diff --git a/queen-v2/src/components/lightOrchestrator/LoopPanel/component.js b/queen-v2/src/components/lightOrchestrator/LoopPanel/component.js
index 50a5a559..fb91674a 100644
--- a/queen-v2/src/components/lightOrchestrator/LoopPanel/component.js
+++ b/queen-v2/src/components/lightOrchestrator/LoopPanel/component.js
@@ -1,14 +1,12 @@
-import { memo, useEffect, useState } from 'react';
+import { memo } from 'react';
 import { useStyles } from './component.style';
 import { Panel } from './panel';
 
-const LoopPanelNotMemo = ({ loopVariables = [], getData, pager, goToPage }) => {
+const LoopPanelNotMemo = ({ loopVariables = [], allData, pager, goToPage }) => {
   const noLoopVariables = loopVariables.length === 0 || loopVariables[0] === undefined;
 
   const classes = useStyles();
 
-  const [datas, setDatas] = useState(null);
-
   const {
     page: currentPage,
     subPage: currentSubPage,
@@ -16,17 +14,12 @@ const LoopPanelNotMemo = ({ loopVariables = [], getData, pager, goToPage }) => {
     lastReachedPage,
   } = pager;
 
-  useEffect(() => {
-    if (!noLoopVariables) setDatas(getData());
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [noLoopVariables, loopVariables]);
-
   if (noLoopVariables) return null;
 
   // use page to select loopVariables depth
   const depth = 0;
   const targetVariable = loopVariables[depth];
-  const targetData = datas?.COLLECTED[targetVariable];
+  const targetData = allData?.COLLECTED[targetVariable];
   const COLLECTED = targetData?.COLLECTED;
   if (COLLECTED && (COLLECTED.length === 0 || COLLECTED[0] === null)) return null;
 
diff --git a/queen-v2/src/components/lightOrchestrator/lightOrchestrator.js b/queen-v2/src/components/lightOrchestrator/lightOrchestrator.js
index c8c71b7d..3f6a469f 100644
--- a/queen-v2/src/components/lightOrchestrator/lightOrchestrator.js
+++ b/queen-v2/src/components/lightOrchestrator/lightOrchestrator.js
@@ -1,11 +1,12 @@
 import { useLunatic } from '@inseefr/lunatic';
 
-import { memo, useCallback, useEffect, useMemo, useRef, useState } from 'react';
+import { memo, useEffect, useMemo, useRef, useState } from 'react';
 import ButtonContinue from './buttons/continue/index';
 
 import D from 'i18n';
 import { componentHasResponse } from 'utils/components/deduceState';
 import { QUEEN_URL } from 'utils/constants';
+import { useConstCallback } from 'utils/hook/useConstCallback';
 import { LoopPanel } from './LoopPanel';
 import { ComponentDisplayer } from './componentDisplayer';
 import Header from './header';
@@ -36,6 +37,7 @@ function LightOrchestrator({
   missing = true,
   shortcut = true,
   autoSuggesterLoading,
+  allData,
   filterDescription,
   onChange = onLogChange,
   onDataChange = noDataChange,
@@ -47,7 +49,7 @@ function LightOrchestrator({
   const classes = useStyles();
   const lunaticStateRef = useRef();
 
-  const lightCustomHandleChange = useCallback(valueChange => {
+  const lightCustomHandleChange = useConstCallback(valueChange => {
     if (lunaticStateRef === undefined) return;
     const { getComponents, goNextPage } = lunaticStateRef.current;
     const currentComponent = getComponents()?.[0];
@@ -60,13 +62,13 @@ function LightOrchestrator({
     ) {
       goNextPage();
     }
-  }, []);
+  });
 
-  const missingStrategy = useCallback(() => {
+  const missingStrategy = useConstCallback(() => {
     if (lunaticStateRef === undefined) return;
     const { goNextPage } = lunaticStateRef.current;
     goNextPage();
-  }, []);
+  });
 
   // TODO restore when lunatic handle object in missingButtons properties
   // const dontKnowButton = <MissingButton shortcutLabel="F2" buttonLabel={D.doesntKnowButton} />;
@@ -89,6 +91,7 @@ function LightOrchestrator({
     missingShortcut,
     dontKnowButton,
     refusedButton,
+    trackChanges: true,
     workersBasePath: `${QUEEN_URL}/workers`,
   });
 
