Index: lams_common/conf/hibernate/mappings/org/lamsfoundation/lams/lesson/LearnerProgress.hbm.xml
===================================================================
diff -u -r96b3b3ff3f62e1bca1d299f75f512995388e420b -rc2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3
--- lams_common/conf/hibernate/mappings/org/lamsfoundation/lams/lesson/LearnerProgress.hbm.xml	(.../LearnerProgress.hbm.xml)	(revision 96b3b3ff3f62e1bca1d299f75f512995388e420b)
+++ lams_common/conf/hibernate/mappings/org/lamsfoundation/lams/lesson/LearnerProgress.hbm.xml	(.../LearnerProgress.hbm.xml)	(revision c2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3)
@@ -45,15 +45,11 @@
 				class="org.lamsfoundation.lams.learningdesign.Activity" />
 		</set>
 
-		<!-- uni-directional one-to-many association to completed activities -->
-		<set name="completedActivities" lazy="false" batch-size="20"
-			cascade="none" table="lams_progress_completed">
-			<key>
-				<column name="learner_progress_id" />
-			</key>
-			<many-to-many column="activity_id"
-				class="org.lamsfoundation.lams.learningdesign.Activity" />
-		</set>
+		<map name="completedActivities" lazy="false" batch-size="20" cascade="none" table="lams_progress_completed">
+			<key column="learner_progress_id"/>
+			<index-many-to-many column="activity_id" class="org.lamsfoundation.lams.learningdesign.Activity"/>
+			<element column="completed_date_time" type="java.util.Date"/>
+		</map>
 
 		<!-- bi-directional many-to-one association to User -->
 		<many-to-one name="user" lazy="false"
Index: lams_common/db/sql/create_lams_11_tables.sql
===================================================================
diff -u -r8300f0d96f19f17ea059dc59663a61cace7d583a -rc2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3
--- lams_common/db/sql/create_lams_11_tables.sql	(.../create_lams_11_tables.sql)	(revision 8300f0d96f19f17ea059dc59663a61cace7d583a)
+++ lams_common/db/sql/create_lams_11_tables.sql	(.../create_lams_11_tables.sql)	(revision c2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3)
@@ -799,6 +799,7 @@
 CREATE TABLE lams_progress_completed (
        learner_progress_id BIGINT(20) NOT NULL
      , activity_id BIGINT(20) NOT NULL
+     , completed_date_time DATETIME NOT NULL
      , PRIMARY KEY (learner_progress_id, activity_id)
      , INDEX (learner_progress_id)
      , CONSTRAINT FK_lams_progress_completed_1 FOREIGN KEY (learner_progress_id)
Index: lams_common/src/java/org/lamsfoundation/lams/dbupdates/patch0015_updateFrom22.sql
===================================================================
diff -u -rb7dfd7282a5fa53e746a9c35077576ad73d553ec -rc2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3
--- lams_common/src/java/org/lamsfoundation/lams/dbupdates/patch0015_updateFrom22.sql	(.../patch0015_updateFrom22.sql)	(revision b7dfd7282a5fa53e746a9c35077576ad73d553ec)
+++ lams_common/src/java/org/lamsfoundation/lams/dbupdates/patch0015_updateFrom22.sql	(.../patch0015_updateFrom22.sql)	(revision c2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3)
@@ -24,6 +24,9 @@
 -- LDEV-2107 --------------
 INSERT into lams_workspace_folder_type VALUES (3, 'PUBLIC SEQUENCES');
 
+-- LDEV-2115 --------------
+ALTER TABLE lams_progress_completed ADD COLUMN completed_date_time DATETIME NOT NULL;
+
 ----------------------Put all sql statements above here-------------------------
 
