diff --git a/application/applicationextension.inc.php b/application/applicationextension.inc.php
index a007a3ab3..4576e4fa0 100644
--- a/application/applicationextension.inc.php
+++ b/application/applicationextension.inc.php
@@ -2246,3 +2246,25 @@ interface iModuleExtension
 	 */
 	public function __construct();
 }
+
+/**
+ * Interface to manipulate ormCaseLog objects after initialization/edition
+ *
+ * @api
+ * @private
+ * @since 3.1.0 N°6275
+ */
+interface iOrmCaseLogExtension
+{
+	public function __construct();
+
+	/**
+	 * Rebuild API to be able manipulate ormCaseLog after its initialization/modifications
+	 * Examples of use: fix ormcase log broken index/shrink huge histories/....
+	 * @param string $sLog: ormcaselog description
+	 * @param array|null $aIndex: ormcaselog index
+	 *
+	 * @return bool: indicate whether current ormCaseLog fields were touched
+	 */
+	public function Rebuild(&$sLog, &$aIndex) : bool;
+}
diff --git a/core/ormcaselog.class.inc.php b/core/ormcaselog.class.inc.php
index 52e1629d9..5646faf13 100644
--- a/core/ormcaselog.class.inc.php
+++ b/core/ormcaselog.class.inc.php
@@ -3,7 +3,7 @@
 //
 //   This file is part of iTop.
 //
-//   iTop is free software; you can redistribute it and/or modify	
+//   iTop is free software; you can redistribute it and/or modify
 //   it under the terms of the GNU Affero General Public License as published by
 //   the Free Software Foundation, either version 3 of the License, or
 //   (at your option) any later version.
@@ -25,10 +25,11 @@ use Combodo\iTop\Renderer\BlockRenderer;
 define('CASELOG_VISIBLE_ITEMS', 2);
 define('CASELOG_SEPARATOR', "\n".'========== %1$s : %2$s (%3$d) ============'."\n\n");
 
+require_once('ormcaselogservice.inc.php');
 
 /**
  * Class to store a "case log" in a structured way, keeping track of its successive entries
- *  
+ *
  * @copyright   Copyright (C) 2010-2023 Combodo SARL
  * @license     http://opensource.org/licenses/AGPL-3.0
  */
@@ -47,19 +48,22 @@ class ormCaseLog {
 	protected $m_sLog;
 	protected $m_aIndex;
 	protected $m_bModified;
-	
+	protected \ormCaseLogService $oOrmCaseLogService;
+
 	/**
 	 * Initializes the log with the first (initial) entry
 	 * @param $sLog string The text of the whole case log
 	 * @param $aIndex array The case log index
 	 */
-	public function __construct($sLog = '', $aIndex = array())
+	public function __construct($sLog = '', $aIndex = [], \ormCaseLogService $oOrmCaseLogService=null)
 	{
 		$this->m_sLog = $sLog;
 		$this->m_aIndex = $aIndex;
 		$this->m_bModified = false;
+		$this->oOrmCaseLogService = (is_null($oOrmCaseLogService)) ? new \ormCaseLogService() : $oOrmCaseLogService;
+		$this->RebuildIndex();
 	}
-	
+
 	public function GetText($bConvertToPlainText = false)
 	{
 		if ($bConvertToPlainText)
@@ -72,7 +76,7 @@ class ormCaseLog {
 			return $this->m_sLog;
 		}
 	}
-	
+
 	public static function FromJSON($oJson)
 	{
 		if (!isset($oJson->items))
@@ -88,8 +92,8 @@ class ormCaseLog {
 	}
 
 	/**
-	 * Return a value that will be further JSON encoded	
-	 */	
+	 * Return a value that will be further JSON encoded
+	 */
 	public function GetForJSON()
 	{
 		// Order by ascending date
@@ -199,9 +203,9 @@ class ormCaseLog {
 			$sSeparator = sprintf(CASELOG_SEPARATOR, $aData['date'], $aData['user_login'], $aData['user_id']);
 			$sPlainText .= $sSeparator.$aData['message'];
 		}
-		return $sPlainText;	
+		return $sPlainText;
 	}
-	
+
 	public function GetIndex()
 	{
 		return $this->m_aIndex;
@@ -227,7 +231,7 @@ class ormCaseLog {
     {
     	return count($this->m_aIndex);
     }
-	
+
 	public function ClearModifiedFlag()
 	{
 		$this->m_bModified = false;
@@ -235,7 +239,7 @@ class ormCaseLog {
 
