diff --git a/DRAMSys/traceAnalyzer/CMakeLists.txt b/DRAMSys/traceAnalyzer/CMakeLists.txt
index ae70b48c..96594a93 100644
--- a/DRAMSys/traceAnalyzer/CMakeLists.txt
+++ b/DRAMSys/traceAnalyzer/CMakeLists.txt
@@ -75,7 +75,6 @@ add_executable(TraceAnalyzer
     presentation/tracescroller.cpp
     traceanalyzer.cpp
     presentation/transactiontreewidget.cpp
-    presentation/commenttreewidget.cpp
     presentation/util/clkgrid.cpp
     queryeditor.cpp
     presentation/selectedtransactiontreewidget.cpp
@@ -97,6 +96,7 @@ add_executable(TraceAnalyzer
     presentation/util/customlabelscaledraw.cpp
     presentation/traceselector.cpp
     businessObjects/configmodels.cpp
+    businessObjects/commentmodel.cpp
 
     selectmetrics.ui
     preferences.ui
diff --git a/DRAMSys/traceAnalyzer/businessObjects/comment.h b/DRAMSys/traceAnalyzer/businessObjects/comment.h
deleted file mode 100644
index c52753f8..00000000
--- a/DRAMSys/traceAnalyzer/businessObjects/comment.h
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
- * Copyright (c) 2015, Technische Universität Kaiserslautern
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- * 1. Redistributions of source code must retain the above copyright notice,
- *    this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * 3. Neither the name of the copyright holder nor the names of its
- *    contributors may be used to endorse or promote products derived from
- *    this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
- * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER
- * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
- * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
- * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * Authors:
- *    Janik Schlemminger
- *    Robert Gernhardt
- *    Matthias Jung
- *    Derek Christ
- */
-
-#ifndef COMMENT_H
-#define COMMENT_H
-#include <QString>
-#include "timespan.h"
-
-class Comment
-{
-    traceTime time;
-    QString text;
-public:
-    Comment(traceTime time, QString text): time(time), text(text) {}
-    traceTime Time() const
-    {
-        return time;
-    }
-    const QString &Text() const
-    {
-        return text;
-    }
-    void changeText(QString newText)
-    {
-        text = newText;
-    }
-};
-
-#endif // COMMENT_H
diff --git a/DRAMSys/traceAnalyzer/businessObjects/commentmodel.cpp b/DRAMSys/traceAnalyzer/businessObjects/commentmodel.cpp
new file mode 100644
index 00000000..c6cdad28
--- /dev/null
+++ b/DRAMSys/traceAnalyzer/businessObjects/commentmodel.cpp
@@ -0,0 +1,305 @@
+/*
+ * Copyright (c) 2021, Technische Universität Kaiserslautern
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors:
+ *    Derek Christ
+ */
+
+#include "commentmodel.h"
+
+#include <QMenu>
+#include <QItemSelectionModel>
+#include <QKeyEvent>
+
+CommentModel::CommentModel(QObject *parent) : QAbstractTableModel(parent),
+    gotoAction(new QAction("Goto comment", this)),
+    editAction(new QAction("Edit comment", this)),
+    deleteAction(new QAction("Delete comment", this)),
+    selectAllAction(new QAction("Select all comments", this)),
+    deselectAllAction(new QAction("Deselect all comments", this)),
+    internalSelectionModel(new QItemSelectionModel(this, this))
+{
+    setUpActions();
+}
+
+void CommentModel::setUpActions()
+{
+    QObject::connect(gotoAction, &QAction::triggered, this, [=](){
+        const QModelIndexList indexes = internalSelectionModel->selectedRows();
+        for (const QModelIndex &currentIndex : indexes)
+        {
+            emit gotoCommentTriggered(currentIndex);
+        }
+    });
+
+    QObject::connect(editAction, &QAction::triggered, this, [=](){
+        const QModelIndexList indexes = internalSelectionModel->selectedRows();
+        for (const QModelIndex &currentIndex : indexes)
+            emit editTriggered(index(currentIndex.row(), static_cast<int>(Column::Comment)));
+    });
+
+    QObject::connect(deleteAction, &QAction::triggered, this, [=](){
+        const QModelIndexList indexes = internalSelectionModel->selectedRows();
+        for (const QModelIndex &currentIndex : indexes)
+            removeComment(currentIndex);
+    });
+
+    QObject::connect(selectAllAction, &QAction::triggered, this, [=](){
+        QModelIndex topLeft = index(0, 0);
+        QModelIndex bottomRight = index(rowCount() - 1, columnCount() - 1);
+        internalSelectionModel->select(QItemSelection(topLeft, bottomRight),
+                                       QItemSelectionModel::Select | QItemSelectionModel::Rows);
+    });
+
+    QObject::connect(deselectAllAction, &QAction::triggered,
+                     internalSelectionModel, &QItemSelectionModel::clearSelection);
+}
+
+int CommentModel::rowCount(const QModelIndex &parent) const
+{
+    Q_UNUSED(parent)
+
+    return comments.size();
+}
+
+int CommentModel::columnCount(const QModelIndex &parent) const
+{
+    Q_UNUSED(parent)
+
+    return static_cast<int>(Column::COLUMNCOUNT);
+}
+
+QVariant CommentModel::data(const QModelIndex &index, int role) const
+{
+    if (!index.isValid())
+        return QVariant();
+
+    // Qt::UserRole is used to get the raw time without pretty formatting.
+    if (role != Qt::DisplayRole && role != Qt::EditRole && role != Qt::UserRole)
+        return QVariant();
+
+    const Comment &comment = comments.at(index.row());
+
+    if (role == Qt::UserRole && static_cast<Column>(index.column()) == Column::Time)
+        return QVariant(comment.time);
+
+    switch (static_cast<Column>(index.column())) {
+    case Column::Time:
+        return QVariant(prettyFormatTime(comment.time));
+    case Column::Comment:
+        return QVariant(comment.text);
+    default:
+        break;
+    }
+
+    return QVariant();
+}
+
+bool CommentModel::setData(const QModelIndex &index, const QVariant &value, int role)
+{
+    if (!index.isValid())
+        return false;
+
+    if (role != Qt::EditRole)
+        return false;
+
+    if (static_cast<Column>(index.column()) != Column::Comment)
+        return false;
+
+    QString newText = value.toString();
+
+    Comment &comment = comments.at(index.row());
+    comment.text = newText;
+
+    emit dataChanged(index, index);
+    return true;
+}
+
+QVariant CommentModel::headerData(int section, Qt::Orientation orientation, int role) const
+{
+    if (role != Qt::DisplayRole)
+        return QVariant();
+
+    if (orientation == Qt::Horizontal)
+    {
+        switch (static_cast<Column>(section)) {
+        case Column::Time:
+            return "Time";
+        case Column::Comment:
+            return "Comment";
+        default:
+            break;
+        }
+    }
+
+    return QVariant();
+}
+
+Qt::ItemFlags CommentModel::flags(const QModelIndex &index) const
+{
+    Qt::ItemFlags flags = QAbstractItemModel::flags(index);
+
+    if (index.isValid() && index.column() == static_cast<int>(Column::Comment))
+        flags |= Qt::ItemIsEditable;
+
+    return flags;
+}
+
+void CommentModel::openContextMenu()
+{
+    if (!internalSelectionModel->hasSelection())
+        return;
+
+    QMenu *menu = new QMenu();
+    menu->addActions({gotoAction, editAction, deleteAction});
+    menu->addSeparator();
+    menu->addActions({selectAllAction, deselectAllAction});
+
+    QObject::connect(menu, &QMenu::aboutToHide, [=]() {
+        menu->deleteLater();
+    });
+
+    menu->popup(QCursor::pos());
+}
+
+QItemSelectionModel *CommentModel::selectionModel() const
+{
+    return internalSelectionModel;
+}
+
+void CommentModel::addComment(traceTime time)
+{
+    auto commentIt = std::find_if(comments.rbegin(), comments.rend(), [time](const Comment &comment){
+        return comment.time <= time;
+    });
+
+    int insertIndex = std::distance(comments.begin(), commentIt.base());
+
+    beginInsertRows(QModelIndex(), insertIndex, insertIndex);
+    comments.insert(comments.begin() + insertIndex, {time, "Enter comment text..."});
+    endInsertRows();
+
+    internalSelectionModel->setCurrentIndex(index(insertIndex, 0),
+                                            QItemSelectionModel::ClearAndSelect | QItemSelectionModel::Rows);
+
+    emit editTriggered(index(insertIndex, 1));
+}
+
+void CommentModel::addComment(traceTime time, QString text)
+{
+    auto commentIt = std::find_if(comments.rbegin(), comments.rend(), [time](const Comment &comment){
+        return comment.time <= time;
+    });
+
+    int insertIndex = std::distance(comments.begin(), commentIt.base());
+
+    beginInsertRows(QModelIndex(), insertIndex, insertIndex);
+    comments.insert(comments.begin() + insertIndex, {time, text});
+    endInsertRows();
+}
+
+void CommentModel::removeComment(traceTime time)
+{
+    auto commentIt = std::find_if(comments.begin(), comments.end(), [time](const Comment &comment){
+        return comment.time == time;
+    });
+
+    if (commentIt == comments.end())
+        return;
+
+    int removeIndex = std::distance(comments.begin(), commentIt);
+
+    beginRemoveRows(QModelIndex(), removeIndex, removeIndex);
+    comments.erase(commentIt);
+    endRemoveRows();
+}
+
+void CommentModel::removeComment(const QModelIndex &index)
+{
+    beginRemoveRows(QModelIndex(), index.row(), index.row());
+    comments.erase(comments.begin() + index.row());
+    endRemoveRows();
+}
+
+const std::vector<CommentModel::Comment> &CommentModel::getComments() const
+{
+    return comments;
+}
+
+traceTime CommentModel::getTimeFromIndex(const QModelIndex &index) const
+{
+    Q_ASSERT(comments.size() > index.row());
+
+    return comments[index.row()].time;
+}
+
+QModelIndex CommentModel::hoveredComment(Timespan timespan) const
+{
+    auto commentIt = std::find_if(comments.begin(), comments.end(), [timespan](const Comment &comment){
+        return timespan.Begin() < comment.time && comment.time < timespan.End();
+    });
+
+    if (commentIt == comments.end())
+        return QModelIndex();
+
+    int commentIndex = std::distance(comments.begin(), commentIt);
+
+    return index(commentIndex, 0);
+}
+
+bool CommentModel::eventFilter(QObject *object, QEvent *event)
+{
+    Q_UNUSED(object)
+
+    if (event->type() == QEvent::KeyPress)
+    {
+        QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
+        if (keyEvent->key() == Qt::Key_Delete)
+        {
+            const QModelIndexList indexes = internalSelectionModel->selectedRows();
+            for (const QModelIndex &currentIndex : indexes)
+            {
+                removeComment(currentIndex);
+            }
+        }
+    }
+
+    return false;
+}
+
+void CommentModel::rowDoubleClicked(const QModelIndex &index)
+{
+    if (!index.isValid())
+        return;
+
+    if (static_cast<Column>(index.column()) == Column::Time)
+        Q_EMIT gotoCommentTriggered(index);
+}
diff --git a/DRAMSys/traceAnalyzer/businessObjects/commentmodel.h b/DRAMSys/traceAnalyzer/businessObjects/commentmodel.h
new file mode 100644
index 00000000..a9e165a6
--- /dev/null
+++ b/DRAMSys/traceAnalyzer/businessObjects/commentmodel.h
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2021, Technische Universität Kaiserslautern
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors:
+ *    Derek Christ
+ */
+
+#ifndef COMMENTMODEL_H
+#define COMMENTMODEL_H
+
+#include "tracetime.h"
+#include "timespan.h"
+
+#include <QAbstractTableModel>
+#include <utility>
+
+class QAction;
+class QItemSelectionModel;
+
+class CommentModel : public QAbstractTableModel
+{
+    Q_OBJECT
+
+public:
+    explicit CommentModel(QObject *parent = nullptr);
+
+    struct Comment {
+        traceTime time;
+        QString text;
+    };
+
+    int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+    int columnCount(const QModelIndex &parent = QModelIndex()) const override;
+
+    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
+    QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const override;
+
+    Qt::ItemFlags flags(const QModelIndex &index) const override;
+
+    enum class Column {
+        Time = 0,
+        Comment,
+        COLUMNCOUNT
+    };
+
+    void openContextMenu();
+
+    QItemSelectionModel *selectionModel() const;
+
+    void addComment(traceTime time);
+    void addComment(traceTime time, QString text);
+
+    void removeComment(traceTime time);
+    void removeComment(const QModelIndex &index);
+
+    const std::vector<Comment> &getComments() const;
+
+    traceTime getTimeFromIndex(const QModelIndex &index) const;
+
+    QModelIndex hoveredComment(Timespan timespan) const;
+
+public Q_SLOTS:
+    void rowDoubleClicked(const QModelIndex &index);
+
+protected:
+    bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole) override;
+
+    /**
+     * The eventFilter is used to delete comments using the delete key.
+     */
+    bool eventFilter(QObject *object, QEvent *event) override;
+
+Q_SIGNALS:
+    void editTriggered(const QModelIndex &index);
+    void gotoCommentTriggered(const QModelIndex &index);
+
+private:
+    void setUpActions();
+
+    std::vector<Comment> comments;
+
+    QAction *gotoAction;
+    QAction *editAction;
+    QAction *deleteAction;
+    QAction *selectAllAction;
+    QAction *deselectAllAction;
+
+    QItemSelectionModel *internalSelectionModel;
+};
+
+#endif // COMMENTMODEL_H
diff --git a/DRAMSys/traceAnalyzer/data/tracedb.cpp b/DRAMSys/traceAnalyzer/data/tracedb.cpp
index a7061a70..ff37a88f 100644
--- a/DRAMSys/traceAnalyzer/data/tracedb.cpp
+++ b/DRAMSys/traceAnalyzer/data/tracedb.cpp
@@ -44,7 +44,6 @@
 #include <QFileInfo>
 #include <QDebug>
 #include "data/tracedb.h"
-#include "businessObjects/comment.h"
 #include "businessObjects/phases/phasefactory.h"
 
