diff --git a/manifest.toml b/manifest.toml
index 8938c5e..fb1199c 100644
--- a/manifest.toml
+++ b/manifest.toml
@@ -51,6 +51,51 @@ ram.runtime = "50M" # FIXME: replace with an **estimate** minimum ram requiremen
     sha256 = "8639d466b26f0fba7d2b610a96ffcf36a657b1e00bdc2e5a1ac5287521dcb4ed"
     autoupdate.strategy = "latest_github_release"
 
+    [resources.sources.main_18_0_1]
+    url = "https://github.com/dolibarr/dolibarr/archive/18.0.1.tar.gz"
+    sha256 = "37bd3c8533b821c241dbb34b0e88349c1d5b43f7ffa6027f0b7970748d1f727a"
+    prefetch = false
+
+    [resources.sources.main_17_0_1]
+    url = "https://github.com/dolibarr/dolibarr/archive/17.0.1.tar.gz"
+    sha256 = "2eddd545c07eae291ad46e48ab55d3adb988d99c29a8dfaa2e2fde0a890b0ddc"
+    prefetch = false
+
+    [resources.sources.main_16_0_5]
+    url = "https://github.com/dolibarr/dolibarr/archive/16.0.5.tar.gz"
+    sha256 = "c8298342558e62b955a6f4c01fedb6a187b2e0c0b2c1681a97158ca979f9304f"
+    prefetch = false
+
+    [resources.sources.main_15_0_3]
+    url = "https://github.com/dolibarr/dolibarr/archive/15.0.3.tar.gz"
+    sha256 = "b145a38f56c44b166721d64909fb12408c6d10d08fcf74d2c00418a60201cc9d"
+    prefetch = false
+
+    [resources.sources.main_14_0_5]
+    url = "https://github.com/Dolibarr/dolibarr/archive/14.0.5.tar.gz"
+    sha256 = "31f4c934e484a9582d8867e4170f1f1acd8c41628b059370a6a449eb6e94ae75"
+    prefetch = false
+
+    [resources.sources.main_13_0_5]
+    url = "https://github.com/Dolibarr/dolibarr/archive/13.0.5.tar.gz"
+    sha256 = "08ec08dc5093d614361f273237f5aaf8d70e63d764c2fa8d7f3f68a1485156d0"
+    prefetch = false
+
+    [resources.sources.main_12_0_5]
+    url = "https://github.com/Dolibarr/dolibarr/archive/12.0.5.tar.gz"
+    sha256 = "b60b124ebcd294375f6200cc0683449e475b5dec687f8317b820fc8ec1413d21"
+    prefetch = false
+
+    [resources.sources.main_11_0_5]
+    url = "https://github.com/Dolibarr/dolibarr/archive/11.0.5.tar.gz"
+    sha256 = "6f51435a4ffe576e836bf6449d900de9a56016f09591322cb2ba47a07c97679d"
+    prefetch = false
+
+    [resources.sources.main_10_0_7]
+    url = "https://github.com/Dolibarr/dolibarr/archive/10.0.7.tar.gz"
+    sha256 = "6efc230f400a7b7152a0e4b9ba02a780f38b869b4aebd2bc28883268270ef871"
+    prefetch = false
+
     [resources.system_user]
 
     [resources.install_dir]
diff --git a/scripts/install b/scripts/install
index 82a6659..4c2c303 100644
--- a/scripts/install
+++ b/scripts/install
@@ -7,12 +7,6 @@
 source _common.sh
 source /usr/share/yunohost/helpers
 
-#=================================================
-# INITIALIZE AND STORE SETTINGS
-#=================================================
-
-ynh_app_setting_set --app=$app --key=version --value=$(ynh_app_upstream_version)
-
 #=================================================
 # CREATE A MYSQL DATABASE
 #=================================================
diff --git a/scripts/upgrade b/scripts/upgrade
index f4e71ea..72047c3 100755
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -7,47 +7,21 @@
 source _common.sh
 source /usr/share/yunohost/helpers
 
-update_version=$(ynh_app_upstream_version)
-
 #=================================================
 # ENSURE DOWNWARD COMPATIBILITY
 #=================================================
 ynh_script_progression --message="Ensuring downward compatibility..." --weight=1
 