 	/**
 	 * Produces an HTML representation, aimed at being used within an email
-	 */	 	
+	 */
 	public function GetAsEmailHtml()
 	{
 		$sStyleCaseLogHeader = '';
@@ -312,10 +316,10 @@ class ormCaseLog {
 		$sHtml .= '</td></tr></table>';
 		return $sHtml;
 	}
-	
+
 	/**
 	 * Produces an HTML representation, aimed at being used to produce a PDF with TCPDF (no table)
-	 */	 	
+	 */
 	public function GetAsSimpleHtml($aTransfoHandler = null)
 	{
 		$sStyleCaseLogEntry = '';
@@ -338,7 +342,7 @@ class ormCaseLog {
 					$sTextEntry = call_user_func($aTransfoHandler, $sTextEntry, true /* wiki "links" only */);
 				}
 				$sTextEntry = InlineImage::FixUrls($sTextEntry);
-			}			
+			}
 			$iPos += $aIndex[$index]['text_length'];
 
 			$sEntry = '<li>';
@@ -396,7 +400,7 @@ class ormCaseLog {
 
 	/**
 	 * Produces an HTML representation, aimed at being used within the iTop framework
-	 */	 	
+	 */
 	public function GetAsHTML(WebPage $oP = null, $bEditMode = false, $aTransfoHandler = null)
 	{
 		$bPrintableVersion = (utils::ReadParam('printable', '0') == '1');
@@ -519,7 +523,7 @@ class ormCaseLog {
 				}
 			}
 		}
-		
+
 		return  $sHtml;
 	}
 
@@ -534,7 +538,7 @@ class ormCaseLog {
 	 * @throws \ArchivedObjectException
 	 * @throws \CoreException
 	 * @throws \OQLException
-	 * 
+	 *
 	 * @since 3.0.0 New $iOnBehalfOfId parameter
 	 * @since 3.0.0 May throw \ArchivedObjectException exception
 	 */
@@ -585,6 +589,7 @@ class ormCaseLog {
 			'separator_length' => $iSepLength,
 			'format' => static::ENUM_FORMAT_HTML,
 		);
+		$this->RebuildIndex();
 		$this->m_bModified = true;
 	}
 
@@ -620,7 +625,7 @@ class ormCaseLog {
 			$iUserId = UserRights::GetUserId();
 			$sOnBehalfOf = UserRights::GetUserFriendlyName();
 		}
-		
+
 		if (isset($oJson->date))
 		{
 			$oDate = new DateTime($oJson->date);
@@ -653,14 +658,14 @@ class ormCaseLog {
 		$iTextlength = strlen($sText);
 		$this->m_sLog = $sSeparator.$sText.$this->m_sLog; // Latest entry printed first
 		$this->m_aIndex[] = array(
-			'user_name' => $sOnBehalfOf,	
-			'user_id' => $iUserId,	
-			'date' => $iDate,	
-			'text_length' => $iTextlength,	
+			'user_name' => $sOnBehalfOf,
+			'user_id' => $iUserId,
+			'date' => $iDate,
+			'text_length' => $iTextlength,
 			'separator_length' => $iSepLength,
 			'format' => $sFormat,
 		);
-
+		$this->RebuildIndex();
 		$this->m_bModified = true;
 	}
 