 
@@ -87,7 +86,7 @@ void TraceDB::prepareQueries()
     selectDebugMessagesByTimespanWithLimit.prepare("SELECT time, Message FROM DebugMessages WHERE :begin <= time AND time <= :end LIMIT :limit");
 }
 
-void TraceDB::updateComments(vector<Comment> comments)
+void TraceDB::updateComments(const std::vector<CommentModel::Comment> &comments)
 {
 
     QSqlQuery query(database);
@@ -95,9 +94,10 @@ void TraceDB::updateComments(vector<Comment> comments)
     executeQuery(query);
     query.prepare("insert into Comments values(:time,:text)");
 
-    for (const Comment &comment : comments) {
-        query.bindValue(":time", comment.Time());
-        query.bindValue(":text", comment.Text());
+    for (const auto &comment : comments)
+    {
+        query.bindValue(":time", comment.time);
+        query.bindValue(":text", comment.text);
         executeQuery(query);
     }
 }
@@ -341,7 +341,7 @@ unsigned int TraceDB::getNumberOfPhases()
     return query.value(0).toInt();
 }
 
-vector<Comment> TraceDB::getComments()
+vector<CommentModel::Comment> TraceDB::getComments()
 {
     QSqlQuery query(database);
     query.prepare("SELECT Time,Text From Comments");
@@ -350,7 +350,7 @@ vector<Comment> TraceDB::getComments()
 }
 
 
-vector<Comment> TraceDB::getDebugMessagesInTimespan(const Timespan &span)
+vector<CommentModel::Comment> TraceDB::getDebugMessagesInTimespan(const Timespan &span)
 {
     selectDebugMessagesByTimespan.bindValue(":begin", span.Begin());
     selectDebugMessagesByTimespan.bindValue(":end", span.End());
@@ -359,7 +359,7 @@ vector<Comment> TraceDB::getDebugMessagesInTimespan(const Timespan &span)
     return parseCommentsFromQuery(selectDebugMessagesByTimespan);
 }
 
