(point);
-        return IoSignalDisplayName.Format(point.SignalName, point.ReportIecReference);
+        return point.DisplaySignalName;
     }
 
     public static string Format(string? signalName, string? iecReference)
diff --git a/Services/IoTesting/IoFatV2ReportLayoutEngine.cs b/Services/IoTesting/IoFatV2ReportLayoutEngine.cs
index 90e50a4e8..40296dcb6 100644
--- a/Services/IoTesting/IoFatV2ReportLayoutEngine.cs
+++ b/Services/IoTesting/IoFatV2ReportLayoutEngine.cs
@@ -189,7 +189,7 @@ private static void DrawPointRow(
         var cells = new[]
         {
             rowNumber.ToString(),
-            Short(IoSignalDisplayName.Format(point.SignalName, point.ReportIecReference), 26),
+            Short(point.DisplaySignalName, 26),
             string.Empty,
             point.SignalKind.ToString(),
             ValueCell(point, FatValueSlot.Value1),
diff --git a/tests/ARSAS.Tests/AlarmAnnunciatorIntegrationRegressionTests.cs b/tests/ARSAS.Tests/AlarmAnnunciatorIntegrationRegressionTests.cs
index f7811ae2f..1e0411a0e 100644
--- a/tests/ARSAS.Tests/AlarmAnnunciatorIntegrationRegressionTests.cs
+++ b/tests/ARSAS.Tests/AlarmAnnunciatorIntegrationRegressionTests.cs
@@ -5,7 +5,7 @@ namespace ARSAS.Tests;
 public sealed class AlarmAnnunciatorIntegrationRegressionTests
 {
     [Fact]
-    public void Header_UsesSixWorkflowDestinations_WithoutDuplicateRuntimeStatusChips()
+    public void Header_UsesSevenWorkflowDestinations_WithoutDuplicateRuntimeStatusChips()
     {
         var document = XDocument.Parse(File.ReadAllText(FindRepoFile("MainWindow.xaml")));
         XNamespace p = "http://schemas.microsoft.com/winfx/2006/xaml/presentation";
@@ -20,7 +20,7 @@ public void Header_UsesSixWorkflowDestinations_WithoutDuplicateRuntimeStatusChip
         var navColumns = navGrid.Element(p + "Grid.ColumnDefinitions")?
             .Elements(p + "ColumnDefinition").Count() ?? 0;
 
-        Assert.Equal(6, navColumns);
+        Assert.Equal(7, navColumns);
         Assert.Contains(navGrid.Descendants(p + "Button"), button =>
             (string?)button.Attribute(x + "Name") == "NavAlarmButton" &&
             (string?)button.Attribute("Tag") == "3" &&
@@ -31,6 +31,9 @@ public void Header_UsesSixWorkflowDestinations_WithoutDuplicateRuntimeStatusChip
         Assert.Contains(navGrid.Descendants(p + "Button"), button =>
             (string?)button.Attribute(x + "Name") == "NavDiagnosticsButton" &&
             (string?)button.Attribute("Tag") == "5");
+        Assert.Contains(navGrid.Descendants(p + "Button"), button =>
+            (string?)button.Attribute(x + "Name") == "NavFatButton" &&
+            (string?)button.Attribute("Tag") == "6");
 
         var headerSource = header.ToString(SaveOptions.DisableFormatting);
         Assert.DoesNotContain("ConnectionInsightText", headerSource, StringComparison.Ordinal);
@@ -122,17 +125,17 @@ public void Annunciator_FlashAndAckWorkAreBoundedToVisibleIedOrIedRail()
     }
 
     [Fact]
-    public void NavigationAndDiagnosticsUseSixTabGeometry()
+    public void NavigationAndDiagnosticsUseSevenTabGeometry()
     {
         var navigation = File.ReadAllText(FindRepoFile("MainWindow.NavigationLayoutFix.cs"));
         var main = File.ReadAllText(FindRepoFile("MainWindow.xaml.cs"));
 
-        Assert.Contains("contentWidth / 6d", navigation, StringComparison.Ordinal);
-        Assert.Contains("Math.Clamp(tabs.SelectedIndex, 0, 5)", navigation, StringComparison.Ordinal);
+        Assert.Contains("contentWidth / 7d", navigation, StringComparison.Ordinal);
+        Assert.Contains("Math.Clamp(tabs.SelectedIndex, 0, 6)", navigation, StringComparison.Ordinal);
         Assert.Contains("NavAlarmButton", navigation, StringComparison.Ordinal);
         Assert.Contains("MainTabs.SelectedIndex == 4", main, StringComparison.Ordinal);
         Assert.Contains("MainTabs.SelectedIndex == 5", main, StringComparison.Ordinal);
-        Assert.Contains("Math.Clamp(index, 0, 5)", main, StringComparison.Ordinal);
+        Assert.Contains("Math.Clamp(index, 0, 6)", main, StringComparison.Ordinal);
     }
 
