diff --git a/AlgebraicDataflowArchitectureModel/src/algorithm/DerivingStorageResources.java b/AlgebraicDataflowArchitectureModel/src/algorithm/DerivingStorageResources.java
index 70f2248..0ae7a19 100644
--- a/AlgebraicDataflowArchitectureModel/src/algorithm/DerivingStorageResources.java
+++ b/AlgebraicDataflowArchitectureModel/src/algorithm/DerivingStorageResources.java
@@ -1,5 +1,9 @@
 package algorithm;
 
-public class DerivingStorageResources {
+import models.dataFlowModel.DataFlowModel;
 
+public class DerivingStorageResources {
+	public void run(DataFlowModel model) {
+		
+	}
 }
diff --git a/AlgebraicDataflowArchitectureModel/src/algorithm/UpdateConflictCheck.java b/AlgebraicDataflowArchitectureModel/src/algorithm/UpdateConflictCheck.java
index 4e5db4f..080ec7b 100644
--- a/AlgebraicDataflowArchitectureModel/src/algorithm/UpdateConflictCheck.java
+++ b/AlgebraicDataflowArchitectureModel/src/algorithm/UpdateConflictCheck.java
@@ -4,6 +4,7 @@
 
 import models.*;
 import models.dataConstraintModel.ChannelGenerator;
+import models.dataConstraintModel.ChannelMember;
 import models.dataConstraintModel.IdentifierTemplate;
 import models.dataFlowModel.DataFlowModel;
 import models.dataFlowModel.DataflowChannelGenerator;
@@ -58,6 +59,7 @@
 