@@ -106,7 +109,8 @@ function LightOrchestrator({
     // getErrors,
     // getModalErrors,
     // getCurrentErrors,
-    getData,
+    // getData,
+    // getChangedData,
     loopVariables = [],
     Provider,
     pageTag,
@@ -118,30 +122,30 @@ function LightOrchestrator({
   useEffect(() => {
     const savingTask = async () => {
       if (lunaticStateRef.current === undefined) return;
-      const { getData: freshGetData, pageTag, pager } = lunaticStateRef.current;
+      const { getChangedData: freshGetChangedData, pageTag, pager } = lunaticStateRef.current;
       if (previousPageTag.current === undefined) {
         previousPageTag.current = pageTag;
         return;
       }
       if (pageTag !== previousPageTag.current) {
         previousPageTag.current = pageTag;
-        const allData = freshGetData();
-        onDataChange(allData.COLLECTED);
-        save(undefined, allData, pager.lastReachedPage);
+        const partialData = freshGetChangedData(true);
+        onDataChange(partialData);
+        save(undefined, partialData, pager.lastReachedPage);
       }
     };
     savingTask();
   }, [save, pager, onDataChange]);
 
-  const memoQuit = useCallback(() => {
-    const { getData: freshGetData, pager: freshPager } = lunaticStateRef.current;
-    quit(freshPager, freshGetData);
-  }, [quit]);
+  const memoQuit = useConstCallback(() => {
+    const { getChangedData: freshGetChangedData, pager: freshPager } = lunaticStateRef.current;
+    quit(freshPager, freshGetChangedData);
+  });
 
-  const memoDefinitiveQuit = useCallback(() => {
-    const { getData: freshGetData, pager: freshPager } = lunaticStateRef.current;
-    definitiveQuit(freshPager, freshGetData);
-  }, [definitiveQuit]);
+  const memoDefinitiveQuit = useConstCallback(() => {
+    const { getChangedData: freshGetChangedData, pager: freshPager } = lunaticStateRef.current;
+    definitiveQuit(freshPager, freshGetChangedData);
+  });
 
   const [components, setComponents] = useState([]);
 
@@ -156,23 +160,20 @@ function LightOrchestrator({
   // const modalErrors = getModalErrors();
   // const currentErrors = typeof getCurrentErrors === 'function' ? getCurrentErrors() : [];
 
-  const trueGoToPage = useCallback(
-    targetPage => {
-      if (typeof targetPage === 'string') {
-        goToPage({ page: targetPage });
-      } else {
-        const { page, iteration, subPage } = targetPage;
-        goToPage({ page: page, iteration: iteration, subPage: subPage });
-      }
-    },
-    [goToPage]
-  );
+  const trueGoToPage = useConstCallback(targetPage => {
+    if (typeof targetPage === 'string') {
+      goToPage({ page: targetPage });
+    } else {
+      const { page, iteration, subPage } = targetPage;
+      goToPage({ page: page, iteration: iteration, subPage: subPage });
+    }
+  });
 
-  const goToLastReachedPage = useCallback(() => {
+  const goToLastReachedPage = useConstCallback(() => {
     if (lunaticStateRef.current === undefined) return;
     const { pager } = lunaticStateRef.current;
     trueGoToPage(pager.lastReachedPage);
-  }, [trueGoToPage]);
+  });
 