 -- If there were no errors, commit and restore autocommit to on
Index: lams_common/src/java/org/lamsfoundation/lams/learningdesign/strategy/BranchingActivityStrategy.java
===================================================================
diff -u -r9e5bb3ac431f66103fabfa02a533ef4851a609b7 -rc2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3
--- lams_common/src/java/org/lamsfoundation/lams/learningdesign/strategy/BranchingActivityStrategy.java	(.../BranchingActivityStrategy.java)	(revision 9e5bb3ac431f66103fabfa02a533ef4851a609b7)
+++ lams_common/src/java/org/lamsfoundation/lams/learningdesign/strategy/BranchingActivityStrategy.java	(.../BranchingActivityStrategy.java)	(revision c2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3)
@@ -86,7 +86,7 @@
 	        for(Iterator i = complexActivity.getActivities().iterator();i.hasNext();)
 	        {
 	            Activity currentActivity = (Activity)i.next();
-	            boolean actComplete = learnerProgress.getCompletedActivities().contains(currentActivity);
+	            boolean actComplete = learnerProgress.getCompletedActivities().containsKey(currentActivity);
 	            if ( isPreview && ! actComplete) {
 	            	// found one not complete, so can try more branches
 	            	return false;
Index: lams_common/src/java/org/lamsfoundation/lams/learningdesign/strategy/ComplexActivityStrategy.java
===================================================================
diff -u -ra7351da17f548464a76295a73e9cc17450a6ff39 -rc2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3
--- lams_common/src/java/org/lamsfoundation/lams/learningdesign/strategy/ComplexActivityStrategy.java	(.../ComplexActivityStrategy.java)	(revision a7351da17f548464a76295a73e9cc17450a6ff39)
+++ lams_common/src/java/org/lamsfoundation/lams/learningdesign/strategy/ComplexActivityStrategy.java	(.../ComplexActivityStrategy.java)	(revision c2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3)
@@ -61,7 +61,7 @@
 	        for(Iterator i = complexActivity.getActivities().iterator();i.hasNext();)
 	        {
 	            Activity currentActivity = (Activity)i.next();
-	            if(learnerProgress.getCompletedActivities().contains(currentActivity))
+	            if(learnerProgress.getCompletedActivities().containsKey(currentActivity))
 	                numOfCompletedActivities++;
 	        }
         }
Index: lams_common/src/java/org/lamsfoundation/lams/lesson/LearnerProgress.java
===================================================================
diff -u -r96b3b3ff3f62e1bca1d299f75f512995388e420b -rc2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3
--- lams_common/src/java/org/lamsfoundation/lams/lesson/LearnerProgress.java	(.../LearnerProgress.java)	(revision 96b3b3ff3f62e1bca1d299f75f512995388e420b)
+++ lams_common/src/java/org/lamsfoundation/lams/lesson/LearnerProgress.java	(.../LearnerProgress.java)	(revision c2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3)
@@ -36,6 +36,8 @@
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
+import java.util.Map;
+import java.util.TreeMap;
 import java.util.TreeSet;
 
 import org.apache.commons.lang.builder.EqualsBuilder;
@@ -102,7 +104,7 @@
      *  Set of completed activities that includes all completed activities
      *  before current activity.
      */
-    private Set completedActivities;
+    private Map completedActivities;
     
     /**
      * The activity that user just completed. The purpose of this
@@ -167,11 +169,11 @@
      */
     public LearnerProgress(User user,Lesson lesson)
     {
-        this(null,user,lesson,new TreeSet( new ActivityOrderComparator()),new TreeSet( new ActivityOrderComparator()));
+        this(null,user,lesson,new TreeSet( new ActivityOrderComparator()),new TreeMap( new ActivityOrderComparator()));
     }
     
     /** full constructor */
-    public LearnerProgress(Long learnerProgressId, User user, Lesson lesson, Set attemptedActivities, Set completedActivities)
+    public LearnerProgress(Long learnerProgressId, User user, Lesson lesson, Set attemptedActivities, Map completedActivities)
     {
         this.learnerProgressId = learnerProgressId;
         this.user = user;
@@ -242,13 +244,13 @@
      *           
      *
      */
-    public Set getCompletedActivities()
+    public Map getCompletedActivities()
     {
         
         return this.completedActivities;
     }
     
-    public void setCompletedActivities(java.util.Set completedActivities)
+    public void setCompletedActivities(java.util.Map completedActivities)
     {
         
         this.completedActivities = completedActivities;
@@ -303,10 +305,10 @@
      */
     public byte getProgressState(Activity activity)
     {
-        if (completedActivities.contains(activity))
+        if (completedActivities.containsKey(activity))
         {
             return ACTIVITY_COMPLETED;
-        }
+        } 
         else if (attemptedActivities.contains(activity))
         {
             return ACTIVITY_ATTEMPTED;
@@ -361,7 +363,7 @@
     		this.attemptedActivities.add(activity);
     	}
     	else if (state == LearnerProgress.ACTIVITY_COMPLETED) {
-    		this.completedActivities.add(activity);
+    		this.completedActivities.put(activity, new Date(System.currentTimeMillis()));
     	}
     }
 