-# If db_name doesn't exist, create it
-if [ -z "$db_name" ]; then
-	db_name=$(ynh_sanitize_dbid --db_name=$app)
-#REMOVEME? 	ynh_app_setting_set --app=$app --key=db_name --value=$db_name
-fi
-
-# If install_dir doesn't exist, create it
-if [ -z "$install_dir" ]; then
-#REMOVEME? 	install_dir=/var/www/$app
-#REMOVEME? 	ynh_app_setting_set --app=$app --key=install_dir --value=$install_dir
-fi
-
 # If fpm_footprint doesn't exist, create it
-if [ -z "$fpm_footprint" ]; then
-	fpm_footprint=medium
-	ynh_app_setting_set --app=$app --key=fpm_footprint --value=$fpm_footprint
+if [ -z "${fpm_footprint:-}" ]; then
+    fpm_footprint=medium
+    ynh_app_setting_set --app=$app --key=fpm_footprint --value=$fpm_footprint
 fi
 
 # If fpm_usage doesn't exist, create it
-if [ -z "$fpm_usage" ]; then
-	fpm_usage=medium
-	ynh_app_setting_set --app=$app --key=fpm_usage --value=$fpm_usage
-fi
-
-# Cleaning legacy permissions
-#REMOVEME? if ynh_legacy_permissions_exists; then
-#REMOVEME? 	ynh_legacy_permissions_delete_all
-
-	ynh_app_setting_delete --app=$app --key=is_public
-fi
-
-# Create a permission if needed
-#REMOVEME? if ! ynh_permission_exists --permission "public_space"; then
-#REMOVEME? 	ynh_permission_create --permission "public_space" --url "/public/" --allowed "visitors"
+if [ -z "${fpm_usage:-}" ]; then
+    fpm_usage=medium
+    ynh_app_setting_set --app=$app --key=fpm_usage --value=$fpm_usage
 fi
 
 # Delete existing ini configuration file (backward compatibility)
@@ -55,210 +29,56 @@ if [ -f /etc/php/$YNH_PHP_VERSION/fpm/conf.d/20-$app.ini ]; then
     ynh_secure_remove --file=/etc/php/$YNH_PHP_VERSION/fpm/conf.d/20-$app.ini
 fi
 
-#=================================================
-# CREATE DEDICATED USER
-#=================================================
-#REMOVEME? ynh_script_progression --message="Making sure dedicated system user exists..." --weight=1
+if [ -n "${version:-}" ]; then
+    ynh_app_setting_delete --app=$app --key="version"
+fi
 
-# Create a dedicated user (if not existing)
-#REMOVEME? ynh_system_user_create --username=$app --home_dir="$install_dir"
+charset=$(mysql -ss -N -e "SELECT default_character_set_name FROM information_schema.SCHEMATA WHERE schema_name = '$db_name'")
+if [ "$charset" != "utf8" ]; then
+    ynh_print_info --message="Changing Database charset to utf8"
+    ynh_mysql_execute_as_root --sql="ALTER DATABASE $db_name charset=utf8"
+    ynh_local_curl  "/install/repair.php" "force_utf8_on_tables=confirmed" > "/var/log/$app/repair.html"
+    ynh_exec_fully_quiet sleep 5
+fi
 
-#=================================================
-# UPGRADE DEPENDENCIES
-#=================================================
-#REMOVEME? ynh_script_progression --message="Upgrading dependencies..." --weight=1
-
-#REMOVEME? ynh_install_app_dependencies $pkg_dependencies
-
-#=================================================
-# NGINX CONFIGURATION
-#=================================================
-ynh_script_progression --message="Upgrading NGINX web server configuration..." --weight=1
-
-ynh_backup_if_checksum_is_different --file="/etc/nginx/conf.d/$domain.d/$app.conf"
-
-# Delete current NGINX configuration to be able to check if .well-known is already served.
-ynh_remove_nginx_config
-ynh_app_setting_delete --app=$app --key="checksum__etc_nginx_conf.d_$domain.d_$app.conf"
-
-# Wait untils NGINX has fully reloaded
-#REMOVEME? ynh_systemd_action --service_name=nginx --action=reload --line_match="Reloaded" --log_path="systemd"
-
-# Create a dedicated nginx config
-ynh_add_nginx_config
-
-#=================================================
-# PHP-FPM CONFIGURATION
-#=================================================
-ynh_script_progression --message="Upgrading PHP-FPM configuration..." --weight=2
-
-# If php has changed, remove the old fpm config file
-# if [ "$phpversion" != $YNH_PHP_VERSION ]
-# then
-    # ynh_backup_if_checksum_is_different --file="/etc/php/$phpversion/fpm/pool.d/$app.conf"
-    # ynh_secure_remove --file="/etc/php/$phpversion/fpm/pool.d/$app.conf"
-    # if [ -f /etc/php/$phpversion/fpm/conf.d/20-$app.ini ]; then
-        # ynh_secure_remove --file="/etc/php/$phpversion/fpm/conf.d/20-$app.ini"
-    # fi
-    # ynh_systemd_action --service_name="php${phpversion}-fpm" --action=reload
-
-    # phpversion="$YNH_PHP_VERSION"
-# fi
-
-# Recreate a dedicated PHP-FPM config
-ynh_add_fpm_config --usage=$fpm_usage --footprint=$fpm_footprint
-#REMOVEME? phpversion=$(ynh_app_setting_get --app=$app --key=phpversion)
-
-#=================================================
-# SPECIFIC UPGRADE
 #=================================================
 # MAKE SEQUENTIAL UPGRADES FROM EACH MAJOR
 # VERSION TO THE NEXT ONE
 #=================================================
-if [ "$upgrade_type" == "UPGRADE_APP" ]
-then
-	ynh_script_progression --message="Upgrading source files..." --weight=60
+ynh_script_progression --message="Upgrading source files..." --weight=60
 