   const firstComponent = useMemo(() => [...components]?.[0], [components]);
   const hasResponse = componentHasResponse(firstComponent);
@@ -228,7 +229,7 @@ function LightOrchestrator({
             </Provider>
             <LoopPanel
               loopVariables={loopVariables}
-              getData={getData}
+              allData={allData}
               pager={pager}
               goToPage={trueGoToPage}
             ></LoopPanel>
diff --git a/queen-v2/src/components/orchestratorManager/orchestratorManager.js b/queen-v2/src/components/orchestratorManager/orchestratorManager.js
index 541218c5..5fbaf99a 100644
--- a/queen-v2/src/components/orchestratorManager/orchestratorManager.js
+++ b/queen-v2/src/components/orchestratorManager/orchestratorManager.js
@@ -1,4 +1,4 @@
-import { useCallback, useContext, useEffect, useMemo, useState } from 'react';
+import { useContext, useEffect, useMemo, useState } from 'react';
 import { useHistory, useParams } from 'react-router-dom';
 import { ORCHESTRATOR_COLLECT, ORCHESTRATOR_READONLY, READ_ONLY } from 'utils/constants';
 import { EventsManager, INIT_ORCHESTRATOR_EVENT, INIT_SESSION_EVENT } from 'utils/events';
@@ -11,12 +11,14 @@ import Error from 'components/shared/Error';
 import NotFound from 'components/shared/not-found';
 import Preloader from 'components/shared/preloader';
 import { sendCloseEvent } from 'utils/communication';
+import { useConstCallback } from 'utils/hook/useConstCallback';
 import surveyUnitIdbService from 'utils/indexedbb/services/surveyUnit-idb-service';
-import { checkQuestionnaire } from 'utils/questionnaire';
+import { checkQuestionnaire, getFullData, removeNullCollectedData } from 'utils/questionnaire';
 
 export const OrchestratorManager = () => {
   const { standalone, apiUrl } = useContext(AppContext);
   const { readonly: readonlyParam, idQ, idSU } = useParams();
+  const [surveyUnitData, setSurveyUnitData] = useState(null);
   const history = useHistory();
 
   const readonly = readonlyParam === READ_ONLY;
@@ -34,7 +36,6 @@ export const OrchestratorManager = () => {
   const { surveyUnit, questionnaire, loadingMessage, errorMessage } = useAPIRemoteData(idSU, idQ);
 
   const stateData = surveyUnit?.stateData;
-  const initialData = surveyUnit?.data;
   const { oidcUser } = useAuth();
   const isAuthenticated = !!oidcUser?.profile;
 
@@ -46,7 +47,6 @@ export const OrchestratorManager = () => {
   const { putUeData /* postParadata */ } = useAPI();
   const [getState, changeState, onDataChange] = useQuestionnaireState(
     surveyUnit?.id,
-    initialData,
     stateData?.state
   );
 