@@ -716,7 +721,7 @@ class ormCaseLog {
 		$iLast = end($aKeys); // Strict standards: the parameter passed to 'end' must be a variable since it is passed by reference
 		return $iLast;
 	}
-	
+
 	/**
 	 * Get the text string corresponding to the given entry in the log (zero based index, older entries first)
 	 * @param integer $iIndex
@@ -736,4 +741,16 @@ class ormCaseLog {
 		$sText = substr($this->m_sLog, $iPos, $this->m_aIndex[$index]['text_length']);
 		return InlineImage::FixUrls($sText);
 	}
+
+	/**
+	 * @since 3.1.0 N°6275
+	 */
+	public function RebuildIndex(): void
+	{
+		$oNewOrmCaseLog = $this->oOrmCaseLogService->Rebuild($this->m_sLog, $this->m_aIndex);
+		if (! is_null($oNewOrmCaseLog)) {
+			$this->m_aIndex = $oNewOrmCaseLog->m_aIndex;
+			$this->m_sLog = $oNewOrmCaseLog->m_sLog;
+		}
+	}
 }
diff --git a/core/ormcaselogservice.inc.php b/core/ormcaselogservice.inc.php
new file mode 100644
index 000000000..d1e933e3c
--- /dev/null
+++ b/core/ormcaselogservice.inc.php
@@ -0,0 +1,58 @@
+<?php
+/**
+ * @copyright   Copyright (C) 2010-2023 Combodo SARL
+ * @license     http://opensource.org/licenses/AGPL-3.0
+ */
+
+/**
+ * Service dedicated to ormCaseLog rebuild
+ *
+ * @since 3.1.0 N°6275
+ */
+class ormCaseLogService
+{
+	/**
+	 * Array of "providers" of welcome popup messages
+	 * @var iOrmCaseLogExtension[]
+	 */
+	protected $aOrmCaseLogExtension = null;
+
+	public function __construct()
+	{
+	}
+
+	protected function LoadCaseLogExtensions()
+	{
+		if ($this->aOrmCaseLogExtension !== null) return;
+
+		$aOrmCaseLogExtension = [];
+		$aProviderClasses = \utils::GetClassesForInterface(iOrmCaseLogExtension::class, '', array('[\\\\/]lib[\\\\/]', '[\\\\/]node_modules[\\\\/]', '[\\\\/]test[\\\\/]', '[\\\\/]tests[\\\\/]'));
+		foreach($aProviderClasses as $sProviderClass) {
+			$aOrmCaseLogExtension[] = new $sProviderClass();
+		}
+		$this->aOrmCaseLogExtension = $aOrmCaseLogExtension;
+	}
+
+	/**
+	 * @param string|null $sLog
+	 * @param array|null $aIndex
+	 *
+	 * @return \ormCaseLog|null: returns rebuilt ormCaseLog. null if not touched
+	 */
+	public function Rebuild($sLog, $aIndex) : ?\ormCaseLog
+	{
+		$this->LoadCaseLogExtensions();
+
+		$bTouched = false;
+		foreach ($this->aOrmCaseLogExtension as $oOrmCaseLogExtension){
+			/** var iOrmCaseLogExtension $oOrmCaseLogExtension */
+			$bTouched = $bTouched || $oOrmCaseLogExtension->Rebuild($sLog, $aIndex);
+		}
+
+		if ($bTouched){
+			return new \ormCaseLog($sLog, $aIndex);
+		}
+
+		return null;
+	}
+}
diff --git a/lib/composer/autoload_classmap.php b/lib/composer/autoload_classmap.php
index b85485524..b15367dce 100644
--- a/lib/composer/autoload_classmap.php
+++ b/lib/composer/autoload_classmap.php
@@ -2970,6 +2970,7 @@ return array(
     'lnkAuditCategoryToAuditDomain' => $baseDir . '/application/audit.domain.class.inc.php',
     'lnkTriggerAction' => $baseDir . '/core/trigger.class.inc.php',
     'ormCaseLog' => $baseDir . '/core/ormcaselog.class.inc.php',
+    'ormCaseLogService' => $baseDir . '/core/ormcaselogservice.inc.php',
     'ormCustomFieldsValue' => $baseDir . '/core/ormcustomfieldsvalue.class.inc.php',
     'ormDocument' => $baseDir . '/core/ormdocument.class.inc.php',
     'ormLinkSet' => $baseDir . '/core/ormlinkset.class.inc.php',