-	# Load the last available version
-    source upgrade.d/upgrade.last.sh
-    last_version=$next_version
+# Sort --version-sort cdécembrean handle underscore in versions numbers
+mapfile -t main_versions < <(
+    ynh_read_manifest --key="resources.sources | keys[]" | grep "main_" | sort --version-sort
+)
+current_version="$YNH_APP_CURRENT_VERSION"
+for version in "${main_versions[@]}"; do
+    new_version=$(echo "$version" | sed 's|main_||' | sed 's|_|.|g')
+    if dpkg --compare-versions "$current_version" ge "$new_version"; then
+        continue
+    fi
+    ynh_print_info --message="Upgrading app from $current_version to $new_version"
+    source_id="$version"
+    upgrade_dolibarr
+    current_version="$new_version"
+done
 
-	last_major_version=${last_version%%.*}
+# Final upgrade to the final version
+new_version=$(ynh_app_upstream_version)
+ynh_print_info --message="Upgrading app from $current_version to $new_version"
+upgrade_dolibarr
 
-	# While the current version is not the last version, do an upgrade
-    while [ "$last_version" != "$current_version" ]
-    do
-
-		# The major version is the first part of the version number
-        current_major_version=${current_version%%.*}
-
-        if [ ! -f upgrade.d/upgrade.$current_major_version.sh ]; then
-            source upgrade.d/upgrade.last.sh
-        else
-            source upgrade.d/upgrade.$current_major_version.sh
-        fi
-
-		# If the current version has the same major version than the next one,
-        # then it's the last upgrade to do
-        # We also cover the case where the last version is the first of the current major version series
-        # (e.g. 20.0.0 is the latest version)
-        if [[ ("$last_major_version" -eq "$current_major_version") || ( ("$last_major_version" -eq "$((current_major_version+1))") && ("$next_version" == "$last_version") ) ]]; then
-            current_major_version=last
-        fi
-
-		# Load the value for this version
-        source upgrade.d/upgrade.$current_major_version.sh
-
-		ynh_print_info --message="Upgrading app from $current_version to $next_version"
-
-		# Create an app.src for this version of Dolibarr
-        cat > ../conf/app.src << EOF
-SOURCE_URL=https://github.com/Dolibarr/dolibarr/archive/$next_version.tar.gz
-SOURCE_SUM=$dolibarr_source_sha256
-SOURCE_SUM_PRG=sha256sum
-SOURCE_FORMAT=tar.bz2
-SOURCE_IN_SUBDIR=true
-EOF
-
-
-		chown -R $app: "$install_dir"
-
-		# Remove the lock if it exists
-		lock=$install_dir/documents/install.lock
-		if [ -f $lock ]
-		then
-			ynh_secure_remove $lock
-		fi
-
-		mkdir -p /var/log/$app/
-
-		# Upgrade with CURL
-
-		# Set the app as temporarily public for cURL call
-		if ! ynh_permission_has_user --permission "main" --user="visitors"; then
-#REMOVEME? 			ynh_permission_update --permission="main" --add="visitors"
-		fi
-
-
-		charset=$(mysql -ss -N -e "SELECT default_character_set_name FROM information_schema.SCHEMATA WHERE schema_name = '$db_name'")
-		if [ "$charset" != "utf8" ]
-		then
-			ynh_print_info --message="Changing Database charset to utf8"
-
-			ynh_mysql_execute_as_root --database=$db_name --sql="ALTER DATABASE $db_name charset=utf8"
-
-			ynh_local_curl  "/install/repair.php" \
-					"force_utf8_on_tables=confirmed" > /var/log/$app/repair.html
-		fi
-
-		ynh_exec_fully_quiet sleep 5
-
-		# Download, check integrity, uncompress and patch the source from app.src
-		ynh_setup_source --dest_dir="$install_dir"
-
-		pushd $install_dir/htdocs/install/
-
-		if php$phpversion upgrade.php $current_version $next_version > /var/log/$app/upgrade.html;  then
-			ynh_print_info --message="Step 1 upgrading ended successfully"
-		else
-			ynh_die --message="Step 1 upgrading ended with error"
-		fi
-
-		ynh_exec_fully_quiet sleep 5
-
-		if php$phpversion upgrade2.php $current_version $next_version > /var/log/$app/upgrade2.html; then
-			ynh_print_info --message="Step 2 upgrading ended successfully"
-		else
-			ynh_die --message="Step 2 upgrading ended with error"
-		fi
-
-		ynh_exec_fully_quiet sleep 5
-
-		if php$phpversion step5.php $current_version $next_version > /var/log/$app/upgrade3.html; then
-			ynh_print_info --message="Step 3 upgrading ended successfully"
-		else
-			ynh_die  --message="Step 3 upgrading ended with error"
-		fi
-
-
-		popd
-
-#REMOVEME? 		ynh_permission_update --permission="main" --remove="visitors"
-
-		# Get the new current version number
-        current_version=$next_version
-        current_major_version=${current_version%%.*}
-
-		done
-
-		if php$phpversion $install_dir/scripts/user/sync_users_ldap2dolibarr.php commitiferror --server=localhost -y; then
-				ynh_print_info --message="LDAP user update ok"
-		else
-				ynh_print_info --message="LDAP user update ended with error"
-		fi
-
-		ynh_app_setting_set --app=$app --key=version --value=$update_version
+if "php$phpversion" "$install_dir/scripts/user/sync_users_ldap2dolibarr.php" commitiferror --server=localhost -y; then
+    ynh_print_info --message="LDAP user update ok"
+else
+    ynh_print_info --message="LDAP user update ended with error"
 fi
 