-vector<Comment> TraceDB::getDebugMessagesInTimespan(const Timespan &span,
+vector<CommentModel::Comment> TraceDB::getDebugMessagesInTimespan(const Timespan &span,
                                                     unsigned int limit = 50)
 {
     selectDebugMessagesByTimespanWithLimit.bindValue(":begin", span.Begin());
@@ -432,12 +432,12 @@ vector<shared_ptr<Transaction>> TraceDB::parseTransactionsFromQuery(
     return result;
 }
 
-vector<Comment> TraceDB::parseCommentsFromQuery(QSqlQuery &query)
+vector<CommentModel::Comment> TraceDB::parseCommentsFromQuery(QSqlQuery &query)
 {
-    vector<Comment> result;
+    vector<CommentModel::Comment> result;
     while (query.next()) {
-        result.push_back(Comment(query.value(0).toLongLong(),
-                                 query.value(1).toString()));
+        result.push_back(CommentModel::Comment{query.value(0).toLongLong(),
+                                               query.value(1).toString()});
     }
     return result;
 }
diff --git a/DRAMSys/traceAnalyzer/data/tracedb.h b/DRAMSys/traceAnalyzer/data/tracedb.h
index 5df215b1..511be6b0 100644
--- a/DRAMSys/traceAnalyzer/data/tracedb.h
+++ b/DRAMSys/traceAnalyzer/data/tracedb.h
@@ -50,7 +50,7 @@
 #include "businessObjects/generalinfo.h"
 #include "businessObjects/commandlengths.h"
 #include "businessObjects/phases/phasefactory.h"
-#include "businessObjects/comment.h"
+#include "businessObjects/commentmodel.h"
 #include "QueryTexts.h"
 
 /*  TraceDB handles the connection to a SQLLite database containing trace data.
@@ -68,7 +68,7 @@ public:
         return pathToDB;
     }
 
-    void updateComments(std::vector<Comment> comments);
+    void updateComments(const std::vector<CommentModel::Comment> &comments);
     void updateFileDescription(const QString &description);
     void refreshData();
 
@@ -98,9 +98,9 @@ public:
     std::shared_ptr<Transaction> getTransactionByID(ID id);
     ID getTransactionIDFromPhaseID(ID phaseID);
 
-    std::vector<Comment> getComments();
-    std::vector<Comment> getDebugMessagesInTimespan(const Timespan &span);
-    std::vector<Comment> getDebugMessagesInTimespan(const Timespan &span,
+    std::vector<CommentModel::Comment> getComments();
+    std::vector<CommentModel::Comment> getDebugMessagesInTimespan(const Timespan &span);
+    std::vector<CommentModel::Comment> getDebugMessagesInTimespan(const Timespan &span,
                                                     unsigned int limit);
 
     QSqlDatabase getDatabase() const;
@@ -125,7 +125,7 @@ private:
     std::shared_ptr<Transaction> parseTransactionFromQuery(QSqlQuery &query);
     std::vector<std::shared_ptr<Transaction>> parseTransactionsFromQuery(
                                                QSqlQuery &query);
-    std::vector<Comment> parseCommentsFromQuery(QSqlQuery &query);
+    std::vector<CommentModel::Comment> parseCommentsFromQuery(QSqlQuery &query);
 
     void executeScriptFile(QString fileName);
     void dropAndCreateTables();
diff --git a/DRAMSys/traceAnalyzer/presentation/commenttreewidget.cpp b/DRAMSys/traceAnalyzer/presentation/commenttreewidget.cpp
deleted file mode 100644
index 519e04e4..00000000
--- a/DRAMSys/traceAnalyzer/presentation/commenttreewidget.cpp
+++ /dev/null
@@ -1,142 +0,0 @@
-/*
- * Copyright (c) 2015, Technische Universität Kaiserslautern
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- * 1. Redistributions of source code must retain the above copyright notice,
- *    this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * 3. Neither the name of the copyright holder nor the names of its
- *    contributors may be used to endorse or promote products derived from
- *    this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
- * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER
- * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
- * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
- * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * Authors:
- *    Janik Schlemminger
- *    Robert Gernhardt
- *    Matthias Jung
- *    Derek Christ
- */
-
-#include "commenttreewidget.h"
-#include <QTreeWidgetItem>
-#include <iostream>
-#include <QMenu>
-#include <QKeyEvent>
-#include <QInputDialog>
-#include <QLineEdit>
-
-CommentTreeWidget::CommentTreeWidget(QWidget *parent) : QTreeWidget(parent),
-    deleteComment(new QAction("Delete comment", this)),
-    changeCommentText(new QAction("Change comment text", this))
-{
-    connect(deleteComment, &QAction::triggered, this, [this](){
-        for (QTreeWidgetItem *item : selectedItems())
-        {
-            CommentTreeItem *commentItem = static_cast<CommentTreeItem *>(item);
-            navigator->removeCommentAtTime(commentItem->Time());
-        }
-    });
-
-    connect(changeCommentText, &QAction::triggered, this, [this](){
-        for (QTreeWidgetItem *item : selectedItems())
-        {
-            CommentTreeItem *commentItem = static_cast<CommentTreeItem *>(item);
-
-            bool ok;
-            QString newText = QInputDialog::getText(this, QString("Change comment text"),
-                                                    QString("Change comment text"), QLineEdit::Normal,
-                                                    QString(), &ok);
-
-            if (ok)
-            {
-                deleteComment->trigger();
-                navigator->insertComment({commentItem->Time(), newText});
-            }
-
-            commentsChanged();
-        }
-    });
-}
-
-void CommentTreeWidget::init(TraceNavigator *navigator)
-{
-    Q_ASSERT(isInitialized == false);
-    isInitialized = true;
-    this->navigator = navigator;
-    setColumnCount(2);
-    setHeaderLabels(QStringList({"Time", "Comment"}));
-    QObject::connect(navigator, SIGNAL(commentsChanged()), this,
-                     SLOT(commentsChanged()));
-    QObject::connect(this, SIGNAL(itemDoubleClicked(QTreeWidgetItem *, int)), this,
-                     SLOT(itemDoubleClicked(QTreeWidgetItem *, int)));
-    QObject::connect(this, SIGNAL(customContextMenuRequested(QPoint)), this,
-                     SLOT(ContextMenuRequested(QPoint)));
-    setContextMenuPolicy(Qt::CustomContextMenu);
-    printComments();
-}
-
-void CommentTreeWidget::commentsChanged()
-{
-    clear();
-    printComments();
-}
-
-void CommentTreeWidget::printComments()
-{
-    for (const auto &pair : navigator->getComments()) {
-        const Comment &comment = pair.second;
-        QTreeWidgetItem *item = new CommentTreeItem(this, comment);
-        addTopLevelItem(item);
-    }
-    resizeColumnToContents(0);
-}
-
-void CommentTreeWidget::itemDoubleClicked(QTreeWidgetItem *item, int /*column*/)
-{
-    CommentTreeItem *commentItem = static_cast<CommentTreeItem *>(item);
-    navigator->navigateToTime(commentItem->Time());
-}
-
-void CommentTreeWidget::ContextMenuRequested(QPoint point)
-{
-    QMenu contextMenu(this);
-    contextMenu.addActions({deleteComment, changeCommentText});
-    contextMenu.exec(mapToGlobal(point));
-}
-
-
-CommentTreeWidget::CommentTreeItem::CommentTreeItem(QTreeWidget *parent,
-                                                    const Comment &comment): QTreeWidgetItem(parent), comment(comment)
-{
-    this->setText(0, prettyFormatTime(comment.Time()));
-    this->setText(1, comment.Text());
-}
-
-void CommentTreeWidget::keyPressEvent(QKeyEvent *event)
-{
-    if (event->key() == Qt::Key_Delete)
-        deleteComment->trigger();
-    else if (event->key() == Qt::Key_F2)
-        changeCommentText->trigger();
-
-    QTreeWidget::keyPressEvent(event);
-}
diff --git a/DRAMSys/traceAnalyzer/presentation/commenttreewidget.h b/DRAMSys/traceAnalyzer/presentation/commenttreewidget.h
deleted file mode 100644
index 7429f75e..00000000
--- a/DRAMSys/traceAnalyzer/presentation/commenttreewidget.h
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
- * Copyright (c) 2015, Technische Universität Kaiserslautern
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- * 1. Redistributions of source code must retain the above copyright notice,
- *    this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * 3. Neither the name of the copyright holder nor the names of its
- *    contributors may be used to endorse or promote products derived from
- *    this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
- * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER
- * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
- * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
- * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * Authors:
- *    Janik Schlemminger
- *    Robert Gernhardt
- *    Matthias Jung
- *    Derek Christ
- */
-
-#ifndef COMMENTTREEWIDGET_H
-#define COMMENTTREEWIDGET_H
-#include <QTreeWidget>
-#include <QTreeWidgetItem>
-#include <QAction>
-#include "businessObjects/comment.h"
-#include "tracenavigator.h"
-
-class CommentTreeWidget : public QTreeWidget
-{
-    Q_OBJECT
-
-public:
-    CommentTreeWidget(QWidget *parent = nullptr);
-    void init(TraceNavigator *navigator);
-
-protected:
-    void keyPressEvent(QKeyEvent *event) override;
-
-private Q_SLOTS:
-    void commentsChanged();
-    void ContextMenuRequested(QPoint point);
-    void itemDoubleClicked(QTreeWidgetItem *item, int column);
-
-private:
-    bool isInitialized = false;
-    TraceNavigator *navigator;
-    void printComments();
-    QAction *deleteComment;
-    QAction *changeCommentText;
-
-    class CommentTreeItem : public QTreeWidgetItem
-    {
-    private:
-        Comment comment;
-    public:
-        CommentTreeItem(QTreeWidget *parent, const Comment &comment);
-        QString Text()
-        {
-            return comment.Text();
-        }
-        traceTime Time()
-        {
-            return comment.Time();
-        }
-        void changeText(QString newText)
-        {
-            comment.changeText(newText);
-        }
-    };
-};
-
-#endif // COMMENTTREEWIDGET_H
diff --git a/DRAMSys/traceAnalyzer/presentation/debugmessagetreewidget.cpp b/DRAMSys/traceAnalyzer/presentation/debugmessagetreewidget.cpp
index df4bdee1..13f1cc7c 100644
--- a/DRAMSys/traceAnalyzer/presentation/debugmessagetreewidget.cpp
+++ b/DRAMSys/traceAnalyzer/presentation/debugmessagetreewidget.cpp
@@ -84,19 +84,19 @@ void DebugMessageTreeWidget::currentTraceTimeChanged()
                               traceplot->GetCurrentTimespan()));
 }
 