diff --git a/lib/composer/autoload_static.php b/lib/composer/autoload_static.php
index c10b2e716..15e466bb4 100644
--- a/lib/composer/autoload_static.php
+++ b/lib/composer/autoload_static.php
@@ -3335,6 +3335,7 @@ class ComposerStaticInit7f81b4a2a468a061c306af5e447a9a9f
         'lnkAuditCategoryToAuditDomain' => __DIR__ . '/../..' . '/application/audit.domain.class.inc.php',
         'lnkTriggerAction' => __DIR__ . '/../..' . '/core/trigger.class.inc.php',
         'ormCaseLog' => __DIR__ . '/../..' . '/core/ormcaselog.class.inc.php',
+        'ormCaseLogService' => __DIR__ . '/../..' . '/core/ormcaselogservice.inc.php',
         'ormCustomFieldsValue' => __DIR__ . '/../..' . '/core/ormcustomfieldsvalue.class.inc.php',
         'ormDocument' => __DIR__ . '/../..' . '/core/ormdocument.class.inc.php',
         'ormLinkSet' => __DIR__ . '/../..' . '/core/ormlinkset.class.inc.php',
diff --git a/tests/php-unit-tests/unitary-tests/core/ormCaseLogTest.php b/tests/php-unit-tests/unitary-tests/core/ormCaseLogTest.php
index 484be7951..18e3e3c6a 100644
--- a/tests/php-unit-tests/unitary-tests/core/ormCaseLogTest.php
+++ b/tests/php-unit-tests/unitary-tests/core/ormCaseLogTest.php
@@ -22,6 +22,32 @@ use ormCaseLog;
  */
 class ormCaseLogTest extends ItopDataTestCase
 {
+	const USE_TRANSACTION = false;
+	private $sLogin;
+	private $sPassword = "Iuytrez9876543ç_è-(";
+
+	public function setUp() :void{
+		parent::setUp(); // TODO: Change the autogenerated stub
+		//require_once APPROOT . "core/CaseLogService.php";
+
+		$oAdminProfile = \MetaModel::GetObjectFromOQL("SELECT URP_Profiles WHERE name = :name", array('name' => 'Administrator'), true);
+
+		if (is_object($oAdminProfile)) {
+			$this->sLogin = "admin-".date('dmYHis');
+
+			$this->CreateTestOrganization();
+
+			/** @var \Person $oPerson */
+			$oPerson = $this->createObject('Person', array(
+				'name' => $this->sLogin,
+				'first_name' => 'Test',
+				'org_id' => $this->getTestOrgId(),
+			));
+
+			$this->CreateUser($this->sLogin, $oAdminProfile->GetKey(), $this->sPassword, $oPerson->GetKey());
+		}
+	}
+
 	/**
 	 * @covers \ormCaseLog::GetEntryCount()
 	 * @throws \ArchivedObjectException
@@ -38,4 +64,141 @@ class ormCaseLogTest extends ItopDataTestCase
 		$oLog->AddLogEntry('First entry');
 		$this->assertEquals($oLog->GetEntryCount(), 1, 'Should be 1 entry, returned '.$oLog->GetEntryCount());
 	}
+
+	public function testConstructorWithoutRebuild(){
+		$oOrmCaseLogService = $this->createMock(\ormCaseLogService::class);
+		$sLog = "aaaaa";
+		$aInitialIndex = ['a' => 'b'];
+
+		$oOrmCaseLogService->expects($this->exactly(1))
+			->method('Rebuild')
+			->with($sLog, $aInitialIndex)
+			->willReturn(null);
+
+		$oLog = new ormCaseLog($sLog, $aInitialIndex, $oOrmCaseLogService);
+		$this->assertEquals($aInitialIndex, $oLog->GetIndex());
+		$this->assertEquals($sLog, $oLog->GetText());
+	}
+
+	public function testConstructorWithRebuild(){
+		$oOrmCaseLogService = $this->createMock(\ormCaseLogService::class);
+		$sLog = "aaaaa";
+		$sRebuiltLog = "bbbb";
+		$aInitialIndex = ['a' => 'b'];
+		$aRebuiltIndex = ['c' => 'd'];
+
+		$oOrmCaseLogService->expects($this->exactly(1))
+			->method('Rebuild')
