diff --git a/test/testfiles/valid2007B4withIEDModifications.scd b/test/testfiles/valid2007B4withIEDModifications.scd
index 41574b493..72443afde 100644
--- a/test/testfiles/valid2007B4withIEDModifications.scd
+++ b/test/testfiles/valid2007B4withIEDModifications.scd
@@ -145,6 +145,8 @@
 					</LN>
 					<LN lnClass="CSWI" inst="1" lnType="Dummy.CSWIwithoutCtlModel">
 						<DOI name="Pos">
+							<SDI name="anotherPosDo">
+							</SDI>
 							<DAI name="ctlModel">
 								<Val>sbo-with-enhanced-security</Val>
 							</DAI>
@@ -163,7 +165,7 @@
 								<DAI name="numPls">
     								<Val>1</Val>
 								</DAI>
-                            </SDI>
+              </SDI>
 							<DAI name="ctlModel">
 								<Val>sbo-with-enhanced-security</Val>
 							</DAI>
@@ -330,6 +332,7 @@
 						</Inputs>
 					</LN>
 					<LN lnClass="tHarde" lnType="lnTypeWithoutDOs" />
+					<LN lnClass="CSWI" lnType="nonExistingLnType" />
 				</LDevice>
 			</Server>
 		</AccessPoint>
@@ -479,6 +482,8 @@
             <DA fc="CF" name="sVC" bType="Struct" type="ScaledValueConfig"/>
         </DOType>
 		<DOType cdc="ENC" id="Dummy.LLN0.Mod">
+			<SDO fc="ST" name="sdoName2" type="nonExistingDoType"/>
+			<SDO fc="ST" name="sdoName3" type="doTypeNotHavingAnyDaElements"/>
 			<DA fc="ST" name="stVal" bType="Enum" type="Dummy_Beh" />
 			<DA fc="ST" name="q" bType="Quality" />
 			<DA fc="ST" name="t" bType="Timestamp" />
@@ -531,12 +536,12 @@
 			<DA fc="ST" name="q" bType="Quality" />
 			<DA fc="ST" name="t" bType="Timestamp" />
 		</DOType>
-		<DOType cdc="LPL" id="Dummy.LLN0.NamPlt">
-			<DA fc="DC" name="vendor" bType="VisString255" />
-			<DA fc="DC" name="swRev" bType="VisString255" />
-			<DA fc="DC" name="d" bType="VisString255" />
-			<DA fc="DC" name="configRev" bType="VisString255" />
-			<DA fc="EX" name="ldNs" bType="VisString255" />
+		<DOType cdc="ENS" id="Dummy.LLN0.Health">
+			<DA fc="ST" name="stVal" bType="Enum" type="Dummy_Health" />
+			<DA fc="ST" name="q" bType="Quality" />
+			<DA fc="ST" name="t" bType="Timestamp" />
+		</DOType>
+		<DOType cdc="LPLSDF" id="doTypeNotHavingAnyDaElements">
 		</DOType>
 		<DOType cdc="DPL" id="Dummy.LPHD1.PhyNam">
 			<DA fc="DC" name="vendor" bType="VisString255" />
@@ -579,6 +584,8 @@
 			<DA fc="DC" name="d" bType="VisString255" />
 		</DOType>
 		<DOType cdc="DPC" id="Dummy.CSWI.Pos2">
+			<SDO fc="ST" name="anotherPosDo" type="Quality"/>
+			<SDO fc="ST" name="someQualityThing" type="Quality"/>
 			<DA fc="ST" name="stVal" bType="Dbpos" />
 			<DA fc="ST" name="q" bType="Quality" />
 			<DA fc="ST" name="t" bType="Timestamp" />
diff --git a/test/unit/editors/ied/do-container.test.ts b/test/unit/editors/ied/do-container.test.ts
index b4c3b4980..5f7974724 100644
--- a/test/unit/editors/ied/do-container.test.ts
+++ b/test/unit/editors/ied/do-container.test.ts
@@ -95,6 +95,16 @@ describe('do-container', () => {
       expect(nestedDOs!.length).to.eql(1);
       expect(nestedDOs![0].getAttribute('name')).to.eql('anotherSdo');
     });
+
+    it('which return an empty array if the DoType cannot be found', async () => {
+      element = await fixture(html`<do-container
+        .element=${validSCL.querySelector(
+          'DataTypeTemplates > DOType[id="Dummy.LLN0.Mod"] > SDO[name="sdoName2"]')}
+      ></do-container>`);
+  
+      const nestedDOs = element['getDOElements']();
