diff --git a/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/CPURta.java b/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/CPURta.java
index 2c0a1a7..d5a0fa2 100644
--- a/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/CPURta.java
+++ b/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/CPURta.java
@@ -76,7 +76,14 @@
 	 * Constructor only for testing the class
 	 */
 	public CPURta() {
-		this.setModel(AmaltheaLoader.loadFromFile(this.inputFile));
+		final Logger log = Logger.getLogger(CPURta.class);
+		final Amalthea pModel = AmaltheaLoader.loadFromFile(this.inputFile);
+		if (pModel == null) {
+			log.error("Model is empty. Please check the model path.");
+			return;
+		} else {
+			this.setModel(AmaltheaLoader.loadFromFile(this.inputFile));
+		}
 		this.setTRT(this.getDefaultTRT(this.getModel()));
 		this.setIA(this.getDefaultIAMapping());
 		this.setPUl(CommonUtils.getPUs(this.getModel()));
diff --git a/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/Contention.java b/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/Contention.java
index c68bf5d..b31da13 100644
--- a/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/Contention.java
+++ b/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/Contention.java
@@ -20,7 +20,6 @@
 import java.util.Set;
 import java.util.stream.Collectors;
 
-import org.eclipse.app4mc.gsoc_rta.CommonUtils;
 import org.eclipse.app4mc.amalthea.model.Amalthea;
 import org.eclipse.app4mc.amalthea.model.CallSequenceItem;
 import org.eclipse.app4mc.amalthea.model.InterProcessStimulus;
@@ -55,7 +54,11 @@
 	public Contention(final int[] iap, final Amalthea modelp) {
 		this.ia = iap;
 		this.model = modelp;
-		this.flagArray = new int[iap.length];
+		if (iap == null) {
+			this.flagArray = null;
+		} else {
+			this.flagArray = new int[iap.length];
+		}
 	}
 
 	/**
@@ -139,6 +142,7 @@
 				}
 			}
 
+			@SuppressWarnings("unchecked")
 			final List<Label>[] aryofLabelList = new ArrayList[2];
 			aryofLabelList[0] = readLabelList;
 			aryofLabelList[1] = writeLabelList;
@@ -641,4 +645,4 @@
 
 		return contentionTime;
 	}
-}
+}
\ No newline at end of file
diff --git a/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/E2ELatency.java b/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/E2ELatency.java
index 69fa8ca..055ecd8 100644
--- a/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/E2ELatency.java
+++ b/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/E2ELatency.java
@@ -13,6 +13,7 @@
  *******************************************************************************/
 package org.eclipse.app4mc.gsoc_rta;
 