 	public boolean run(DataFlowModel model) {
 		init();
+		boolean check = true;
 		for (Node node : model.getResourceDependencyGraph().getNodes()) {
 			if (ids.containsKey(node)) {
 				strongconnect(node);
@@ -66,8 +68,14 @@
 		System.out.println(strong.size() + " " +model.getResourceDependencyGraph().getNodes().size());
 		for(ChannelGenerator cg:model.getChannelGenerators()) {
 			DataflowChannelGenerator data = (DataflowChannelGenerator)cg;
-			
+			for(ChannelMember channel:data.getChannelMembers()) {
+				for(ChannelMember another:data.getChannelMembers()) {
+					if(!channel.equals(another)) {
+						check = channel.getIdentifierTemplate() != another.getIdentifierTemplate();
+					}
+				}
+			}
 		}
-		return strong.size() == 0;
+		return strong.size() == 0 && check;
 	}
 }
diff --git a/AlgebraicDataflowArchitectureModel/src/tests/DerivingStorageResourcesTest.java b/AlgebraicDataflowArchitectureModel/src/tests/DerivingStorageResourcesTest.java
new file mode 100644
index 0000000..15e00e8
--- /dev/null
+++ b/AlgebraicDataflowArchitectureModel/src/tests/DerivingStorageResourcesTest.java
@@ -0,0 +1,101 @@
+package tests;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import algorithm.DerivingStorageResources;
+import models.Edge;
+import models.dataConstraintModel.ChannelMember;
+import models.dataConstraintModel.ChannelSelector;
+import models.dataConstraintModel.GroupSelector;
+import models.dataConstraintModel.IdentifierTemplate;
+import models.dataFlowModel.DataFlowModel;
+import models.dataFlowModel.DataflowChannelGenerator;
+import models.dataFlowModel.ResourceDependencyGraph;
+
+public class DerivingStorageResourcesTest {
+	@Test
+	public void test() {
+		// Construct a data-flow architecture model.
+		DataFlowModel model = new DataFlowModel();
+		IdentifierTemplate customer_off = new IdentifierTemplate("customers.{customer_id}.off", 1); // an identifier template to specify a customer's
+																		// office resource
+		IdentifierTemplate company_add = new IdentifierTemplate("companies.{company_id}.add", 1); // an identifier template to specify a companie's
+																		// address resource
+		IdentifierTemplate customer_add = new IdentifierTemplate("customers.{customer_id}.add", 1); // an identifier template to specify a customer's
+																		// address resource
+
+		// === gin_1 ===
+		//
+		// {x1}.customer_off(c, set(x)) = x
+		// {x1}.customer_off(c, e) = c
+		//
+		DataflowChannelGenerator gin_1 = new DataflowChannelGenerator("gin_1"); // set customer's office (an input channel)
+		GroupSelector x1 = new GroupSelector();
+		ChannelMember customer_off_1 = new ChannelMember(customer_off);
+		customer_off_1.addSelector(x1); // x1 is determined by the path parameter in customer's office template, and
+										// serves as a group selector in this channel
+		gin_1.addChannelMember(customer_off_1);
+		assertEquals(customer_off.getNumberOfParameters(), customer_off_1.getSelectors().size());
+
+		// === gin_2 ===
+		//
+		// {x2}.company_add(a, set(y)) = y
+		// {x2}.company_add(a, e) = a
+		//
+		DataflowChannelGenerator gin_2 = new DataflowChannelGenerator("gin_2"); // set companie's address (an input channel)
+		GroupSelector x2 = new GroupSelector();
+		ChannelMember company_add_1 = new ChannelMember(company_add);
+		company_add_1.addSelector(x2); // x2 is determined by the path parameter in companie's address template, and
+										// serves as a group selector in this channel
+		gin_2.addChannelMember(company_add_1);
+		assertEquals(company_add.getNumberOfParameters(), company_add_1.getSelectors().size());
+
+		// === g ===
+		//
+		// {x3}.customer_off( c, update(y, z)) = y
+		// {y}.company_add( a1, update(y, z)) = z
+		// {x3}.customer_add(a2, update(y, z)) = z
+		//
+		DataflowChannelGenerator g = new DataflowChannelGenerator("g"); // update customer's address
+		GroupSelector x3 = new GroupSelector();
+		ChannelSelector y = new ChannelSelector();
+		ChannelMember customer_off_2 = new ChannelMember(customer_off);
+		ChannelMember company_add_2 = new ChannelMember(company_add);
+		ChannelMember customer_add_2 = new ChannelMember(customer_add);
+		customer_off_2.addSelector(x3); // x3 is determined by the path parameter in customer's office template, and
+										// serves as a group selector in this channel
+		company_add_2.addSelector(y); // y is determined by the value of the customer's office resource, and serves as
+										// a channel selector in this channel
+		customer_add_2.addSelector(x3); // x3 determines the path parameter in customer's address template to update
+		g.addChannelMemberAsInput(customer_off_2);
+		g.addChannelMemberAsInput(customer_add_2);
+		g.addChannelMemberAsOutput(company_add_2);
+		assertEquals(customer_off.getNumberOfParameters(), customer_off_2.getSelectors().size());
+		assertEquals(customer_add.getNumberOfParameters(), customer_add_2.getSelectors().size());
+		assertEquals(company_add.getNumberOfParameters(), company_add_2.getSelectors().size());
+
+		// Construct a data-flow architecture model.
+		model.addIOChannelGenerator(gin_1);
+		model.addIOChannelGenerator(gin_2);
+		model.addChannelGenerator(g);
+
+		// Check the model.
+		assertEquals(3, model.getIdentifierTemplates().size());
+		assertEquals(2, model.getIOChannelGenerators().size());
+		assertEquals(1, model.getChannelGenerators().size());
+
+		// Extract the resource dependency graph.
+		ResourceDependencyGraph resourceDependencyGraph = model.getResourceDependencyGraph();
+
+		// Check the graph.
+		assertEquals(3, resourceDependencyGraph.getNodes().size());
+		assertEquals(2, resourceDependencyGraph.getEdges().size());
+		for (Edge e : resourceDependencyGraph.getEdges()) {
+			System.out.println(e.getSource() + "->" + e.getDestination());
+		}
+		DerivingStorageResources storage = new DerivingStorageResources();
+		storage.run(model);
+	}
+}