     [Fact]
diff --git a/tests/ARSAS.Tests/IntegratedFatWorkspaceRegressionTests.cs b/tests/ARSAS.Tests/IntegratedFatWorkspaceRegressionTests.cs
new file mode 100644
index 000000000..daf88162f
--- /dev/null
+++ b/tests/ARSAS.Tests/IntegratedFatWorkspaceRegressionTests.cs
@@ -0,0 +1,68 @@
+using System.Xml.Linq;
+
+namespace ARSAS.Tests;
+
+public sealed class IntegratedFatWorkspaceRegressionTests
+{
+    [Fact]
+    public void MainWindow_ExposesFatAsSeventhTabWithoutRemovingEngineeringTabs()
+    {
+        var document = XDocument.Load(FindRepoFile("MainWindow.xaml"));
+        XNamespace presentation = "http://schemas.microsoft.com/winfx/2006/xaml/presentation";
+        XNamespace x = "http://schemas.microsoft.com/winfx/2006/xaml";
+
+        var tabs = document.Descendants(presentation + "TabItem").ToArray();
+        Assert.Equal(7, tabs.Length);
+        Assert.Equal("FAT", (string?)tabs[^1].Attribute("Header"));
+        Assert.Contains(document.Descendants(), element =>
+            (string?)element.Attribute(x + "Name") == "NavFatButton" &&
+            (string?)element.Attribute("Tag") == "6");
+    }
+
+    [Fact]
+    public void SclOnlyLaunch_UsesIntegratedTabWhileLegacySourcesRemainFallback()
+    {
+        var source = File.ReadAllText(FindRepoFile("MainWindow.IoTesting.cs"));
+
+        Assert.Contains("launch.Project.Sources.All", source, StringComparison.Ordinal);
+        Assert.Contains("IoFatSourceKinds.Scl", source, StringComparison.Ordinal);
+        Assert.Contains("ShowIntegratedFatWorkspace(launch)", source, StringComparison.Ordinal);
+        Assert.Contains("new IoListTestingWindow", source, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void IntegratedFat_ReusesEngineeringIedsLiveValuesAndInPlacePreview()
+    {
+        var xaml = File.ReadAllText(FindRepoFile("IntegratedFatWorkspaceControl.xaml"));
+        var code = File.ReadAllText(FindRepoFile("IntegratedFatWorkspaceControl.xaml.cs"));
+
+        Assert.Contains("ItemsSource=\"{Binding EngineeringIeds}\"", xaml, StringComparison.Ordinal);
+        Assert.Contains("SelectedEngineeringIed", xaml, StringComparison.Ordinal);
+        Assert.Contains("Runtime.CurrentValue", xaml, StringComparison.Ordinal);
+        Assert.Contains("DisplaySignalName", xaml, StringComparison.Ordinal);
+        Assert.Contains("VALUE 1", xaml, StringComparison.Ordinal);
+        Assert.Contains("VALUE 2", xaml, StringComparison.Ordinal);
+        Assert.Contains("RESULT", xaml, StringComparison.Ordinal);
+        Assert.Contains("WorkspaceView.Visibility = Visibility.Collapsed", code, StringComparison.Ordinal);
+        Assert.Contains("PreviewView.Visibility = Visibility.Visible", code, StringComparison.Ordinal);
+        Assert.Contains("IoFatReportPreviewDocumentBuilder.Build", code, StringComparison.Ordinal);
+        Assert.DoesNotContain("new Window", code, StringComparison.Ordinal);
+
+        var navigation = File.ReadAllText(FindRepoFile("SasOperationalUiPolicy.cs"));
+        Assert.Contains("\"NavFatButton\"", navigation, StringComparison.Ordinal);
+    }
+
+    private static string FindRepoFile(string relativePath)
+    {
+        DirectoryInfo? directory = new(AppContext.BaseDirectory);
+        while (directory != null)
+        {
+            var candidate = Path.Combine(directory.FullName, relativePath);
+            if (File.Exists(candidate))
+                return candidate;
+            directory = directory.Parent;
+        }
+
+        throw new FileNotFoundException(relativePath);
+    }
+}
diff --git a/tests/ARSAS.Tests/IoFatReportPreviewServiceTests.cs b/tests/ARSAS.Tests/IoFatReportPreviewServiceTests.cs
index 3dc067805..0a043d677 100644
--- a/tests/ARSAS.Tests/IoFatReportPreviewServiceTests.cs
+++ b/tests/ARSAS.Tests/IoFatReportPreviewServiceTests.cs
@@ -30,6 +30,27 @@ public void CreateIedScopedProject_CreatesIsolatedSnapshotWithOnlySelectedIed()
         Assert.Equal(second.TestPoints[0].TestPointId, scoped.Ieds[0].TestPoints[0].TestPointId);
     }
 
