diff --git a/src/main/java/de/hitec/nhplus/datastorage/ConnectionBuilder.java b/src/main/java/de/hitec/nhplus/datastorage/ConnectionBuilder.java
index ea22873..82cea08 100644
--- a/src/main/java/de/hitec/nhplus/datastorage/ConnectionBuilder.java
+++ b/src/main/java/de/hitec/nhplus/datastorage/ConnectionBuilder.java
@@ -1,11 +1,17 @@
 package de.hitec.nhplus.datastorage;
 
+import org.sqlite.SQLiteConfig;
+
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.SQLException;
 
-import org.sqlite.SQLiteConfig;
-
+/**
+ * The {@link DaoFactory} allows a safe connection to the Database.
+ *
+ * @author Bernd Heidemann
+ * @version 1.0
+ */
 public class ConnectionBuilder {
 
     private static final String DB_NAME = "nursingHome.db";
@@ -13,6 +19,10 @@ public class ConnectionBuilder {
 
     private static Connection connection;
 
+    /**
+     * @return a Thread-safe {@link Connection} to the Database.
+     * @author Bernd Heidemann
+     */
     synchronized public static Connection getConnection() {
         try {
             if (ConnectionBuilder.connection == null) {
@@ -27,6 +37,11 @@ public class ConnectionBuilder {
         return ConnectionBuilder.connection;
     }
 
+    /**
+     * Closes the Connection to the Database.
+     *
+     * @author Bernd Heidemann
+     */
     synchronized public static void closeConnection() {
         try {
             if (ConnectionBuilder.connection != null) {
diff --git a/src/main/java/de/hitec/nhplus/datastorage/Dao.java b/src/main/java/de/hitec/nhplus/datastorage/Dao.java
index 172bea1..0a38d48 100644
--- a/src/main/java/de/hitec/nhplus/datastorage/Dao.java
+++ b/src/main/java/de/hitec/nhplus/datastorage/Dao.java
@@ -3,14 +3,52 @@ package de.hitec.nhplus.datastorage;
 import java.sql.SQLException;
 import java.util.List;
 
+/**
+ * {@link Dao} is the Abbreviation of Data-Access-Object.
+ * This Interface has the Basic Methods which are needed on any DAO to work as expected.
+ *
+ * @param <T> The Model for which that DAO is implemented
+ * @author Bernd Heidemann
+ * @version 1.0
+ * @implSpec The Implementations should be added to the {@link DaoFactory}
+ */
 public interface Dao<T> {
+    /**
+     * Create a Database Entry from a Model object.
+     *
+     * @param t the Model instance
+     * @author Bernd Heidemann
+     */
     void create(T t) throws SQLException;
 
+    /**
+     * Read a Database Entry to a Model object.
+     *
+     * @param id of the Element in the Database
+     * @author Bernd Heidemann
+     */
     T read(int id) throws SQLException;
 
+    /**
+     * Read all Database Entries to a {@link List} of Model objects.
+     *
+     * @author Bernd Heidemann
+     */
     List<T> readAll() throws SQLException;
 
+    /**
+     * Update the Database according to the Values of the Model object.
+     *
+     * @param t the Model instance.
+     * @author Bernd Heidemann
+     */
     void update(T t) throws SQLException;
 
-    void deleteById(int id) throws SQLException;
+    /**
+     * Delete a Database Entry.
+     *
+     * @param id of the Element in the Database.
+     * @author Bernd Heidemann
+     */
+    void delete(int id) throws SQLException;
 }
diff --git a/src/main/java/de/hitec/nhplus/datastorage/DaoFactory.java b/src/main/java/de/hitec/nhplus/datastorage/DaoFactory.java
index 08c2ba7..f4fc8dc 100644
--- a/src/main/java/de/hitec/nhplus/datastorage/DaoFactory.java
+++ b/src/main/java/de/hitec/nhplus/datastorage/DaoFactory.java
@@ -4,13 +4,28 @@ import de.hitec.nhplus.nurse.database.NurseDao;
 import de.hitec.nhplus.patient.database.PatientDao;
 import de.hitec.nhplus.treatment.database.TreatmentDao;
 
+/**
+ * The {@link DaoFactory} is a Singleton({@link DaoFactory#getInstance}) which should be used to get {@link Dao}s.
+ *
+ * @author Bernd Heidemann
+ * @version 1.0
+ */
 public class DaoFactory {
 
     private static DaoFactory instance;
 
+    /**
+     * A Private Constructor according to the Singleton Pattern.
+     *
+     * @author Bernd Heidemann
+     */
     private DaoFactory() {
     }
 
+    /**
+     * @return {@link DaoFactory}, the Singleton Instance
+     * @author Bernd Heidemann
+     */
     public static DaoFactory getInstance() {
         if (DaoFactory.instance == null) {
             DaoFactory.instance = new DaoFactory();
@@ -18,14 +33,26 @@ public class DaoFactory {
         return DaoFactory.instance;
     }
 
+    /**
+     * @return a {@link TreatmentDao}
+     * @author Bernd Heidemann
+     */
     public TreatmentDao createTreatmentDao() {
         return new TreatmentDao(ConnectionBuilder.getConnection());
     }
 