@@ -488,7 +490,7 @@
                                       this.user.getUserId(),
                                       this.currentActivity != null ? this.currentActivity.getActivityId() : null,
                                       this.createIdArrayFrom(this.attemptedActivities),
-                                      this.createIdArrayFrom(this.completedActivities),
+                                      this.createIdArrayFrom(this.completedActivities.keySet()),
                                       isComplete());
     }
     
Index: lams_common/src/java/org/lamsfoundation/lams/lesson/service/LessonService.java
===================================================================
diff -u -re5c9d6208cedb95477b449363a244ded3efb753c -rc2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3
--- lams_common/src/java/org/lamsfoundation/lams/lesson/service/LessonService.java	(.../LessonService.java)	(revision e5c9d6208cedb95477b449363a244ded3efb753c)
+++ lams_common/src/java/org/lamsfoundation/lams/lesson/service/LessonService.java	(.../LessonService.java)	(revision c2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3)
@@ -632,7 +632,7 @@
 	    LessonService.log.debug("Removed activity from attempted activities");
 	}
 
-	removed = progress.getCompletedActivities().remove(activity);
+	removed = (progress.getCompletedActivities().remove(activity) != null);
 	if (removed) {
 	    recordUpdated = true;
 	    LessonService.log.debug("Removed activity from completed activities");
Index: lams_learning/src/java/org/lamsfoundation/lams/learning/export/service/PortfolioBuilder.java
===================================================================
diff -u -r0008a92961ecc6d41f1722f1b46eddf8f3a3b65d -rc2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3
--- lams_learning/src/java/org/lamsfoundation/lams/learning/export/service/PortfolioBuilder.java	(.../PortfolioBuilder.java)	(revision 0008a92961ecc6d41f1722f1b46eddf8f3a3b65d)
+++ lams_learning/src/java/org/lamsfoundation/lams/learning/export/service/PortfolioBuilder.java	(.../PortfolioBuilder.java)	(revision c2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3)
@@ -183,7 +183,7 @@
 
 	// if learner only include the attempted and completed activities
 	if (accessMode == ToolAccessMode.LEARNER
-		&& !(progress.getCompletedActivities().contains(activity) || progress.getAttemptedActivities()
+		&& !(progress.getCompletedActivities().containsKey(activity) || progress.getAttemptedActivities()
 			.contains(activity))) {
 	    return;
 	}
Index: lams_learning/src/java/org/lamsfoundation/lams/learning/progress/ProgressEngine.java
===================================================================
diff -u -re4c92abe243b6367ad45115df3e1f5ecec5e5de7 -rc2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3
--- lams_learning/src/java/org/lamsfoundation/lams/learning/progress/ProgressEngine.java	(.../ProgressEngine.java)	(revision e4c92abe243b6367ad45115df3e1f5ecec5e5de7)
+++ lams_learning/src/java/org/lamsfoundation/lams/learning/progress/ProgressEngine.java	(.../ProgressEngine.java)	(revision c2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3)
@@ -142,7 +142,7 @@
                                         +"learning design ["+ld.getTitle()+"], id["
                                         +ld.getLearningDesignId().longValue()
                                         +"]");
-        } else if ( progress.getCompletedActivities().contains(ld.getFirstActivity())  ) {
+        } else if ( progress.getCompletedActivities().containsKey(ld.getFirstActivity())  ) {
         	// special case - recalculating the appropriate current activity.
         	return doCalculateProgress(progress.getUser(), ld.getFirstActivity(), progress, new LinkedList<Long>());
         } else if ( canDoActivity(progress.getLesson(), ld.getFirstActivity()) ) {
@@ -241,7 +241,7 @@
     {
     	Activity nextActivity = transition.getToActivity();
     	
-    	if ( ! learnerProgress.getCompletedActivities().contains(nextActivity) ) {
+    	if ( ! learnerProgress.getCompletedActivities().containsKey(nextActivity) ) {
     		// normal case - the next activity is still yet to be done
     		
 	        learnerProgress.setPreviousActivity(completedActivity);
@@ -305,7 +305,7 @@
             
             
             ComplexActivity complexParent = (ComplexActivity) activityDAO.getActivityByActivityId(parent.getActivityId(),ComplexActivity.class);
-            if (! learnerProgress.getCompletedActivities().contains(complexParent) && !complexParent.areChildrenCompleted(learnerProgress))
+            if (! learnerProgress.getCompletedActivities().containsKey(complexParent) && !complexParent.areChildrenCompleted(learnerProgress))
             {
                 Activity nextActivity = complexParent.getNextActivityByParent(completedActivity);
                 