-#=================================================
-# STORE THE CONFIG FILE CHECKSUM
-#=================================================
-
 ynh_backup_if_checksum_is_different --file="$install_dir/htdocs/conf/conf.php"
 # Recalculate and store the checksum of the file for the next upgrade.
 ynh_store_file_checksum --file="$install_dir/htdocs/conf/conf.php"
 chmod 644 "$install_dir/htdocs/conf/conf.php"
 
-#=================================================
-# SETUP LOGROTATE
-#=================================================
-ynh_script_progression --message="Upgrading logrotate configuration..." --weight=1
-
-# Use logrotate to manage app-specific logfile(s)
-ynh_use_logrotate --non-append
-
-#=================================================
-# GENERIC FINALIZATION
 #=================================================
 # SECURE FILES AND DIRECTORIES
 #=================================================
@@ -275,16 +95,20 @@ chmod 750 "$install_dir"
 chmod -R o-rwx "$install_dir"
 chown -R $app:www-data "$install_dir"
 
-mkdir -p "$data_dir"
-chown -R $app: "$data_dir"
-chmod go-w $data_dir
+# mkdir -p "$data_dir"
+# chown -R $app: "$data_dir"
+# chmod go-w $data_dir
 
 #=================================================
-# RELOAD NGINX
+# REAPPLY SYSTEM CONFIGURATIONS
 #=================================================
-#REMOVEME? ynh_script_progression --message="Reloading NGINX web server..." --weight=1
+ynh_script_progression --message="Upgrading system configurations related to $app..." --weight=1
 
-#REMOVEME? ynh_systemd_action --service_name=nginx --action=reload
+ynh_add_fpm_config
+
+ynh_add_nginx_config
+
+ynh_use_logrotate --non-append
 