+import java.io.File;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.util.ArrayList;
@@ -48,6 +49,7 @@
  * 				This class is to analyze End-to-End latency with the help of CPURta class.
  */
 public class E2ELatency {
+	public final File inputFile = new File("model-input/WATERS19_release/ChallengeModel_release.amxmi");
 	public CPURta cpurta = new CPURta();
 	public static final int[] defaultIAMapping = new int[] { 4, 1, 1, 3, 4, 0, 3, 3, 3, 0, 6, 2, 5, 6 };
 	public static void main(String[] args) {
@@ -60,6 +62,10 @@
 	public void run() {
 		final Logger log = Logger.getLogger(E2ELatency.class);
 		this.setCPURta(this.cpurta);
+		if (this.cpurta.getModel() == null) {
+			log.debug("Model is empty. Please check the model path.");
+			return ;
+		}
 		final EList<EventChain> ecList = this.cpurta.getModel().getConstraintsModel().getEventChains();
 		for (int i = 0; i < ecList.size(); i++) {
 			log.debug(" ----- " + "Chain " + (i+1) + " ----- ");
@@ -100,9 +106,10 @@
 	 */
 	public void setCPURta(final CPURta cpurta) {
 		final Logger log = Logger.getLogger(E2ELatency.class);
-		cpurta.setModel(AmaltheaLoader.loadFromFile(cpurta.inputFile));
+		cpurta.setModel(AmaltheaLoader.loadFromFile(this.inputFile));
 		if (cpurta.getModel() == null) {
-			log.debug("NOT GOOD!");
+			log.debug("Model is empty. Please check the model path.");
+			return ;
 		}
 		cpurta.setTRT(cpurta.getDefaultTRT(cpurta.getModel()));
 		cpurta.setIA(defaultIAMapping);
diff --git a/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/RTARuntimeUtil.java b/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/RTARuntimeUtil.java
index da619aa..7d19a19 100644
--- a/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/RTARuntimeUtil.java
+++ b/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/RTARuntimeUtil.java
@@ -296,12 +296,10 @@
 		if (executionCase.equals(TimeType.WCET)) {
 			readLatency = pu.getAccessElements().get(0).getReadLatency().getUpperBound();
 			writeLatency = pu.getAccessElements().get(0).getWriteLatency().getUpperBound();
-		}
-		else if (executionCase.equals(TimeType.BCET)) {
+		} else if (executionCase.equals(TimeType.BCET)) {
 			readLatency = pu.getAccessElements().get(0).getReadLatency().getLowerBound();
 			writeLatency = pu.getAccessElements().get(0).getWriteLatency().getLowerBound();
-		}
-		else {
+		} else {
 			readLatency = pu.getAccessElements().get(0).getReadLatency().getAverage();
 			writeLatency = pu.getAccessElements().get(0).getWriteLatency().getAverage();
 		}
@@ -349,21 +347,23 @@
 		final double freq = AmaltheaServices.convertToHertz(pu.getFrequencyDomain().getDefaultValue()).longValue();
 		double readLatency = 0;
 		double writeLatency = 0;
-		if (executionCase.equals(TimeType.WCET)) {
-			readLatency = pu.getAccessElements().get(0).getReadLatency().getUpperBound();
-			writeLatency = pu.getAccessElements().get(0).getWriteLatency().getUpperBound();
-		}
-		else if (executionCase.equals(TimeType.BCET)) {
-			readLatency = pu.getAccessElements().get(0).getReadLatency().getLowerBound();
-			writeLatency = pu.getAccessElements().get(0).getWriteLatency().getLowerBound();
-		}
-		else {
-			readLatency = pu.getAccessElements().get(0).getReadLatency().getAverage();
-			writeLatency = pu.getAccessElements().get(0).getWriteLatency().getAverage();
+		if (pu.getAccessElements().size() == 0) {
+			readLatency = 30; // Default value will be assigned
+			writeLatency = 30; // Default value of will be assigned
+		} else {
+			if (executionCase.equals(TimeType.WCET)) {
+				readLatency = pu.getAccessElements().get(0).getReadLatency().getUpperBound();
+				writeLatency = pu.getAccessElements().get(0).getWriteLatency().getUpperBound();
+			} else if (executionCase.equals(TimeType.BCET)) {
+				readLatency = pu.getAccessElements().get(0).getReadLatency().getLowerBound();
+				writeLatency = pu.getAccessElements().get(0).getWriteLatency().getLowerBound();
+			} else {
+				readLatency = pu.getAccessElements().get(0).getReadLatency().getAverage();
+				writeLatency = pu.getAccessElements().get(0).getWriteLatency().getAverage();
+			}
 		}
 		/* Read & Write Memory Access Time */
 		result = result.add(getRunnableMemoryAccessTime(runnable, freq, readLatency, writeLatency));
-		
 		/* Execution (Ticks): */
 		final List<Ticks> ticksList = SoftwareUtil.getTicks(runnable, null);
 		for (final Ticks t : ticksList) {
@@ -390,17 +390,20 @@
 		final List<Runnable> runnableList = SoftwareUtil.getRunnableList(task, null);
 		double readLatency = 0;
 		double writeLatency = 0;
-		if (executionCase.equals(TimeType.WCET)) {
-			readLatency = pu.getAccessElements().get(0).getReadLatency().getUpperBound();
-			writeLatency = pu.getAccessElements().get(0).getWriteLatency().getUpperBound();
-		}
-		else if (executionCase.equals(TimeType.BCET)) {
-			readLatency = pu.getAccessElements().get(0).getReadLatency().getLowerBound();
-			writeLatency = pu.getAccessElements().get(0).getWriteLatency().getLowerBound();
-		}
-		else {
-			readLatency = pu.getAccessElements().get(0).getReadLatency().getAverage();
-			writeLatency = pu.getAccessElements().get(0).getWriteLatency().getAverage();
+		if (pu.getAccessElements().size() == 0) {
+			readLatency = 30; // Default value will be assigned
+			writeLatency = 30; // Default value of will be assigned
+		} else {
+			if (executionCase.equals(TimeType.WCET)) {
+				readLatency = pu.getAccessElements().get(0).getReadLatency().getUpperBound();
+				writeLatency = pu.getAccessElements().get(0).getWriteLatency().getUpperBound();
+			} else if (executionCase.equals(TimeType.BCET)) {
+				readLatency = pu.getAccessElements().get(0).getReadLatency().getLowerBound();
+				writeLatency = pu.getAccessElements().get(0).getWriteLatency().getLowerBound();
+			} else {
+				readLatency = pu.getAccessElements().get(0).getReadLatency().getAverage();
+				writeLatency = pu.getAccessElements().get(0).getWriteLatency().getAverage();
+			}
 		}
 		for(final Runnable r : runnableList ) {
 			result = result.add(getRunnableMemoryAccessTime(r, freq, readLatency, writeLatency));
@@ -435,7 +438,6 @@
 		readAccessParameter = (Math.ceil(sizeofReadLabels / 64.0) * (readLatency / frequency));
 		final Time readAccess = parameter.multiply(readAccessParameter);
 		result = result.add(readAccess); // LabelAccess(Read) added
-		
 		/* Write (LabelAccess): */
 		double writeAccessParameter = 0;
 		double sizeofWriteLabels = 0;
diff --git a/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/ui/APP4RTA.java b/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/ui/APP4RTA.java
index b4881f8..f71f927 100644
--- a/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/ui/APP4RTA.java
+++ b/eclipse-tools/responseTime-analyzer/plugins/org.eclipse.app4mc.gsoc_rta/src/org/eclipse/app4mc/gsoc_rta/ui/APP4RTA.java
@@ -53,6 +53,7 @@
 import org.eclipse.emf.common.util.EList;
 import javax.swing.SwingConstants;
 import javax.swing.filechooser.FileNameExtensionFilter;
+import javax.swing.JSeparator;
 