Index: lams_learning/src/java/org/lamsfoundation/lams/learning/service/LearnerService.java
===================================================================
diff -u -r8699a7e7934798d29851a8397f62838cecac282d -rc2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3
--- lams_learning/src/java/org/lamsfoundation/lams/learning/service/LearnerService.java	(.../LearnerService.java)	(revision 8699a7e7934798d29851a8397f62838cecac282d)
+++ lams_learning/src/java/org/lamsfoundation/lams/learning/service/LearnerService.java	(.../LearnerService.java)	(revision c2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3)
@@ -397,7 +397,7 @@
 	    Boolean clearCompletedFlag) {
 	LearnerProgress progress = learnerProgressDAO.getLearnerProgressByLearner(learnerId, lessonId);
 
-	if (!progress.getCompletedActivities().contains(activity)) {
+	if (!progress.getCompletedActivities().containsKey(activity)) {
 	    // if we skip a sequence in an optional sequence, or have been force completed for branching / optional
 	    // sequence
 	    // and we go back to the sequence later, then the LessonComplete flag must be reset so that it will step
Index: lams_learning/src/java/org/lamsfoundation/lams/learning/web/util/LearningWebUtil.java
===================================================================
diff -u -r0008a92961ecc6d41f1722f1b46eddf8f3a3b65d -rc2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3
--- lams_learning/src/java/org/lamsfoundation/lams/learning/web/util/LearningWebUtil.java	(.../LearningWebUtil.java)	(revision 0008a92961ecc6d41f1722f1b46eddf8f3a3b65d)
+++ lams_learning/src/java/org/lamsfoundation/lams/learning/web/util/LearningWebUtil.java	(.../LearningWebUtil.java)	(revision c2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3)
@@ -218,7 +218,7 @@
     	
 		if ( currentActivity == null ) {
 			progress = learnerService.joinLesson(learnerId, lesson.getLessonId());
-		} else if ( progress.getCompletedActivities().contains(currentActivity) ) {
+		} else if ( progress.getCompletedActivities().containsKey(currentActivity) ) {
 			return actionMappings.getCloseForward(currentActivity, lesson.getLessonId());
 		} else {
 			// Set activity as complete
@@ -322,7 +322,7 @@
 			
 			progressSummary.append("&completed=");
 			first = true;
-			for ( Object obj : learnerProgress.getCompletedActivities() ) {
+			for ( Object obj : learnerProgress.getCompletedActivities().keySet() ) {
 				Activity activity = (Activity ) obj;
 				if ( ! first ) {
 					progressSummary.append("_");
Index: lams_monitoring/src/java/org/lamsfoundation/lams/monitoring/service/MonitoringService.java
===================================================================
diff -u -r12450cbea53946ad074ec52d10f5e94ae207e1f9 -rc2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3
--- lams_monitoring/src/java/org/lamsfoundation/lams/monitoring/service/MonitoringService.java	(.../MonitoringService.java)	(revision 12450cbea53946ad074ec52d10f5e94ae207e1f9)
+++ lams_monitoring/src/java/org/lamsfoundation/lams/monitoring/service/MonitoringService.java	(.../MonitoringService.java)	(revision c2d2a9b8036e4bb9f3ff18ce70610c59fc6602d3)
@@ -1211,7 +1211,7 @@
 	    }
 
 	    // check if activity is already complete
-	    if (learnerProgress != null && learnerProgress.getCompletedActivities().contains(stopActivity)) {
+	    if (learnerProgress != null && learnerProgress.getCompletedActivities().containsKey(stopActivity)) {
 		return messageService.getMessage(MonitoringService.FORCE_COMPLETE_STOP_MESSAGE_ACTIVITY_DONE,
 			new Object[] { stopActivity.getTitle() });
 	    }
@@ -1352,7 +1352,7 @@
 	// be set.
 	if (stopReason == null) {
 	    LearnerProgress learnerProgress = learnerService.getProgress(learner.getUserId(), lessonId);
-	    if (learnerProgress.getCompletedActivities().contains(stopActivity)) {
+	    if (learnerProgress.getCompletedActivities().containsKey(stopActivity)) {
 		// we have reached the stop activity. It may have been the
 		// activity we just processed
 		// or it may have been a parent activity (e.g. an optional