+      expect(nestedDOs).to.be.empty;
+    });
     
     it('which return an empty array if a DO doesn\t have child (S)DO\'s.', async () => {
       element = await fixture(html`<do-container
@@ -106,4 +116,126 @@ describe('do-container', () => {
       expect(nestedDOs).to.be.empty;
     });
   });
+
+  describe('has a getDAElements function ', () => {
+    it('which return the DA containers underneath a given DO.', async () => {
+      element = await fixture(html`<do-container
+        .element=${validSCL.querySelector(
+          'DataTypeTemplates > LNodeType[id="Dummy.LLN0"] > DO[name="ExtendedMod"]')}
+      ></do-container>`);
+  
+      const nestedDOs = element['getDAElements']();
+      expect(nestedDOs).to.not.be.empty;
+      expect(nestedDOs!.length).to.eql(14);
+      expect(nestedDOs![2].getAttribute('name')).to.eql('t');
+    });
+
+    it('which return an empty array if the DoType cannot be found', async () => {
+      element = await fixture(html`<do-container
+        .element=${validSCL.querySelector(
+          'DataTypeTemplates > DOType[id="Dummy.LLN0.Mod"] > SDO[name="sdoName2"]')}
+      ></do-container>`);
+  
+      const nestedDOs = element['getDAElements']();
+      expect(nestedDOs).to.be.empty;
+    });
+    
+    it('which return an empty array if a DO doesn\t have child DA\'s.', async () => {
+      element = await fixture(html`<do-container
+        .element=${validSCL.querySelector(
+          'DataTypeTemplates > DOType[id="Dummy.LLN0.Mod"] > SDO[name="sdoName3"]')}
+      ></do-container>`);
+  
+      const nestedDOs = element['getDOElements']();
+      expect(nestedDOs).to.be.empty;
+    });
+  });
+
+  describe('has a getInstanceDOElement function ', () => {
+    it('which return a DOI when a DO has a valid instance element.', async () => {
+      element = await fixture(html`<do-container
+        .element=${validSCL.querySelector(
+          'DataTypeTemplates > LNodeType[id="Dummy.CSWIwithoutCtlModel"] > DO[name="Pos"]')}
+        .instanceElement=${validSCL.querySelector(
+          'IED[name="IED1"] > AccessPoint[name="P1"] > Server > LDevice[inst="CircuitBreaker_CB1"] > LN[lnClass="CSWI"] > DOI[name="Pos"]')}
+      ></do-container>`);
+
+      const sdo = validSCL.querySelector('DataTypeTemplates > DOType[id="Dummy.CSWI.Pos2"] > SDO[name="anotherPosDo"]')
+  
+      const doi = element['getInstanceDOElement'](sdo!);
+      expect(doi).to.not.be.null;
+      expect(doi?.tagName).to.eql('SDI');
+      expect(doi?.getAttribute('name')).to.eql('anotherPosDo');
+    });
+
+    it('which returns null if there\'s no SDI available within a DOI.', async () => {
+      element = await fixture(html`<do-container
+        .element=${validSCL.querySelector(
+          'DataTypeTemplates > LNodeType[id="Dummy.CSWIwithoutCtlModel"] > DO[name="Pos"]')}
+        .instanceElement=${validSCL.querySelector(
+          'IED[name="IED1"] > AccessPoint[name="P1"] > Server > LDevice[inst="CircuitBreaker_CB1"] > LN[lnClass="CSWI"] > DOI[name="Pos"]')}
+      ></do-container>`);
+
+      const sdo = validSCL.querySelector('DataTypeTemplates > DOType[id="Dummy.CSWI.Pos2"] > SDO[name="someQualityThing"]')
+
+      const doi = element['getInstanceDOElement'](sdo!);
+      expect(doi).to.be.null;
+    });
+
+    it('which returns null if no root DOI is available.', async () => {