+    [Fact]
+    public void ScopedPreview_PreservesLivePhaseReferenceForSemanticSignalName()
+    {
+        var ied = BuildIed(
+            "IED_A",
+            "192.168.1.10",
+            "A",
+            "IED_ALD/MMXU1.A",
+            "IED_ALD/MMXU1.A");
+        var point = ied.TestPoints[0];
+        point.ApplyLiveBinding(
+            IoTestLiveBindingState.LivePointReady,
+            "shared Engineering live point",
+            "DEVICE-A",
+            "IED_ALD/MMXU1.A.phsB.cVal.mag.f");
+
+        var scoped = IoFatReportPreviewService.CreateIedScopedProject(BuildProject(ied), ied);
+
+        Assert.Equal("A Phs B", scoped.Ieds[0].TestPoints[0].DisplaySignalName);
+    }
+
     [Fact]
     public void NativePerIedPdf_IsScopedToSelectedIed()
     {
@@ -195,7 +216,12 @@ public void IoFatPreparation_UsesCachedReconnect_AndAttachesToSharedMonitorWitho
         Ieds = ieds.ToList()
     };
 
-    private static IoTestIedPlan BuildIed(string name, string ip, string signalName) => new()
+    private static IoTestIedPlan BuildIed(
+        string name,
+        string ip,
+        string signalName,
+        string? sourceIecReference = null,
+        string? eventLogSearchReference = null) => new()
     {
         IedName = name,
         IpAddress = ip,
@@ -208,6 +234,8 @@ public void IoFatPreparation_UsesCachedReconnect_AndAttachesToSharedMonitorWitho
                 IpAddress = ip,
                 SignalName = signalName,
                 ObjectReference = $"{name}LD/GGIO1.Ind1.stVal",
+                SourceIecReference = sourceIecReference ?? string.Empty,
+                EventLogSearchReference = eventLogSearchReference ?? string.Empty,
                 FunctionalConstraint = "ST",
                 ExpectedOnText = "ON Operated",
                 ExpectedOffText = "OFF Normal"
diff --git a/tests/ARSAS.Tests/IoSignalDisplayNameTests.cs b/tests/ARSAS.Tests/IoSignalDisplayNameTests.cs
index 041f2308a..bf56062ae 100644
--- a/tests/ARSAS.Tests/IoSignalDisplayNameTests.cs
+++ b/tests/ARSAS.Tests/IoSignalDisplayNameTests.cs
@@ -5,9 +5,9 @@ namespace ARSAS.Tests;
 public sealed class IoSignalDisplayNameTests
 {
     [Theory]
-    [InlineData("IED1MEAS/MMXU1.A.phsA.cVal.mag.f", "A PhsA")]
-    [InlineData("IED1MEAS/MMXU1.A.phsB.cVal.mag.f", "A PhsB")]
-    [InlineData("IED1MEAS/MMXU1.A.phsC.cVal.mag.f", "A PhsC")]
+    [InlineData("IED1MEAS/MMXU1.A.phsA.cVal.mag.f", "A Phs A")]
+    [InlineData("IED1MEAS/MMXU1.A.phsB.cVal.mag.f", "A Phs B")]
+    [InlineData("IED1MEAS/MMXU1.A.phsC.cVal.mag.f", "A Phs C")]
     public void Format_AppendsPhaseContextWithoutAddingMeasurementOwner(string reference, string expected)
     {
         Assert.Equal(expected, IoSignalDisplayName.Format("A", reference));
diff --git a/tests/ARSAS.Tests/MainWindowTopBarLayoutRegressionTests.cs b/tests/ARSAS.Tests/MainWindowTopBarLayoutRegressionTests.cs
index 67a83f8a4..8aaa02217 100644
--- a/tests/ARSAS.Tests/MainWindowTopBarLayoutRegressionTests.cs
+++ b/tests/ARSAS.Tests/MainWindowTopBarLayoutRegressionTests.cs
@@ -3,7 +3,7 @@ namespace ARSAS.Tests;
 public sealed class MainWindowTopBarLayoutRegressionTests
 {
     [Fact]
-    public void NavigationLayout_UsesResponsiveWidthsAndConsistentSixDestinationLabels()
+    public void NavigationLayout_UsesResponsiveWidthsAndConsistentSevenDestinationLabels()
     {
         var source = File.ReadAllText(FindRepoFile("MainWindow.NavigationLayoutFix.cs"));
 