-void DebugMessageTreeWidget::showDebugMessages(const vector<Comment> &comments)
+void DebugMessageTreeWidget::showDebugMessages(const vector<CommentModel::Comment> &comments)
 {
     clear();
     if (comments.empty())
         return;
 
     traceTime currentTime = -1;
-    for (Comment comment : comments) {
-        if (currentTime != comment.Time()) {
-            addTopLevelItem(new QTreeWidgetItem({prettyFormatTime(comment.Time()), formatDebugMessage(comment.Text())}));
-            currentTime = comment.Time();
+    for (const auto &comment : comments) {
+        if (currentTime != comment.time) {
+            addTopLevelItem(new QTreeWidgetItem({prettyFormatTime(comment.time), formatDebugMessage(comment.text)}));
+            currentTime = comment.time;
         } else {
-            addTopLevelItem(new QTreeWidgetItem({"", formatDebugMessage(comment.Text())}));
+            addTopLevelItem(new QTreeWidgetItem({"", formatDebugMessage(comment.text)}));
         }
     }
 
diff --git a/DRAMSys/traceAnalyzer/presentation/debugmessagetreewidget.h b/DRAMSys/traceAnalyzer/presentation/debugmessagetreewidget.h
index 906188c6..225a5bf0 100644
--- a/DRAMSys/traceAnalyzer/presentation/debugmessagetreewidget.h
+++ b/DRAMSys/traceAnalyzer/presentation/debugmessagetreewidget.h
@@ -42,7 +42,7 @@
 #include <QString>
 #include <QRegularExpression>
 #include <QMouseEvent>
-#include "businessObjects/comment.h"
+#include "businessObjects/commentmodel.h"
 #include "tracenavigator.h"
 #include "traceplot.h"
 
@@ -56,7 +56,7 @@ public:
         hexAdressMatcher(QString("0x[0-9,a-f]+")) {}
     void init(TraceNavigator *navigator, TracePlot *traceplot);
 
-    void showDebugMessages(const std::vector<Comment> &comments);
+    void showDebugMessages(const std::vector<CommentModel::Comment> &comments);
     void arrangeUiSettings();
 
 public Q_SLOTS:
diff --git a/DRAMSys/traceAnalyzer/presentation/tracenavigator.cpp b/DRAMSys/traceAnalyzer/presentation/tracenavigator.cpp
index 13b0526c..f5ab5a0b 100644
--- a/DRAMSys/traceAnalyzer/presentation/tracenavigator.cpp
+++ b/DRAMSys/traceAnalyzer/presentation/tracenavigator.cpp
@@ -39,14 +39,24 @@
 #include "tracenavigator.h"
 #include "util/traceplotlinecache.h"
 #include "vector"
+#include "businessObjects/commentmodel.h"
+#include <QInputDialog>
+#include <QLineEdit>
 
 using namespace std;
 
-TraceNavigator::TraceNavigator(QString path, QObject *parent)
-    : QObject(parent), traceFile(path, true), changesToCommitExist(false)
+TraceNavigator::TraceNavigator(QString path, CommentModel *commentModel, QObject *parent)
+    : QObject(parent), traceFile(path, true), commentModel(commentModel), changesToCommitExist(false)
 {
     getCommentsFromDB();
 
+    QObject::connect(commentModel, &CommentModel::gotoCommentTriggered, this, [=](const QModelIndex &index){
+        navigateToTime(commentModel->getTimeFromIndex(index));
+    });
+
+    QObject::connect(commentModel, &CommentModel::dataChanged, this, &TraceNavigator::traceFileModified);
+    QObject::connect(commentModel, &CommentModel::rowsRemoved, this, &TraceNavigator::traceFileModified);
+
     tracePlotLineCache =
         std::make_shared<TracePlotLineCache>(getTracePlotLines(), GeneralTraceInfo().numberOfRanks,
                                              GeneralTraceInfo().groupsPerRank, GeneralTraceInfo().banksPerGroup);
@@ -79,49 +89,20 @@ void TraceNavigator::navigateToTransaction(ID id)
     navigateToTime(traceFile.getTransactionByID(id)->span.Begin());
 }
 
-
-/* Comment and debug messages
- *
- */
-void TraceNavigator::insertComment(const Comment &comment)
-{
-    comments.emplace(comment.Time(), comment);
-    changesToCommitExist = true;
-    Q_EMIT commentsChanged();
-}
-
-void TraceNavigator::removeCommentAtTime(traceTime time)
-{
-    auto found = comments.find(time);
-    if (found != comments.end()) {
-        comments.erase(found);
-        changesToCommitExist = true;
-        Q_EMIT commentsChanged();
-    }
-}
-
-
-
 /* DB
  *
  */
 
 void TraceNavigator::commitChangesToDB()
 {
-    vector<Comment> commentsToInsert;
-    for (const auto &pair : comments) {
-        commentsToInsert.push_back(pair.second);
-    }
-
-    traceFile.updateComments(commentsToInsert);
+    traceFile.updateComments(commentModel->getComments());
     changesToCommitExist = false;
 }
 
 void TraceNavigator::getCommentsFromDB()
 {
-    for (const Comment &comment : traceFile.getComments()) {
-        comments.emplace(comment.Time(), comment);
-    }
+    for (const auto &comment : traceFile.getComments())
+        commentModel->addComment(comment.time, comment.text);
 }
 
 void TraceNavigator::refreshData()
@@ -334,3 +315,18 @@ std::shared_ptr<TracePlotLineCache> TraceNavigator::getTracePlotLineCache()
 {
     return tracePlotLineCache;
 }
+
+const CommentModel *TraceNavigator::getCommentModel() const
+{
+    return commentModel;
+}
+
+bool TraceNavigator::existChangesToCommit() const
+{
+    return changesToCommitExist;
+}
+
+void TraceNavigator::traceFileModified()
+{
+    changesToCommitExist = true;
+}
diff --git a/DRAMSys/traceAnalyzer/presentation/tracenavigator.h b/DRAMSys/traceAnalyzer/presentation/tracenavigator.h
index 28bc8af7..f8a89bf1 100644
--- a/DRAMSys/traceAnalyzer/presentation/tracenavigator.h
+++ b/DRAMSys/traceAnalyzer/presentation/tracenavigator.h
@@ -43,10 +43,10 @@
 #include "data/tracedb.h"
 #include "businessObjects/generalinfo.h"
 #include "businessObjects/transaction.h"
-#include "businessObjects/comment.h"
 #include "memory"
 
 class TracePlotLineCache;
+class CommentModel;
 