+      element = await fixture(html`<do-container
+        .element=${validSCL.querySelector(
+          'DataTypeTemplates > LNodeType[id="Dummy.CSWIwithoutCtlModel"] > DO[name="Pos"]')}
+      ></do-container>`);
+
+      const sdo = validSCL.querySelector('DataTypeTemplates > DOType[id="Dummy.CSWI.Pos2"] > SDO[name="someQualityThing"]')
+
+      const doi = element['getInstanceDOElement'](sdo!);
+      expect(doi).to.be.null;
+    });
+  });
+
+  describe('has a getInstanceDAElement function ', () => {
+    it('which return a DAI when a DA has a valid instance element.', async () => {
+      element = await fixture(html`<do-container
+        .element=${validSCL.querySelector(
+          'DataTypeTemplates > LNodeType[id="Dummy.CSWIwithoutCtlModel"] > DO[name="Pos"]')}
+        .instanceElement=${validSCL.querySelector(
+          'IED[name="IED1"] > AccessPoint[name="P1"] > Server > LDevice[inst="CircuitBreaker_CB1"] > LN[lnClass="CSWI"] > DOI[name="Pos"]')}
+      ></do-container>`);
+
+      const da = validSCL.querySelector('DataTypeTemplates > DOType[id="Dummy.CSWI.Pos2"] > DA[name="ctlModel"]')
+  
+      const dai = element['getInstanceDAElement'](da!);
+      expect(dai).to.not.be.null;
+      expect(dai?.tagName).to.eql('DAI');
+      expect(dai?.getAttribute('name')).to.eql('ctlModel');
+    });
+
+    it('which returns null if there\'s no DAI available within a DOI.', async () => {
+      element = await fixture(html`<do-container
+        .element=${validSCL.querySelector(
+          'DataTypeTemplates > LNodeType[id="Dummy.CSWIwithoutCtlModel"] > DO[name="Pos"]')}
+        .instanceElement=${validSCL.querySelector(
+          'IED[name="IED1"] > AccessPoint[name="P1"] > Server > LDevice[inst="CircuitBreaker_CB1"] > LN[lnClass="CSWI"] > DOI[name="Pos"]')}
+      ></do-container>`);
+
+      const da = validSCL.querySelector('DataTypeTemplates > DOType[id="Dummy.CSWI.Pos2"] > DA[name="d"]')
+
+      const dai = element['getInstanceDAElement'](da!);
+      expect(dai).to.be.null;
+    });
+
+    it('which returns null if no root DOI is available.', async () => {
+      element = await fixture(html`<do-container
+        .element=${validSCL.querySelector(
+          'DataTypeTemplates > LNodeType[id="Dummy.CSWIwithoutCtlModel"] > DO[name="Pos"]')}
+      ></do-container>`);
+
+      const da = validSCL.querySelector('DataTypeTemplates > DOType[id="Dummy.CSWI.Pos2"] > DA[name="d"]')
+
+      const dai = element['getInstanceDAElement'](da!);
+      expect(dai).to.be.null;
+    });
+  });
 });
diff --git a/test/unit/editors/ied/ln-container.test.ts b/test/unit/editors/ied/ln-container.test.ts
index a9917ea72..f3345174e 100644
--- a/test/unit/editors/ied/ln-container.test.ts
+++ b/test/unit/editors/ied/ln-container.test.ts
@@ -105,6 +105,15 @@ describe('ln-container', () => {
       const nestedDOs = element['getDOElements']();
       expect(nestedDOs).to.be.empty;
     });
+    
+    it('which return an empty array if the LNodeType of a LN doesn\'t exist.', async () => {
+      element = await fixture(html`<ln-container
+        .element=${validSCL.querySelector('LN[lnType="nonExistingLnType"]')}
+      ></ln-container>`);
+
+      const nestedDOs = element['getDOElements']();
+      expect(nestedDOs).to.be.empty;
+    });
   });
 
   describe('has a getInstanceElement function ', () => {