@@ -66,6 +66,7 @@ export const OrchestratorManager = () => {
       const { valid, error: questionnaireError } = checkQuestionnaire(questionnaire);
       if (valid) {
         setSource(questionnaire);
+        setSurveyUnitData(surveyUnit.data);
         setInit(true);
         LOGGER.log(INIT_ORCHESTRATOR_EVENT);
       } else {
@@ -81,84 +82,76 @@ export const OrchestratorManager = () => {
   /** take a survey-unit as parameter, then save it in IDB, then save paradatas in IDB
    *  If in standalone mode : make API calls to persist data in DB
    */
-  const saveData = useCallback(
-    async unit => {
-      if (!readonly) {
-        const putSurveyUnit = async unit => {
-          const { id, ...other } = unit;
-          await putUeData(id, other);
-        };
-
-        await surveyUnitIdbService.addOrUpdateSU(unit);
-
-        /**
-         * Disable temporaly paradata
-         *
-         * const paradatas = LOGGER.getEventsToSend();
-         */
-        // TODO : make a true update of paradatas : currently adding additional completed arrays => SHOULD save one and only one array
-        // await paradataIdbService.update(paradatas);
-        if (standalone) {
-          // TODO managing errors
-          await putSurveyUnit(unit);
-          // await postParadata(paradatas);
-        }
+  const saveData = useConstCallback(async unit => {
+    if (!readonly) {
+      const putSurveyUnit = async unit => {
+        const { id, ...other } = unit;
+        await putUeData(id, other);
+      };
+
+      await surveyUnitIdbService.addOrUpdateSU(unit);
+
+      /**
+       * Disable temporaly paradata
+       *
+       * const paradatas = LOGGER.getEventsToSend();
+       */
+      // TODO : make a true update of paradatas : currently adding additional completed arrays => SHOULD save one and only one array
+      // await paradataIdbService.update(paradatas);
+      if (standalone) {
+        // TODO managing errors
+        await putSurveyUnit(unit);
+        // await postParadata(paradatas);
       }
-    },
-    [putUeData, readonly, standalone]
-  );
-
-  const saveQueen = useCallback(
-    async (newState, newData, lastReachedPage) => {
-      const currentState = getState();
-      saveData({
-        comment: {},
-        ...surveyUnit,
-        stateData: {
-          state: newState ?? currentState,
-          date: new Date().getTime(),
-          currentPage: lastReachedPage,
-        },
-        data: newData ?? surveyUnit.data,
-      });
-    },
-    [getState, saveData, surveyUnit]
-  );
-
-  const closeOrchestrator = useCallback(() => {
+    }
+  });
+
+  const savePartialQueen = useConstCallback(async (newState, newPartialData, lastReachedPage) => {
+    const currentState = getState();
+
+    const newData = getFullData(surveyUnitData, removeNullCollectedData(newPartialData));
+    setSurveyUnitData(newData);
+    saveData({
+      comment: {},
+      ...surveyUnit,
+      stateData: {
+        state: newState ?? currentState,
+        date: new Date().getTime(),
+        currentPage: lastReachedPage,
+      },
+      data: newData ?? surveyUnitData,
+    });
+  });
+
+  const closeOrchestrator = useConstCallback(() => {
     if (standalone) {
       history.push('/');
     } else {
       sendCloseEvent(surveyUnit.id);
     }
-  }, [history, standalone, surveyUnit?.id]);
-
-  const quit = useCallback(
-    async (pager, getData) => {
-      const { page, maxPage, lastReachedPage } = pager;
-      const isLastPage = page === maxPage;
-      const newData = getData();
-      if (isLastPage) {
-        // TODO : make algo to calculate COMPLETED event
-        changeState(COMPLETED);
-        changeState(VALIDATED);
-        await saveQueen(VALIDATED, newData, lastReachedPage);
-      } else await saveQueen(undefined, newData, lastReachedPage);
-      closeOrchestrator();
-    },
-    [changeState, closeOrchestrator, saveQueen]
-  );
-
-  const definitiveQuit = useCallback(
-    async (pager, getData) => {
-      const { lastReachedPage } = pager;
-      const newData = getData();
+  });
+
+  const quit = useConstCallback(async (pager, getChangedData) => {
+    const { page, maxPage, lastReachedPage } = pager;
+    const isLastPage = page === maxPage;
+    const newData = getChangedData(true);
+    if (isLastPage) {
+      // TODO : make algo to calculate COMPLETED event
+      changeState(COMPLETED);
       changeState(VALIDATED);
-      await saveQueen(VALIDATED, newData, lastReachedPage);
-      closeOrchestrator();
-    },
-    [changeState, closeOrchestrator, saveQueen]
-  );
+      await savePartialQueen(VALIDATED, newData, lastReachedPage);
+    } else await savePartialQueen(undefined, newData, lastReachedPage);
+    closeOrchestrator();
+  });
+
+  const definitiveQuit = useConstCallback(async (pager, getChangedData) => {
+    const { lastReachedPage } = pager;
+    const newData = getChangedData(true);
+    changeState(VALIDATED);
+    await savePartialQueen(VALIDATED, newData, lastReachedPage);
+    closeOrchestrator();
+  });
+
   return (
     <>
       {![READ_ONLY, undefined].includes(readonlyParam) && <NotFound />}
@@ -169,6 +162,7 @@ export const OrchestratorManager = () => {
           surveyUnit={surveyUnit}
           source={source}
           getReferentiel={getReferentiel}
+          allData={surveyUnitData}
           autoSuggesterLoading={true}
           standalone={standalone}
           readonly={readonly}
@@ -177,7 +171,7 @@ export const OrchestratorManager = () => {
           missing={true}
           shortcut={true}
           filterDescription={false}
-          save={saveQueen}
+          save={savePartialQueen}
           onDataChange={onDataChange}
           close={closeOrchestrator}
           quit={quit}
diff --git a/queen-v2/src/components/visualizer/visualizer.js b/queen-v2/src/components/visualizer/visualizer.js
index cb31f1b9..a440e18d 100644
--- a/queen-v2/src/components/visualizer/visualizer.js
+++ b/queen-v2/src/components/visualizer/visualizer.js
@@ -1,6 +1,11 @@
-import { useCallback, useContext, useEffect, useState } from 'react';
+import { useContext, useEffect, useState } from 'react';
 import { useGetReferentiel, useRemoteData, useVisuQuery } from 'utils/hook';
-import { checkQuestionnaire, downloadDataAsJson } from 'utils/questionnaire';
+import {
+  checkQuestionnaire,
+  downloadDataAsJson,
+  getFullData,
+  removeNullCollectedData,
+} from 'utils/questionnaire';
 