@@ -14,16 +14,17 @@ public void NavigationLayout_UsesResponsiveWidthsAndConsistentSixDestinationLabe
         Assert.Contains("\"Alarm\"", source, StringComparison.Ordinal);
         Assert.DoesNotContain("\"Alarm Annunciator\"", source, StringComparison.Ordinal);
         Assert.Contains("\"GOOSE Subscriber\"", source, StringComparison.Ordinal);
+        Assert.Contains("\"FAT\"", source, StringComparison.Ordinal);
         Assert.Contains("var labels = wide ? FullLabels : CompactLabels", source, StringComparison.Ordinal);
     }
 
     [Fact]
-    public void SelectionPill_IsDerivedFromActualSixCellNavWidth_NotFixed150Pixels()
+    public void SelectionPill_IsDerivedFromActualSevenCellNavWidth_NotFixed150Pixels()
     {
         var source = File.ReadAllText(FindRepoFile("MainWindow.NavigationLayoutFix.cs"));
 
-        Assert.Contains("var cellWidth = contentWidth / 6d", source, StringComparison.Ordinal);
-        Assert.Contains("Math.Clamp(tabs.SelectedIndex, 0, 5) * cellWidth", source, StringComparison.Ordinal);
+        Assert.Contains("var cellWidth = contentWidth / 7d", source, StringComparison.Ordinal);
+        Assert.Contains("Math.Clamp(tabs.SelectedIndex, 0, 6) * cellWidth", source, StringComparison.Ordinal);
         Assert.Contains("pill.Width = Math.Max(1d, cellWidth - 2d)", source, StringComparison.Ordinal);
         Assert.Contains("FindName(\"WorkflowPillTranslate\") as TranslateTransform", source, StringComparison.Ordinal);
         Assert.Contains("pill.RenderTransform is TransformGroup", source, StringComparison.Ordinal);
diff --git a/tests/ARSAS.Tests/P0LatestFieldRegressionTests.cs b/tests/ARSAS.Tests/P0LatestFieldRegressionTests.cs
index 34f93fb49..8c5a76a75 100644
--- a/tests/ARSAS.Tests/P0LatestFieldRegressionTests.cs
+++ b/tests/ARSAS.Tests/P0LatestFieldRegressionTests.cs
@@ -6,11 +6,12 @@ namespace ARSAS.Tests;
 public sealed class P0LatestFieldRegressionTests
 {
     [Theory]
-    [InlineData("A", "IEDLD/MMXU1.A.phsA.cVal.mag.f", "A PhsA")]
-    [InlineData("A", "IEDLD/MMXU1.A.phsB.cVal.mag.f", "A PhsB")]
-    [InlineData("A", "IEDLD/MMXU1.A.phsC.cVal.mag.f", "A PhsC")]
-    [InlineData("ThdA", "IEDLD/MMXU1.ThdA.phsA.instMag.f", "ThdA PhsA")]
-    [InlineData("ThdPPV", "IEDLD/MMXU1.ThdPPV.phsAB.instMag.f", "ThdPPV PhsAB")]
+    [InlineData("A", "IEDLD/MMXU1.A.phsA.cVal.mag.f", "A Phs A")]
+    [InlineData("A", "IEDLD/MMXU1.A.phsB.cVal.mag.f", "A Phs B")]
+    [InlineData("A", "IEDLD/MMXU1.A.phsC.cVal.mag.f", "A Phs C")]
+    [InlineData("ThdA", "IEDLD/MMXU1.ThdA.phsA.instMag.f", "Thd Phs A")]
+    [InlineData("PPV", "IEDLD/MMXU1.PPV.phsAB.instMag.f", "PPV Phs AB")]
+    [InlineData("ThdPPV", "IEDLD/MMXU1.ThdPPV.phsAB.instMag.f", "ThdPPV Phs AB")]
     public void FatSignalDisplayName_PreservesDoFamilyAndAddsCompactPhaseContext(
         string signalName,
         string reference,
@@ -21,6 +22,17 @@ public void FatSignalDisplayName_PreservesDoFamilyAndAddsCompactPhaseContext(
         Assert.Equal(reference, reference); // presentation must never rewrite technical identity
     }
 
+    [Fact]
+    public void FatSignalDisplayName_UsesLiveReferenceWhenReportIdentityLostPhaseContext()
+    {
+        var actual = IoSignalDisplayName.FormatFromCandidates(
+            "A",
+            "IEDLD/MMXU1.A.phsB.cVal.mag.f",
+            "IEDLD/MMXU1.A");
+
+        Assert.Equal("A Phs B", actual);
+    }
+
     [Fact]
     public void RemovedFatSignals_AreFilteredFromActiveGridWithoutSilentlyUntickingTest()
     {