diff --git a/example-data/nfv.xml b/example-data/nfv.xml
index b397e0c93139212c3844c78618f2da06e4d0d2dc..4b5b9d4f216bdc851caaa60395a7352a34ac9a64 100644
--- a/example-data/nfv.xml
+++ b/example-data/nfv.xml
@@ -41,9 +41,16 @@
     </virtual-storage-descriptor>
     <sw-image-desc>
       <id>asa-image</id>
+      <name>ASA image</name>
+      <version>1.1</version>
+      <checksum>
+	<algorithm>sha-224</algorithm>
+	<hash>deadbeef</hash>
+      </checksum>
       <container-format>bare</container-format>
       <disk-format>qcow2</disk-format>
       <min-ram>2.0</min-ram>
+      <size>1</size>
       <image>http://www.cisco.com/asa.qcow2</image>
     </sw-image-desc>
     <ext-cpd>
@@ -136,9 +143,16 @@
     </virtual-storage-descriptor>
     <sw-image-desc>
       <id>csr-image</id>
+      <name>CSR image</name>
+      <version>1.1</version>
+      <checksum>
+	<algorithm>sha-224</algorithm>
+	<hash>deadbeef</hash>
+      </checksum>
       <container-format>bare</container-format>
       <disk-format>qcow2</disk-format>
       <min-ram>2.0</min-ram>
+      <size>1</size>
       <image>http://www.cisco.com/csr.qcow2</image>
     </sw-image-desc>
     <ext-cpd>
diff --git a/src/yang/etsi-nfv-vnf.yang b/src/yang/etsi-nfv-vnf.yang
index 2e2a0ba8ec6faba020db739d591bf434d58c9eb5..668bb722c67aad9d2f7d0b79eef5759827e72ce5 100755
--- a/src/yang/etsi-nfv-vnf.yang
+++ b/src/yang/etsi-nfv-vnf.yang
@@ -804,6 +804,7 @@ submodule etsi-nfv-vnf {
              information element";
         }
         leaf name {
+          mandatory true;
           type string;
           description
             "The name of this software image.";
@@ -811,7 +812,9 @@ submodule etsi-nfv-vnf {
             "GS NFV IFA011: Section 7.1.6.5 SwImageDesc
              information element.";
         }
+
         leaf version {
+	  mandatory true;
           type string;
           description
             "The version of this software image.";
@@ -819,8 +822,11 @@ submodule etsi-nfv-vnf {
             "GS NFV IFA011: Section 7.1.6.5 SwImageDesc
              information element.";
         }
+
         container checksum {
+
           leaf algorithm {
+	    mandatory true;
             type identityref {
 	      base checksum-algorithm;
 	    }
@@ -831,7 +837,9 @@ submodule etsi-nfv-vnf {
               "GS NFV IFA011: Section 7.1.6.10 ChecksumData
                information element.";
 	  }
+
 	  leaf hash {
+	    mandatory true;
 	    type string;
 	    description
 	      "Contains the result of applying the algorithm
@@ -847,6 +855,7 @@ submodule etsi-nfv-vnf {
             "GS NFV IFA011: Section 7.1.6.5 SwImageDesc
              information element.";
         }
+
         leaf container-format {
           default "bare";
           type enumeration {
@@ -887,6 +896,7 @@ submodule etsi-nfv-vnf {
             "GS NFV IFA011: Section 7.1.6.5 SwImageDesc
              information element.";
         }
+
         leaf disk-format {
           default "qcow2";
           type enumeration {
@@ -945,6 +955,7 @@ submodule etsi-nfv-vnf {
             "The disk format of a software image is the format of
              the underlying disk image.";
         }
+
         leaf min-disk {
           type uint64;
           units "GB";
@@ -959,6 +970,7 @@ submodule etsi-nfv-vnf {
             "GS NFV IFA011: Section 7.1.6.5, SwImageDesc
              information element.";
         }
+
         leaf min-ram {
           type decimal64 {
             fraction-digits 1;
@@ -976,7 +988,9 @@ submodule etsi-nfv-vnf {
             "GS NFV IFA011: Section 7.1.6.5, SwImageDesc
              information element.";
         }
+
         leaf size {
+	  mandatory true;
           type uint64;
           units "GB";
           description
@@ -985,6 +999,7 @@ submodule etsi-nfv-vnf {
             "GS NFV IFA011: Section 7.1.6.5, SwImageDesc
              information element.";
         }
+
         leaf image {
           default ".";
           type inet:uri;
@@ -996,6 +1011,7 @@ submodule etsi-nfv-vnf {
             "GS NFV IFA011: Section 7.1.6.5, SwImageDesc
              information element.";
         }
+
         leaf operating-system {
           type string;
           description
@@ -1006,6 +1022,7 @@ submodule etsi-nfv-vnf {
             "GS NFV IFA011: Section 7.1.6.5, SwImageDesc
              information element.";
         }
+
         leaf-list supported-virtualization-environment {
           type string;
           description