 import { AppContext } from 'components/app';
 import LightOrchestrator from 'components/lightOrchestrator';
@@ -8,11 +13,13 @@ import Error from 'components/shared/Error';
 import Preloader from 'components/shared/preloader';
 import { useHistory } from 'react-router';
 import { useQuestionnaireState } from 'utils/hook/questionnaire';
+import { useConstCallback } from 'utils/hook/useConstCallback';
 import surveyUnitIdbService from 'utils/indexedbb/services/surveyUnit-idb-service';
 import QuestionnaireForm from './questionnaireForm';
 
 const Visualizer = () => {
   const { apiUrl, standalone } = useContext(AppContext);
+  const [surveyUnitData, setSurveyUnitData] = useState(null);
 
   const [surveyUnit, setSurveyUnit] = useState(undefined);
   const [error, setError] = useState(null);
@@ -30,7 +37,6 @@ const Visualizer = () => {
 
   const [getState, , onDataChange] = useQuestionnaireState(
     surveyUnit?.id,
-    suData?.data,
     suData?.stateData?.state
   );
 
@@ -55,6 +61,7 @@ const Visualizer = () => {
       const { valid, error: questionnaireError } = checkQuestionnaire(questionnaire);
       if (valid) {
         setSource(questionnaire);
+        setSurveyUnitData(suData?.data || {});
       } else {
         setError(questionnaireError);
       }
@@ -65,49 +72,39 @@ const Visualizer = () => {
     if (errorMessage) setError(errorMessage);
   }, [errorMessage]);
 
-  // const save = useCallback(async (unit, newData) => {
-  //   console.log(unit, newData);
-  //   await surveyUnitIdbService.addOrUpdateSU({
-  //     ...unit,
-  //     data: newData,
-  //   });
-  // }, []);
-
-  const save = useCallback(
-    async (newState, newData, lastReachedPage) => {
-      const currentState = getState();
-      const unit = {
-        ...surveyUnit,
-        stateData: {
-          state: newState ?? currentState,
-          date: new Date().getTime(),
-          currentPage: lastReachedPage,
-        },
-        data: newData ?? surveyUnit?.data,
-      };
-      await surveyUnitIdbService.addOrUpdateSU(unit);
-    },
-    [getState, surveyUnit]
-  );
-  const closeAndDownloadData = useCallback(
-    async (pager, getData) => {
-      const { lastReachedPage } = pager;
-      const newData = getData();
-      const unit = {
-        ...surveyUnit,
-        stateData: {
-          state: getState(),
-          date: new Date().getTime(),
-          currentPage: lastReachedPage,
-        },
-        data: newData ?? surveyUnit?.data,
-      };
-
-      downloadDataAsJson(unit, 'data');
-      history.push('/');
-    },
-    [getState, history, surveyUnit]
-  );
+  const savePartial = useConstCallback(async (newState, newPartialData, lastReachedPage) => {
+    const currentState = getState();
+
+    const newData = getFullData(surveyUnitData, removeNullCollectedData(newPartialData));
+    setSurveyUnitData(newData);
+    const unit = {
+      ...surveyUnit,
+      stateData: {
+        state: newState ?? currentState,
+        date: new Date().getTime(),
+        currentPage: lastReachedPage,
+      },
+      data: newData ?? surveyUnit.data,
+    };
+    await surveyUnitIdbService.addOrUpdateSU(unit);
+  });
+
+  const closeAndDownloadData = useConstCallback(async (pager, getChangedData) => {
+    const { lastReachedPage } = pager;
+    const newData = getFullData(surveyUnitData, removeNullCollectedData(getChangedData(true)));
+    const unit = {
+      ...surveyUnit,
+      stateData: {
+        state: getState(),
+        date: new Date().getTime(),
+        currentPage: lastReachedPage,
+      },
+      data: newData ?? surveyUnit?.data,
+    };
+
+    downloadDataAsJson(unit, 'data');
+    history.push('/');
+  });
 