 /*  Class to navigate through a tracefile
  *
@@ -56,10 +56,9 @@ class TracePlotLineCache;
 class TraceNavigator : public QObject
 {
     Q_OBJECT
-    using CommentMap = std::map<traceTime, Comment>;
 
 public:
-    TraceNavigator(QString path, QObject *parent = 0);
+    TraceNavigator(QString path, CommentModel *commentModel, QObject *parent = 0);
     ~TraceNavigator();
 
     traceTime CurrentTraceTime() const
@@ -111,23 +110,22 @@ public:
     bool transactionIsSelected(const std::shared_ptr<Transaction> &Transaction)
     const;
 
-    void insertComment(const Comment &comment);
-    const CommentMap &getComments()
-    {
-        return comments;
-    }
-    void removeCommentAtTime(traceTime time);
-
     void commitChangesToDB();
     void refreshData();
 
     std::shared_ptr<TracePlotLineVector> getTracePlotLines();
     std::shared_ptr<TracePlotLineCache> getTracePlotLineCache();
 
+    const CommentModel *getCommentModel() const;
+
+    bool existChangesToCommit() const;
+
 Q_SIGNALS:
     void currentTraceTimeChanged();
     void selectedTransactionsChanged();
-    void commentsChanged();
+
+public Q_SLOTS:
+    void traceFileModified();
 
 private:
     TraceDB traceFile;
@@ -136,7 +134,9 @@ private:
     //components drawing the tracefile center around that time
     traceTime currentTraceTime = 0;
     std::vector<std::shared_ptr<Transaction>> selectedTransactions;
-    CommentMap comments;
+
+    CommentModel *commentModel;
+
     void getCommentsFromDB();
     bool changesToCommitExist;
 
diff --git a/DRAMSys/traceAnalyzer/presentation/traceplot.cpp b/DRAMSys/traceAnalyzer/presentation/traceplot.cpp
index fef381a1..c6d4133e 100644
--- a/DRAMSys/traceAnalyzer/presentation/traceplot.cpp
+++ b/DRAMSys/traceAnalyzer/presentation/traceplot.cpp
@@ -55,6 +55,7 @@
 #include "traceplot.h"
 #include "gototimedialog.h"
 #include "tracedrawing.h"
+#include "businessObjects/commentmodel.h"
 #include "util/engineeringScaleDraw.h"
 #include "util/clkgrid.h"
 #include "util/customlabelscaledraw.h"
@@ -184,12 +185,24 @@ void TracePlot::setUpContextMenu()
     contextMenu->addActions({showQueryEditor, insertComment, exportToPdf, toggleCollapsedState});
 }
 
-void TracePlot::init(TraceNavigator *navigator, QScrollBar *scrollBar)
+void TracePlot::init(TraceNavigator *navigator, QScrollBar *scrollBar, CommentModel *commentModel)
 {
     Q_ASSERT(isInitialized == false);
     isInitialized = true;
 
     this->scrollBar = scrollBar;
+    this->commentModel = commentModel;
+
+    installEventFilter(commentModel);
+
+    QObject::connect(commentModel, &CommentModel::dataChanged,
+                     this, &TracePlot::commentsChanged);
+
+    QObject::connect(commentModel, &CommentModel::rowsRemoved,
+                     this, &TracePlot::commentsChanged);
+
+    QObject::connect(commentModel->selectionModel(), &QItemSelectionModel::selectionChanged,
+                     this, &TracePlot::commentsChanged);
 
     this->navigator = navigator;
     connectNavigatorQ_SIGNALS();
@@ -216,8 +229,6 @@ void TracePlot::connectNavigatorQ_SIGNALS()
                      SLOT(currentTraceTimeChanged()));
     QObject::connect(navigator, SIGNAL(selectedTransactionsChanged()), this,
                      SLOT(selectedTransactionsChanged()));
-    QObject::connect(navigator, SIGNAL(commentsChanged()), this,
-                     SLOT(commentsChanged()));
 }
 
 void TracePlot::setUpDrawingProperties()
@@ -343,16 +354,23 @@ Timespan TracePlot::GetCurrentTimespan()
 
 void TracePlot::getAndDrawComments()
 {
-    for (const auto &pair : navigator->getComments()) {
-        const Comment &comment = pair.second;
-        QwtPlotMarker *maker = new QwtPlotMarker();
-        maker->setLabel(comment.Text());
-        maker->setLabelOrientation(Qt::Vertical);
-        maker->setLabelAlignment(Qt::AlignLeft | Qt::AlignBottom);
-        maker->setXValue(static_cast<double>(comment.Time()));
-        maker->setLineStyle(QwtPlotMarker::LineStyle::VLine);
-        maker->setLinePen(QColor(Qt::blue), 2);
-        maker->attach(this);
+    QList<QModelIndex> selectedRows = commentModel->selectionModel()->selectedRows();
+
+    for (int row = 0; row < commentModel->rowCount(); row++)
+    {
+        QModelIndex timeIndex = commentModel->index(row, static_cast<int>(CommentModel::Column::Time));
+        QModelIndex textIndex = commentModel->index(row, static_cast<int>(CommentModel::Column::Comment));
+
+        bool selected = std::find(selectedRows.begin(), selectedRows.end(), commentModel->index(row, 0)) != selectedRows.end();
+
+        QwtPlotMarker *marker = new QwtPlotMarker();
+        marker->setLabel(textIndex.data().toString());
+        marker->setLabelOrientation(Qt::Vertical);
+        marker->setLabelAlignment(Qt::AlignLeft | Qt::AlignBottom);
+        marker->setXValue(static_cast<double>(timeIndex.data(Qt::UserRole).toLongLong()));
+        marker->setLineStyle(QwtPlotMarker::LineStyle::VLine);
+        marker->setLinePen(QColor(selected ? Qt::red : Qt::blue), 2);
+        marker->attach(this);
     }
 }
 
@@ -541,13 +559,7 @@ void TracePlot::on_deselectAll()
 void TracePlot::on_insertComment()
 {
     traceTime time = invTransform(xBottom, contextMenuMouseDown.x());
-    bool ok;
-    QString text = QInputDialog::getText(this, QString("Insert comment"),
-                                         QString("Insert comment at ") + prettyFormatTime(time), QLineEdit::Normal,
-                                         QString(), &ok);
-    if (ok) {
-        navigator->insertComment(Comment(time, text));
-    }
+    commentModel->addComment(time);
 }
 
 void TracePlot::on_goToTime()
@@ -646,9 +658,13 @@ bool TracePlot::eventFilter(QObject *object, QEvent *event)
                     mouseDownData.mouseIsDownForDragging = true;
                     canvas()->setCursor(Qt::ClosedHandCursor);
                     SelectTransaction(mouseEvent->x(), mouseEvent->y());
+                    SelectComment(mouseEvent->x());
                 }
                 return true;
             } else if (mouseEvent->button() == Qt::RightButton) {
+                // Also select comments to make it more obvious.
+                SelectComment(mouseEvent->x());
+
                 openContextMenu(this->canvas()->mapToGlobal(mouseEvent->pos()),
                                 mouseEvent->pos());
                 return true;
@@ -704,7 +720,7 @@ bool TracePlot::eventFilter(QObject *object, QEvent *event)
     return false;
 }
 