+    /**
+     * @return a {@link PatientDao}
+     * @author Bernd Heidemann
+     */
     public PatientDao createPatientDAO() {
         return new PatientDao(ConnectionBuilder.getConnection());
     }
 
+    /**
+     * @return a {@link NurseDao}
+     * @author Dominik Säume
+     */
     public NurseDao createNurseDAO() {
         return new NurseDao(ConnectionBuilder.getConnection());
     }
diff --git a/src/main/java/de/hitec/nhplus/datastorage/DaoImp.java b/src/main/java/de/hitec/nhplus/datastorage/DaoImp.java
index 632e21e..417c285 100644
--- a/src/main/java/de/hitec/nhplus/datastorage/DaoImp.java
+++ b/src/main/java/de/hitec/nhplus/datastorage/DaoImp.java
@@ -6,18 +6,43 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.List;
 
+/**
+ * The {@link DaoImp} is a Generic Base Implementation of the {@link Dao},
+ * which should fit most use cases.
+ *
+ * @param <T> The Model for which that DAO is implemented
+ * @author Bernd Heidemann
+ * @version 1.0
+ * @implSpec The Implementations should be added to the {@link DaoFactory}
+ */
 public abstract class DaoImp<T> implements Dao<T> {
     protected final Connection connection;
 
+    /**
+     * @param connection a Database Connection, which should be gotten from {@link ConnectionBuilder}
+     * @author Bernd Heidemann
+     */
     public DaoImp(Connection connection) {
         this.connection = connection;
     }
 
+    /**
+     * Creates a new Database Entry from a Model object.
+     *
+     * @param t the Model instance
+     * @author Bernd Heidemann
+     */
     @Override
     public void create(T t) throws SQLException {
         getCreateStatement(t).executeUpdate();
     }
 
+    /**
+     * Read a Database Entry to a Model object.
+     *
+     * @param id of the Element in the Database
+     * @author Bernd Heidemann
+     */
     @Override
     public T read(int id) throws SQLException {
         T object = null;
@@ -28,18 +53,35 @@ public abstract class DaoImp<T> implements Dao<T> {
         return object;
     }
 
+    /**
+     * Read all Database Entries to a {@link List} of Model objects.
+     *
+     * @author Bernd Heidemann
+     */
     @Override
     public List<T> readAll() throws SQLException {
         return getListFromResultSet(getReadAllStatement().executeQuery());
     }
 
+    /**
+     * Update the Database according to the Values of the Model object.
+     *
+     * @param t the Model instance.
+     * @author Bernd Heidemann
+     */
     @Override
     public void update(T t) throws SQLException {
         getUpdateStatement(t).executeUpdate();
     }
 
+    /**
+     * Delete a Database Entry.
+     *
+     * @param id of the Element in the Database.
+     * @author Bernd Heidemann
+     */
     @Override
-    public void deleteById(int id) throws SQLException {
+    public void delete(int id) throws SQLException {
         getDeleteStatement(id).executeUpdate();
     }
 
diff --git a/src/main/java/de/hitec/nhplus/patient/AllPatientController.java b/src/main/java/de/hitec/nhplus/patient/AllPatientController.java
index e9df51d..1e99995 100644
--- a/src/main/java/de/hitec/nhplus/patient/AllPatientController.java
+++ b/src/main/java/de/hitec/nhplus/patient/AllPatientController.java
@@ -188,7 +188,7 @@ public class AllPatientController {
         Patient selectedItem = this.tableView.getSelectionModel().getSelectedItem();
         if (selectedItem != null) {
             try {
-                DaoFactory.getInstance().createPatientDAO().deleteById(selectedItem.getId());
+                DaoFactory.getInstance().createPatientDAO().delete(selectedItem.getId());
                 this.tableView.getItems().remove(selectedItem);
             } catch (SQLException exception) {
                 exception.printStackTrace();
diff --git a/src/main/java/de/hitec/nhplus/treatment/AllTreatmentController.java b/src/main/java/de/hitec/nhplus/treatment/AllTreatmentController.java
index fd982ae..c0f01c3 100644
--- a/src/main/java/de/hitec/nhplus/treatment/AllTreatmentController.java
+++ b/src/main/java/de/hitec/nhplus/treatment/AllTreatmentController.java
@@ -5,7 +5,6 @@ import de.hitec.nhplus.datastorage.DaoFactory;
 import de.hitec.nhplus.patient.Patient;
 import de.hitec.nhplus.patient.database.PatientDao;
 import de.hitec.nhplus.treatment.database.TreatmentDao;
-import javafx.beans.property.SimpleIntegerProperty;
 import javafx.beans.property.SimpleStringProperty;
 import javafx.collections.FXCollections;
 import javafx.collections.ObservableList;
@@ -147,7 +146,7 @@ public class AllTreatmentController {
         Treatment t = this.treatments.remove(index);
         TreatmentDao dao = DaoFactory.getInstance().createTreatmentDao();
         try {
-            dao.deleteById(t.getId());
+            dao.delete(t.getId());
         } catch (SQLException exception) {
             exception.printStackTrace();
         }