 #=================================================
 # END OF SCRIPT
diff --git a/scripts/upgrade.d/upgrade.10.sh b/scripts/upgrade.d/upgrade.10.sh
deleted file mode 100644
index 4099105..0000000
--- a/scripts/upgrade.d/upgrade.10.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-
-# Target version of the Dolibarr update
-next_version="11.0.5"
-
-# Dolibarr tarball checksum
-dolibarr_source_sha256="6f51435a4ffe576e836bf6449d900de9a56016f09591322cb2ba47a07c97679d"
\ No newline at end of file
diff --git a/scripts/upgrade.d/upgrade.11.sh b/scripts/upgrade.d/upgrade.11.sh
deleted file mode 100644
index b7d4982..0000000
--- a/scripts/upgrade.d/upgrade.11.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-
-# Target version of the Dolibarr update
-next_version="12.0.5"
-
-# Dolibarr tarball checksum
-dolibarr_source_sha256="b60b124ebcd294375f6200cc0683449e475b5dec687f8317b820fc8ec1413d21"
\ No newline at end of file
diff --git a/scripts/upgrade.d/upgrade.12.sh b/scripts/upgrade.d/upgrade.12.sh
deleted file mode 100644
index 0dd40d7..0000000
--- a/scripts/upgrade.d/upgrade.12.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-
-# Target version of the Dolibarr update
-next_version="13.0.5"
-
-# Dolibarr tarball checksum
-dolibarr_source_sha256="08ec08dc5093d614361f273237f5aaf8d70e63d764c2fa8d7f3f68a1485156d0"
\ No newline at end of file
diff --git a/scripts/upgrade.d/upgrade.13.sh b/scripts/upgrade.d/upgrade.13.sh
deleted file mode 100644
index 26366cd..0000000
--- a/scripts/upgrade.d/upgrade.13.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-
-# Target version of the Dolibarr update
-next_version="14.0.5"
-
-# Dolibarr tarball checksum
-dolibarr_source_sha256="31f4c934e484a9582d8867e4170f1f1acd8c41628b059370a6a449eb6e94ae75"
\ No newline at end of file
diff --git a/scripts/upgrade.d/upgrade.14.sh b/scripts/upgrade.d/upgrade.14.sh
deleted file mode 100644
index e22383d..0000000
--- a/scripts/upgrade.d/upgrade.14.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-
-# Target version of the Dolibarr update
-next_version="15.0.3"
-
-# Dolibarr tarball checksum
-dolibarr_source_sha256="b145a38f56c44b166721d64909fb12408c6d10d08fcf74d2c00418a60201cc9d"
\ No newline at end of file
diff --git a/scripts/upgrade.d/upgrade.15.sh b/scripts/upgrade.d/upgrade.15.sh
deleted file mode 100644
index c47eca1..0000000
--- a/scripts/upgrade.d/upgrade.15.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-
-# Target version of the Dolibarr update
-next_version="16.0.5"
-
-# Dolibarr tarball checksum
-dolibarr_source_sha256="C8298342558E62B955A6F4C01FEDB6A187B2E0C0B2C1681A97158CA979F9304F"
diff --git a/scripts/upgrade.d/upgrade.16.sh b/scripts/upgrade.d/upgrade.16.sh
deleted file mode 100644
index e5f638a..0000000
--- a/scripts/upgrade.d/upgrade.16.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-
-# Target version of the Dolibarr update
-next_version="17.0.1"
-
-# Dolibarr tarball checksum
-dolibarr_source_sha256="2EDDD545C07EAE291AD46E48AB55D3ADB988D99C29A8DFAA2E2FDE0A890B0DDC"
\ No newline at end of file
diff --git a/scripts/upgrade.d/upgrade.17.sh b/scripts/upgrade.d/upgrade.17.sh
deleted file mode 100644
index 8880793..0000000
--- a/scripts/upgrade.d/upgrade.17.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-
-# Target version of the Dolibarr update
-next_version="18.0.1"
-
-# Dolibarr tarball checksum
-dolibarr_source_sha256="37bd3c8533b821c241dbb34b0e88349c1d5b43f7ffa6027f0b7970748d1f727a"
diff --git a/scripts/upgrade.d/upgrade.9.sh b/scripts/upgrade.d/upgrade.9.sh
deleted file mode 100644
index 0ff52ac..0000000
--- a/scripts/upgrade.d/upgrade.9.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-
-# Target version of the Dolibarr update
-next_version="10.0.7"
-
-# Dolibarr tarball checksum
-dolibarr_source_sha256="6efc230f400a7b7152a0e4b9ba02a780f38b869b4aebd2bc28883268270ef871"
\ No newline at end of file
diff --git a/scripts/upgrade.d/upgrade.last.sh b/scripts/upgrade.d/upgrade.last.sh
deleted file mode 100644
index e73e59d..0000000
--- a/scripts/upgrade.d/upgrade.last.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-
-# Target version of the Dolibarr update
-next_version="18.0.3"
-
-# Dolibarr tarball checksum
-dolibarr_source_sha256="8639d466b26f0fba7d2b610a96ffcf36a657b1e00bdc2e5a1ac5287521dcb4ed"