   return (
     <>
@@ -119,11 +116,12 @@ const Visualizer = () => {
           source={source}
           autoSuggesterLoading={true}
           getReferentiel={getReferentielForVizu}
+          allData={surveyUnitData}
           standalone={standalone}
           readonly={readonly}
           pagination={true}
           missing={true}
-          save={save}
+          save={savePartial}
           onDataChange={onDataChange}
           filterDescription={false}
           quit={closeAndDownloadData}
diff --git a/queen-v2/src/utils/hook/questionnaire.js b/queen-v2/src/utils/hook/questionnaire.js
index 980b20b9..266eeb24 100644
--- a/queen-v2/src/utils/hook/questionnaire.js
+++ b/queen-v2/src/utils/hook/questionnaire.js
@@ -1,52 +1,37 @@
-import { sendCompletedEvent, sendStartedEvent, sendValidatedEvent } from 'utils/communication';
 import { useCallback, useRef } from 'react';
+import { sendCompletedEvent, sendStartedEvent, sendValidatedEvent } from 'utils/communication';
+import { useConstCallback } from './useConstCallback';
 
 export const NOT_STARTED = null;
 export const INIT = 'INIT';
 export const COMPLETED = 'COMPLETED';
 export const VALIDATED = 'VALIDATED';
 
-export const useQuestionnaireState = (idSurveyUnit, initialData, initialState = NOT_STARTED) => {
-  console.log('useQuestionnaireState', { idSurveyUnit, initialData, initialState });
+export const useQuestionnaireState = (idSurveyUnit, initialState = NOT_STARTED) => {
   const stateRef = useRef(initialState);
   const getState = useCallback(() => stateRef.current, []);
 
-  const initialDataRef = useRef(initialData);
-
   // Send an event when questionnaire's state has changed (started, completed, validated)
-  const changeState = useCallback(
-    newState => {
-      console.log('change state to ', newState);
-      if (newState === INIT) sendStartedEvent(idSurveyUnit);
-      if (newState === COMPLETED) sendCompletedEvent(idSurveyUnit);
-      if (newState === VALIDATED) sendValidatedEvent(idSurveyUnit);
-      stateRef.current = newState;
-    },
-    [idSurveyUnit]
-  );
-  const onDataChange = useCallback(
-    newData => {
-      // initialisation des data de référence
-      if (initialDataRef.current === undefined) {
-        console.log('persisting initial data');
-        initialDataRef.current = JSON.stringify(newData);
-      }
+  const changeState = useConstCallback(newState => {
+    if (newState === INIT) sendStartedEvent(idSurveyUnit);
+    if (newState === COMPLETED) sendCompletedEvent(idSurveyUnit);
+    if (newState === VALIDATED) sendValidatedEvent(idSurveyUnit);
+    stateRef.current = newState;
+  });
+  const onDataChange = useConstCallback((newData = {}) => {
+    const { COLLECTED = {} } = newData;
+    const hasDataChanged = Object.keys(COLLECTED).length > 0;
 
-      if (stateRef.current === NOT_STARTED) {
-        changeState(INIT);
-      } else if (
-        stateRef.current === VALIDATED &&
-        initialDataRef.current !== JSON.stringify(newData)
-      ) {
-        // state VALIDATED et données entrantes !== données initiales
-        changeState(INIT);
-      } else {
-        // here we do nothing
-        console.log({ newData, state: stateRef.current });
-      }
-    },
-    [changeState]
-  );
+    if (stateRef.current === NOT_STARTED) {
+      changeState(INIT);
+    } else if (stateRef.current === VALIDATED && hasDataChanged) {
+      // state VALIDATED et données entrantes !== données initiales
+      changeState(INIT);
+    } else {
+      // here we do nothing
+      console.log({ newData, state: stateRef.current });
+    }
+  });
 
   // Analyse collected variables to update state (only to STARTED state)