-void TracePlot::SelectTransaction(int x, int y)
+void TracePlot::SelectTransaction(int x, int y) const
 {
     double yVal = invTransform(yLeft, y);
     traceTime time = invTransform(xBottom, x);
@@ -717,10 +733,35 @@ void TracePlot::SelectTransaction(int x, int y)
     }
 }
 
+void TracePlot::SelectComment(int x) const
+{
+    Timespan timespan = hoveredTimespan(x);
+    QModelIndex index = commentModel->hoveredComment(timespan);
+
+    if (!index.isValid())
+        return;
+
+    if (keyPressData.ctrlPressed)
+        commentModel->selectionModel()->setCurrentIndex(index, QItemSelectionModel::Toggle | QItemSelectionModel::Rows);
+    else
+        commentModel->selectionModel()->setCurrentIndex(index, QItemSelectionModel::ClearAndSelect | QItemSelectionModel::Rows);
+}
+
+Timespan TracePlot::hoveredTimespan(int x) const
+{
+    traceTime time = invTransform(xBottom, x);
+    traceTime offset = 0.01 * zoomLevel;
+
+    return Timespan(time - offset, time + offset);
+}
+
 void TracePlot::openContextMenu(const QPoint &pos, const QPoint &mouseDown)
 {
     contextMenuMouseDown = mouseDown;
-    contextMenu->exec(pos);
+    Timespan timespan = hoveredTimespan(mouseDown.x());
+
+    if (commentModel->hoveredComment(timespan).isValid())
+        commentModel->openContextMenu();
+    else
+        contextMenu->exec(pos);
 }
-
-
diff --git a/DRAMSys/traceAnalyzer/presentation/traceplot.h b/DRAMSys/traceAnalyzer/presentation/traceplot.h
index 2676988d..bea93693 100644
--- a/DRAMSys/traceAnalyzer/presentation/traceplot.h
+++ b/DRAMSys/traceAnalyzer/presentation/traceplot.h
@@ -63,6 +63,7 @@
 class TracePlotMouseLabel;
 class CustomLabelScaleDraw;
 class ToggleCollapsedAction;
+class CommentModel;
 
 class TracePlot : public QwtPlot
 {
@@ -71,7 +72,7 @@ class TracePlot : public QwtPlot
 
 public:
     TracePlot(QWidget *parent = NULL);
-    void init(TraceNavigator *navigator, QScrollBar *scrollBar);
+    void init(TraceNavigator *navigator, QScrollBar *scrollBar, CommentModel *commentModel);
     Timespan GetCurrentTimespan();
     traceTime ZoomLevel() const
     {
@@ -97,6 +98,7 @@ Q_SIGNALS:
     void tracePlotZoomChanged();
     void tracePlotLinesChanged();
     void colorGroupingChanged(ColorGrouping colorgrouping);
+    // void editComment
 
 private Q_SLOTS:
     void on_executeQuery();
@@ -129,6 +131,7 @@ private:
     QMenu *contextMenu;
     QScrollBar *scrollBar;
     CustomLabelScaleDraw *customLabelScaleDraw;
+    CommentModel *commentModel;
 
     void setUpTracePlotItem();
     void setUpDrawingProperties();
@@ -186,7 +189,10 @@ private:
 
     void openContextMenu(const QPoint &pos, const QPoint &mouseDown);
     QPoint contextMenuMouseDown;
-    void SelectTransaction(int x, int y);
+    void SelectTransaction(int x, int y) const;
+    void SelectComment(int x) const;
+    //const std::vector<std::shared_ptr<Comment>> hoveredComments(traceTime time) const;
+    Timespan hoveredTimespan(int x) const;
     void keyPressEvent(QKeyEvent *keyPressedEvent);
     void keyReleaseEvent(QKeyEvent *keyReleasedEvent);
 
diff --git a/DRAMSys/traceAnalyzer/presentation/tracescroller.cpp b/DRAMSys/traceAnalyzer/presentation/tracescroller.cpp
index ae9906a1..12d34018 100644
--- a/DRAMSys/traceAnalyzer/presentation/tracescroller.cpp
+++ b/DRAMSys/traceAnalyzer/presentation/tracescroller.cpp
@@ -62,6 +62,17 @@ void TraceScroller::init(TraceNavigator *navigator, TracePlot *tracePlot)
     this -> navigator = navigator;
     connectNavigatorQ_SIGNALS();
 
+    const CommentModel *commentModel = navigator->getCommentModel();
+
+    QObject::connect(commentModel, &CommentModel::dataChanged,
+                     this, &TraceScroller::commentsChanged);
+
+    QObject::connect(commentModel, &CommentModel::rowsRemoved,
+                     this, &TraceScroller::commentsChanged);
+
+    QObject::connect(commentModel->selectionModel(), &QItemSelectionModel::selectionChanged,
+                     this, &TraceScroller::commentsChanged);
+
     setUpDrawingProperties();
     setUpAxis();
     setUpTracePlotItem();
@@ -119,8 +130,7 @@ void TraceScroller::connectNavigatorQ_SIGNALS()
 {
     QObject::connect(navigator, SIGNAL(currentTraceTimeChanged()), this,
                      SLOT(currentTraceTimeChanged()));
-    QObject::connect(navigator, SIGNAL(commentsChanged()), this,
-                     SLOT(commentsChanged()));
+
     QObject::connect(navigator, SIGNAL(selectedTransactionsChanged()), this,
                      SLOT(selectedTransactionsChanged()));
 }
@@ -147,12 +157,19 @@ Timespan TraceScroller::GetCurrentTimespan()
 
 void TraceScroller::getAndDrawComments()
 {
-    for (const auto &pair : navigator->getComments()) {
-        const Comment &comment = pair.second;
+    const CommentModel *commentModel = navigator->getCommentModel();
+    QList<QModelIndex> selectedRows = commentModel->selectionModel()->selectedRows();
+
+    for (int row = 0; row < commentModel->rowCount(); row++)
+    {
+        QModelIndex timeIndex = commentModel->index(row, static_cast<int>(CommentModel::Column::Time));
+
+        bool selected = std::find(selectedRows.begin(), selectedRows.end(), commentModel->index(row, 0)) != selectedRows.end();
+
         QwtPlotMarker *maker = new QwtPlotMarker();
-        maker->setXValue(static_cast<double>(comment.Time()));
+        maker->setXValue(static_cast<double>(timeIndex.data(Qt::UserRole).toLongLong()));
         maker->setLineStyle(QwtPlotMarker::LineStyle::VLine);
-        maker->setLinePen(QColor(Qt::blue), 2);
+        maker->setLinePen(QColor(selected ? Qt::red : Qt::blue), 2);
         maker->attach(this);
     }
 }
diff --git a/DRAMSys/traceAnalyzer/presentation/tracescroller.h b/DRAMSys/traceAnalyzer/presentation/tracescroller.h
index 8a5d8583..310d46d1 100644
--- a/DRAMSys/traceAnalyzer/presentation/tracescroller.h
+++ b/DRAMSys/traceAnalyzer/presentation/tracescroller.h
@@ -60,7 +60,6 @@ private:
     void setUpAxis();
     void connectNavigatorQ_SIGNALS();
 
-
     void getAndDrawComments();
     QwtPlotZoneItem *canvasClip;
     traceTime zoomLevel;
diff --git a/DRAMSys/traceAnalyzer/traceanalyzer.cpp b/DRAMSys/traceAnalyzer/traceanalyzer.cpp
index 02103ce7..dda259b9 100644
--- a/DRAMSys/traceAnalyzer/traceanalyzer.cpp
+++ b/DRAMSys/traceAnalyzer/traceanalyzer.cpp
@@ -37,12 +37,13 @@
  */
 
 #include "traceanalyzer.h"
-#include "ui_traceanalyzer.h"
+#include "QMessageBox"
 #include "tracefiletab.h"
+#include "ui_traceanalyzer.h"
+#include <QCloseEvent>
+#include <QDateTime>
 #include <QFileDialog>
 #include <QFileInfo>
-#include <QDateTime>
-#include "QMessageBox"
 #include <iostream>
 
 void TraceAnalyzer::setUpStatusBar()
@@ -64,13 +65,6 @@ TraceAnalyzer::TraceAnalyzer(QWidget *parent) :
     ui(new Ui::TraceAnalyzer)
 {
     setUpGui();
-    // Disable actions except for "Open" until some file is open.
-    ui->actionReload_all->setEnabled(false);
-    ui->actionSaveChangesToDB->setEnabled(false);
-    ui->actionExportAsVCD->setEnabled(false);
-    ui->actionClose_all->setEnabled(false);
-    ui->actionTest->setEnabled(false);
-    ui->actionMetrics->setEnabled(false);
 }
 