 /**
  * Date: August 21-2019 
@@ -189,9 +190,24 @@
 						jTextFieldArray[i].setText("" + defaultIA[i]);
 					}
 					return ;
+				} else if (currentPUList.size() == 1) {
+					final int numOfTasks = cpurta.getModel().getSwModel().getTasks().size();
+					for (int i = 0; i < numOfTasks; i++) {
+						jTextFieldArray[i].setText("0");
+					}
+					return ;
+				}
+				String str = "";
+				for (int i = 0; i < currentPUList.size(); i++) {
+					if (i == currentPUList.size() - 1) {
+						str = str + i; 
+						break;
+					}
+					str = str + i + ", ";
 				}
 				JOptionPane.showMessageDialog(frame, "ERROR: The length of the default integer array does not match with\n"
-						+ "the number of tasks in the target model.");
+						+ "the number of tasks in the target model.\n\n" + "Please assign the number(s) manually.\n" 
+						+ "Available PU number(s): " + str);
 			}
 		});
 		
@@ -467,6 +483,11 @@
 		        	selectedModelLbl.setText(currentFile.getName());
 		        	currentModel = loadedModel;
 					currentPUList = CommonUtils.getPUs(currentModel);
+					if (currentPUList.get(0).getAccessElements().size() == 0) {
+						JOptionPane.showMessageDialog(frame, "The selected model's processing unit(s) does(do) not have 'read & write Latency' values.\n\n"
+								+ "Therefore, the default value of 30 will be assigned for them.\n"
+								+ "This will affect the response time results.");
+					}
 					cpurta.setModel(currentModel);
 					cpurta.setTRT(cpurta.getDefaultTRT(currentModel));
 					cpurta.setPUl(currentPUList);
@@ -577,7 +598,7 @@
 						ecComboBox.setSelectedItem(null);
 					} else {
 						JOptionPane.showMessageDialog(frame, "WARNING: The selected model has no Event-Chain.\n"
-								+ "End to End EventChain Latency Calculation is impossible with this model.");
+								+ "End-to-End Event-Chain Latency Calculation is impossible with this model.");
 						// TODO: Something needs to be done here to prevent E2ELatency calculation.
 					}
 					frame.revalidate();
@@ -766,6 +787,9 @@
 				} else if (currentECList == null) {
 					JOptionPane.showMessageDialog(frame, "ERROR: Event-Chain List is empty somehow.");
 					return ;
+				} else if (currentECList.size() == 0) {
+					JOptionPane.showMessageDialog(frame, "ERROR: There is no Event-Chain in this model.");
+					return ;
 				} else if (ecComboBox.getSelectedItem() == null) {
 					JOptionPane.showMessageDialog(frame, "ERROR: Select an Event-Chain.");
 					return ;
@@ -1025,5 +1049,9 @@
 		lblApprta.setFont(new Font("Snap ITC", Font.ITALIC, 20));
 		lblApprta.setBounds(1050, 1, 120, 34);
 		frame.getContentPane().add(lblApprta);
+		
+		JSeparator separator = new JSeparator();
+		separator.setBounds(10, 557, 1160, 2);
+		frame.getContentPane().add(separator);
 	}
 }
\ No newline at end of file