+			->with($sLog, $aInitialIndex)
+			->willReturn(new ormCaseLog($sRebuiltLog, $aRebuiltIndex));
+
+		$oLog = new ormCaseLog($sLog, $aInitialIndex, $oOrmCaseLogService);
+		$this->assertEquals($aRebuiltIndex, $oLog->GetIndex());
+		$this->assertEquals($sRebuiltLog, $oLog->GetText());
+	}
+
+	public function AddLogEntryProvider(){
+		return [
+			'AddLogEntry' => [
+				'bTestAddLogEntry' => 'true'
+			],
+			'AddLogEntryFromJSON' => [
+				'bTestAddLogEntry' => 'false'
+			]
+		];
+	}
+
+
+	/**
+	 * @dataProvider AddLogEntryProvider
+	 */
+	public function testAddLogEntryNoRebuild($bTestAddLogEntry=true){
+		$_SESSION = array();
+		$this->assertTrue(\UserRights::Login($this->sLogin));
+
+		$sLog = "aaaaa";
+		$sDate = date(\AttributeDateTime::GetInternalFormat());
+		$iUserId = \UserRights::GetUserId();
+		$sOnBehalfOf = \UserRights::GetUserFriendlyName();
+		$sSeparator = sprintf(CASELOG_SEPARATOR, $sDate, $sOnBehalfOf, $iUserId);
+		$sExpectedLog = $sSeparator."<p>$sLog</p>";
+
+		$oOrmCaseLogService = $this->createMock(\ormCaseLogService::class);
+		$aExpectedIndex = [
+			[
+				'user_name' => $sOnBehalfOf,
+				'user_id' => $iUserId,
+				'date' => time(),
+				'text_length' => 12,
+				'separator_length' => strlen($sSeparator),
+				'format' => 'html',
+			]
+		];
+
+		$oOrmCaseLogService->expects($this->exactly(2))
+			->method('Rebuild')
+			->withConsecutive(['', []], [$sExpectedLog, $aExpectedIndex])
+			->willReturnOnConsecutiveCalls(null, null);
+
+		$oLog = new ormCaseLog('', [], $oOrmCaseLogService);
+		if ($bTestAddLogEntry){
+			$oLog->AddLogEntry($sLog);
+		} else {
+			$sJson = json_encode(
+				[
+					'user_login' => 'gabuzmeu',
+					'message' => $sLog,
+				]
+			);
+			$oJson = json_decode($sJson);
+			$oLog->AddLogEntryFromJSON($oJson, false);
+		}
+
+		$this->assertEquals($sExpectedLog, $oLog->GetText());
+		$this->assertEquals($aExpectedIndex, $oLog->GetIndex());
+	}
+
+	/**
+	 * @dataProvider AddLogEntryProvider
+	 */
+	public function testAddLogEntry($bTestAddLogEntry=true){
+		$_SESSION = array();
+		$this->assertTrue(\UserRights::Login($this->sLogin));
+
+		$sLog = "aaaaa";
+		$sDate = date(\AttributeDateTime::GetInternalFormat());
+		$iUserId = \UserRights::GetUserId();
+		$sOnBehalfOf = \UserRights::GetUserFriendlyName();
+		$sSeparator = sprintf(CASELOG_SEPARATOR, $sDate, $sOnBehalfOf, $iUserId);
+		$sExpectedLog = $sSeparator."<p>$sLog</p>";
+
+		$aRebuiltIndex = ['c' => 'd'];
+		$sRebuiltLog = "bbbb";
+
+		$oOrmCaseLogService = $this->createMock(\ormCaseLogService::class);
+
+		$aExpectedIndex = [
+			[
+				'user_name' => $sOnBehalfOf,
+				'user_id' => $iUserId,
+				'date' => time(),
+				'text_length' => 12,
+				'separator_length' => strlen($sSeparator),
+				'format' => 'html',
+			]
+		];
+		$oOrmCaseLogService->expects($this->exactly(2))
+			->method('Rebuild')
+			->withConsecutive(['', []], [$sExpectedLog, $aExpectedIndex])
+			->willReturnOnConsecutiveCalls(
+				null,
+				new ormCaseLog($sRebuiltLog, $aRebuiltIndex)
+			);
+
+		$oLog = new ormCaseLog('', [], $oOrmCaseLogService);
+		$oLog->AddLogEntry($sLog);
+
+		$this->assertEquals($sRebuiltLog, $oLog->GetText());
+		$this->assertEquals($aRebuiltIndex, $oLog->GetIndex());
+	}
 }