 TraceAnalyzer::TraceAnalyzer(QSet<QString> paths, StartupOption option,
@@ -119,41 +113,43 @@ void TraceAnalyzer::openTracefile(const QString &path)
     ui->traceFileTabs->addTab(tab, QFileInfo(path).baseName());
     openedTraceFiles.insert(path);
 
-    // Enable actions
-    ui->actionReload_all->setEnabled(true);
-    ui->actionSaveChangesToDB->setEnabled(true);
-
-    if (PythonCaller::instance().vcdExportDependenciesAvailable())
-        ui->actionExportAsVCD->setEnabled(true);
-
-    ui->actionClose_all->setEnabled(true);
-    ui->actionTest->setEnabled(true);
-    ui->actionMetrics->setEnabled(true);
-
     statusLabel->clear();
 }
 
+void TraceAnalyzer::on_menuFile_aboutToShow()
+{
+    ui->actionOpen->setEnabled(true);
+
+    bool tabsOpen = ui->traceFileTabs->count() > 0;
+    bool exportAsVcdAvailable = PythonCaller::instance().vcdExportDependenciesAvailable();
+
+    ui->actionReload_all->setEnabled(tabsOpen);
+    ui->actionSaveChangesToDB->setEnabled(tabsOpen);
+    ui->actionExportAsVCD->setEnabled(tabsOpen && exportAsVcdAvailable);
+    ui->actionClose_all->setEnabled(tabsOpen);
+    ui->actionTest->setEnabled(tabsOpen);
+    ui->actionMetrics->setEnabled(tabsOpen);
+}
+
 void TraceAnalyzer::on_traceFileTabs_tabCloseRequested(int index)
 {
     TraceFileTab *traceFileTab = static_cast<TraceFileTab *>
                                  (ui->traceFileTabs->widget(index));
-    openedTraceFiles.remove(traceFileTab->getPathToTraceFile());
-    ui->traceFileTabs->removeTab(index);
-    delete traceFileTab;
+
+    if (traceFileTab->close())
+    {
+        openedTraceFiles.remove(traceFileTab->getPathToTraceFile());
+        ui->traceFileTabs->removeTab(index);
+        delete traceFileTab;
+    }
 }
 
 void TraceAnalyzer::on_actionClose_all_triggered()
 {
-    while (ui->traceFileTabs->count())
-        on_traceFileTabs_tabCloseRequested(0);
-
-    // All files closed. Disable actions except for "Open".
-    ui->actionReload_all->setEnabled(false);
-    ui->actionSaveChangesToDB->setEnabled(false);
-    ui->actionExportAsVCD->setEnabled(false);
-    ui->actionClose_all->setEnabled(false);
-    ui->actionTest->setEnabled(false);
-    ui->actionMetrics->setEnabled(false);
+    for (unsigned int i = ui->traceFileTabs->count(); i--;)
+    {
+        on_traceFileTabs_tabCloseRequested(i);
+    }
 
     statusLabel->clear();
 }
@@ -163,23 +159,24 @@ void TraceAnalyzer::on_actionReload_all_triggered()
     TraceFileTab *traceFileTab;
 
     // Remove all tabs
-    int tabIndex = 0;
-    while (ui->traceFileTabs->count() != 0) {
+    for (unsigned int i = ui->traceFileTabs->count(); i--;)
+    {
         traceFileTab = static_cast<TraceFileTab *>(ui->traceFileTabs->widget(0));
-        std::cout << "Closing tab #" << tabIndex << " \"" <<
-                  traceFileTab->getPathToTraceFile().toStdString() << "\"" << std::endl;
+        std::cout << "Closing tab #" << i << " \"" << traceFileTab->getPathToTraceFile().toStdString() << "\""
+                  << std::endl;
+
+        if (!traceFileTab->close())
+            return;
 
         ui->traceFileTabs->removeTab(0);
         delete traceFileTab;
-
-        tabIndex++;
     }
 
     QList<QString> list = openedTraceFiles.toList();
     qSort(list);
 
     // Recreate all tabs
-    tabIndex = 0;
+    int tabIndex = 0;
     for (auto path : list) {
         std::cout << "Reopening tab# " << tabIndex << " \"" << path.toStdString() <<
                   "\"" << std::endl;
@@ -231,3 +228,18 @@ void TraceAnalyzer::on_actionMetrics_triggered()
     evaluationTool.activateWindow();
     evaluationTool.showAndEvaluateMetrics(openedTraceFiles.toList());
 }
+
+void TraceAnalyzer::closeEvent(QCloseEvent *event)
+{
+    for (unsigned int i = 0; i < ui->traceFileTabs->count(); i++)
+    {
+        QWidget *tab = ui->traceFileTabs->widget(i);
+        if (!tab->close())
+        {
+            event->ignore();
+            return;
+        }
+    }
+
+    event->accept();
+}
diff --git a/DRAMSys/traceAnalyzer/traceanalyzer.h b/DRAMSys/traceAnalyzer/traceanalyzer.h
index f28ae7e2..e6916862 100644
--- a/DRAMSys/traceAnalyzer/traceanalyzer.h
+++ b/DRAMSys/traceAnalyzer/traceanalyzer.h
@@ -67,20 +67,24 @@ public:
     void setUpStatusBar();
     void setUpGui();
 
+protected:
+    void closeEvent(QCloseEvent *event) override;
+
 private:
     void openTracefile(const QString &path);
     QLabel *statusLabel;
     QSet<QString> openedTraceFiles;
 
 private Q_SLOTS:
+    void on_menuFile_aboutToShow();
+    void on_traceFileTabs_tabCloseRequested(int index);
+
     void on_actionOpen_triggered();
     void on_actionReload_all_triggered();
     void on_actionSaveChangesToDB_triggered();
     void on_actionExportAsVCD_triggered();
-    void on_traceFileTabs_tabCloseRequested(int index);
     void on_actionClose_all_triggered();
     void on_actionTest_triggered();
-
     void on_actionMetrics_triggered();
 
 public Q_SLOTS:
diff --git a/DRAMSys/traceAnalyzer/tracefiletab.cpp b/DRAMSys/traceAnalyzer/tracefiletab.cpp
index 36c95509..80da307a 100644
--- a/DRAMSys/traceAnalyzer/tracefiletab.cpp
+++ b/DRAMSys/traceAnalyzer/tracefiletab.cpp
@@ -37,37 +37,37 @@
  */
 
 #include "tracefiletab.h"
-#include "ui_tracefiletab.h"
-#include "queryeditor.h"
 #include "QFileInfo"
-#include "qmessagebox.h"
+#include "businessObjects/commentmodel.h"
+#include "businessObjects/configmodels.h"
 #include "businessObjects/pythoncaller.h"
-#include <iostream>
-#include <QStandardItemModel>
-#include <QString>
-#include <QItemDelegate>
-#include <QFileDialog>
-#include <QtConcurrent/QtConcurrent>
-#include <QTextStream>
-#include <QDebug>
-#include "qwt_plot_histogram.h"
-#include "qwt_plot_curve.h"
-#include "qwt_plot_layout.h"
-#include "qwt_scale_draw.h"
-#include "qwt_scale_widget.h"
+#include "presentation/traceselector.h"
+#include "qmessagebox.h"
+#include "queryeditor.h"
 #include "qwt_legend.h"
+#include "qwt_plot_curve.h"
+#include "qwt_plot_histogram.h"
+#include "qwt_plot_layout.h"
 #include "qwt_plot_magnifier.h"
 #include "qwt_plot_panner.h"
-#include "presentation/traceselector.h"
-#include "businessObjects/configmodels.h"
+#include "qwt_scale_draw.h"
+#include "qwt_scale_widget.h"
+#include "ui_tracefiletab.h"
+#include <QDebug>
+#include <QFileDialog>
+#include <QItemDelegate>
+#include <QMessageBox>
+#include <QStandardItemModel>
+#include <QString>
+#include <QTextStream>
+#include <QtConcurrent/QtConcurrent>
+#include <iostream>
 
-#include <math.h>
-
-TraceFileTab::TraceFileTab(QWidget *parent, const QString &path) :
-    QWidget(parent), ui(new Ui::TraceFileTab), navigator(new TraceNavigator(path, this)),
-    mcConfigModel(new McConfigModel(navigator->TraceFile(), this)),
-    memSpecModel(new MemSpecModel(navigator->TraceFile(), this)),
-    savingChangesToDB(false)
+TraceFileTab::TraceFileTab(QWidget *parent, const QString &path)
+    : QWidget(parent), ui(new Ui::TraceFileTab), commentModel(new CommentModel(this)),
+      navigator(new TraceNavigator(path, commentModel, this)),
+      mcConfigModel(new McConfigModel(navigator->TraceFile(), this)),
+      memSpecModel(new MemSpecModel(navigator->TraceFile(), this)), savingChangesToDB(false)
 {
     ui->setupUi(this);
     this->path = path;
@@ -79,6 +79,7 @@ TraceFileTab::TraceFileTab(QWidget *parent, const QString &path) :
     setUpFileWatcher(path);
     setUpTraceplotScrollbar();
     setUpTraceSelector();
+    setUpCommentView();
 
     ui->fileDescriptionEdit->setPlainText(
         navigator->GeneralTraceInfo().description);
@@ -132,7 +133,7 @@ void TraceFileTab::setUpTraceplotScrollbar()
 
 void TraceFileTab::initNavigatorAndItsDependentWidgets(QString path)
 {
-    ui->traceplot->init(navigator, ui->traceplotScrollbar);
+    ui->traceplot->init(navigator, ui->traceplotScrollbar, commentModel);
 
     ui->traceScroller->init(navigator, ui->traceplot);
     connect(this, SIGNAL(colorGroupingChanged(ColorGrouping)),
@@ -140,7 +141,6 @@ void TraceFileTab::initNavigatorAndItsDependentWidgets(QString path)
 
     ui->selectedTransactionTree->init(navigator);
     //ui->debugMessages->init(navigator,ui->traceplot);
-    ui->commentTree->init(navigator);
 }
 
 void TraceFileTab::setUpFileWatcher(QString path)
@@ -158,6 +158,26 @@ void TraceFileTab::setUpTraceSelector()
     selector->init(ui->traceplot);
 }
 
+void TraceFileTab::setUpCommentView()
+{
+    ui->commentView->setModel(commentModel);
+    ui->commentView->setSelectionModel(commentModel->selectionModel());
+    ui->commentView->installEventFilter(commentModel);
+    ui->commentView->setContextMenuPolicy(Qt::CustomContextMenu);
+
+    QObject::connect(ui->commentView, &QTableView::customContextMenuRequested,
+                     commentModel, &CommentModel::openContextMenu);
+
+    QObject::connect(commentModel, &CommentModel::editTriggered, ui->commentView, [=](const QModelIndex &index){
+        ui->tabWidget->setCurrentWidget(ui->tabSelectedTrans);
+        ui->commentView->edit(index);
+        ui->commentView->scrollTo(index);
+    });
+
+    QObject::connect(ui->commentView, &QTableView::doubleClicked,
+                     commentModel, &CommentModel::rowDoubleClicked);
+}
+
 void TraceFileTab::tracefileChanged()
 {
     if (savingChangesToDB == true) {
@@ -176,6 +196,37 @@ void TraceFileTab::tracefileChanged()
     navigator->refreshData();
 }
 
+void TraceFileTab::closeEvent(QCloseEvent *event)
+{
+    if (navigator->existChangesToCommit())
+    {
+        QMessageBox saveDialog;
+        saveDialog.setWindowTitle(QFileInfo(path).baseName());
+        saveDialog.setText("The trace file has been modified.");
+        saveDialog.setInformativeText("Do you want to save your changes?<br><b>Unsaved changes will be lost.</b>");
+        saveDialog.setStandardButtons(QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel);
+        saveDialog.setDefaultButton(QMessageBox::Save);
+        saveDialog.setIcon(QMessageBox::Warning);
+        int returnCode = saveDialog.exec();
+
+        switch (returnCode)
+        {
+        case QMessageBox::Cancel:
+            event->ignore();
+            break;
+        case QMessageBox::Discard:
+            event->accept();
+            break;
+        case QMessageBox::Save:
+            commitChangesToDB();
+            event->accept();
+            break;
+        };
+    }
+    else
+        event->accept();
+}
+
 class ItemDelegate: public QItemDelegate
 {
 public:
diff --git a/DRAMSys/traceAnalyzer/tracefiletab.h b/DRAMSys/traceAnalyzer/tracefiletab.h
index 966d5784..1962088d 100644
--- a/DRAMSys/traceAnalyzer/tracefiletab.h
+++ b/DRAMSys/traceAnalyzer/tracefiletab.h
@@ -47,6 +47,8 @@
 #include "presentation/tracescroller.h"
 #include "businessObjects/configmodels.h"
 
+class CommentModel;
+
 namespace Ui {
 class TraceFileTab;
 }
@@ -62,6 +64,7 @@ public:
     void setUpFileWatcher(QString filename);
     void setUpTraceplotScrollbar();
     void setUpTraceSelector();
+    void setUpCommentView();
     void initNavigatorAndItsDependentWidgets(QString path);
     QString getPathToTraceFile()
     {
@@ -70,12 +73,17 @@ public:
     void commitChangesToDB(void);
     void exportAsVCD();
 
+protected:
+    void closeEvent(QCloseEvent *event) override;
+
 private:
     QString path;
     Ui::TraceFileTab *ui;
-    TraceNavigator *navigator;
     QFileSystemWatcher *fileWatcher;
 
+    CommentModel *commentModel;
+    TraceNavigator *navigator;
+
     QAbstractItemModel *mcConfigModel;
     QAbstractItemModel *memSpecModel;
 
diff --git a/DRAMSys/traceAnalyzer/tracefiletab.ui b/DRAMSys/traceAnalyzer/tracefiletab.ui
index 64693bdb..647a3b50 100644
--- a/DRAMSys/traceAnalyzer/tracefiletab.ui
+++ b/DRAMSys/traceAnalyzer/tracefiletab.ui
@@ -170,7 +170,7 @@
            </widget>
           </item>
           <item>
-           <widget class="CommentTreeWidget" name="commentTree">
+           <widget class="QTableView" name="commentView">
             <property name="sizePolicy">
              <sizepolicy hsizetype="Expanding" vsizetype="Minimum">
               <horstretch>2</horstretch>
@@ -189,11 +189,27 @@
               <height>16777215</height>
              </size>
             </property>
-            <column>
-             <property name="text">
-              <string notr="true">1</string>
-             </property>
-            </column>
+            <property name="editTriggers">
+             <set>QAbstractItemView::DoubleClicked|QAbstractItemView::EditKeyPressed</set>
+            </property>
+            <property name="alternatingRowColors">
+             <bool>true</bool>
+            </property>
+            <property name="selectionBehavior">
+             <enum>QAbstractItemView::SelectRows</enum>
+            </property>
+            <property name="gridStyle">
+             <enum>Qt::NoPen</enum>
+            </property>
+            <property name="sortingEnabled">
+             <bool>false</bool>
+            </property>
+            <attribute name="horizontalHeaderStretchLastSection">
+             <bool>true</bool>
+            </attribute>
+            <attribute name="verticalHeaderVisible">
+             <bool>false</bool>
+            </attribute>
            </widget>
           </item>
           <item>
@@ -402,11 +418,6 @@
    <extends>QListView</extends>
    <header>presentation/tracescroller.h</header>
   </customwidget>
-  <customwidget>
-   <class>CommentTreeWidget</class>
-   <extends>QTreeWidget</extends>
-   <header>presentation/commenttreewidget.h</header>
-  </customwidget>
   <customwidget>
    <class>SelectedTransactionTreeWidget</class>
    <extends>QTreeWidget</extends>