diff --git a/tools/release/build_delivery_mac.sh b/tools/release/build_delivery_mac.sh
index 74af4d732b..1911c5ee36 100755
--- a/tools/release/build_delivery_mac.sh
+++ b/tools/release/build_delivery_mac.sh
@@ -1,163 +1,321 @@
 #!/usr/bin/env bash
-set -euxo pipefail
+set -eo pipefail
 
-if [[ -z "${DOTNET_SNK}" ]]; then
-  echo "DOTNET_SNK: not found !" | tee build.log
-  exit 1
-fi
+function help() {
+  local -r NAME=$(basename "$0")
+  local -r BOLD="\e[1m"
+  local -r RESET="\e[0m"
+  local -r help=$(cat << EOF
+${BOLD}NAME${RESET}
+\t$NAME - Build delivery using the ${BOLD}local host system${RESET}.
+${BOLD}SYNOPSIS${RESET}
+\t$NAME [-h|--help] [examples|dotnet|java|all]
+${BOLD}DESCRIPTION${RESET}
+\tBuild Google OR-Tools deliveries.
+\tYou ${BOLD}MUST${RESET} define the following variables before running this script:
+\t* ORTOOLS_TOKEN: secret use to decrypt key to sign dotent and java package.
 
-if [[ -z "${ORTOOLS_TOKEN}" ]]; then
-  echo "ORTOOLS_TOKEN: not found !" | tee build.log
-  exit 1
-fi
+${BOLD}OPTIONS${RESET}
+\t-h --help: show this help text
+\tdotnet: Build dotnet packages
+\tjava: Build java packages
+\texamples: Build examples archives
+\tall: build everything (default)
 
-# Clean everything
-make clean
-make clean_third_party
+${BOLD}EXAMPLES${RESET}
+Using export to define the ${BOLD}ORTOOLS_TOKEN${RESET} env and only building the Java packages:
+export ORTOOLS_TOKEN=SECRET
+$0 java
 
-# Print version
-make print-OR_TOOLS_VERSION | tee build.log
+note: the 'export ...' should be placed in your bashrc to avoid leak of the secret
+in your bash history
+EOF
+)
+echo -e "$help"
+}
 
-# Check all prerequisite
-# cc
-command -v clang
-command -v clang | xargs echo "clang: " | tee -a build.log
-command -v cmake
-command -v cmake | xargs echo "cmake: " | tee -a build.log
-command -v make
-command -v make | xargs echo "make: " | tee -a build.log
+function assert_defined(){
+  if [[ -z "${!1}" ]]; then
+    >&2 echo "Variable '${1}' must be defined"
+    exit 1
+  fi
+}
 
-command -v swig
-command -v swig | xargs echo "swig: " | tee -a build.log
+function build_cxx() {
+  if echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" | cmp --silent "${ROOT_DIR}/export/cxx_build" -; then
+    echo "build C++ up to date!"
+    return 0
+  fi
 
-# python
-PY=(3.6 3.7 3.8 3.9)
-for i in "${PY[@]}"; do
-  command -v "python$i"
-  command -v "python$i" | xargs echo "python$i: " | tee -a build.log
-  "python$i" -c "import distutils.util as u; print(u.get_platform())" | tee -a build.log
-  "python$i" -m pip install --user wheel absl-py mypy-protobuf
-done
-command -v protoc-gen-mypy | xargs echo "protoc-gen-mypy: " | tee -a build.log
+  # Check all prerequisite
+  command -v clang
+  command -v clang | xargs echo "clang: " | tee -a build.log
+  command -v cmake
+  command -v cmake | xargs echo "cmake: " | tee -a build.log
+  command -v make
+  command -v make | xargs echo "make: " | tee -a build.log
 
-# java
-# maven require JAVA_HOME
-if [[ -z "${JAVA_HOME}" ]]; then
-  echo "JAVA_HOME: not found !" | tee build.log
-  exit 1
-else
-  echo "JAVA_HOME: ${JAVA_HOME}" | tee -a build.log
-  command -v java
-  command -v java | xargs echo "java: " | tee -a build.log
-  command -v javac
-  command -v javac | xargs echo "javac: " | tee -a build.log
-  command -v jar
-  command -v jar | xargs echo "jar: " | tee -a build.log
-  command -v mvn
-  command -v mvn | xargs echo "mvn: " | tee -a build.log
-  java -version 2>&1 | head -n 1 | grep 1.8
-fi
-# Maven central need gpg sign and we store the release key encoded using openssl
-command -v openssl
-command -v openssl | xargs echo "openssl: " | tee -a build.log
-command -v gpg
-command -v gpg | xargs echo "gpg: " | tee -a build.log
+  # Clean everything
+  cd "${ROOT_DIR}" || exit 2
+  make clean
+  make clean_third_party
 
-#.Net
-command -v dotnet
-command -v dotnet | xargs echo "dotnet: " | tee -a build.log
+  #  Build Third Party
+  echo -n "Build Third Party..." | tee -a build.log
+  make third_party UNIX_PYTHON_VER=3.9
+  echo "DONE" | tee -a build.log
 
-###############################
-##  Build Examples Archives  ##
-###############################
-rm -rf temp ./*.tar.gz
-echo -n "Build examples archives..." | tee -a build.log
-echo -n "  C++ examples archive..." | tee -a build.log
-make cc_examples_archive UNIX_PYTHON_VER=3.9
-echo -n "  Python examples archive..." | tee -a build.log
-make python_examples_archive UNIX_PYTHON_VER=3.9
-echo -n "  Java examples archive..." | tee -a build.log
-make java_examples_archive UNIX_PYTHON_VER=3.9
-echo -n "  .Net examples archive..." | tee -a build.log
-make dotnet_examples_archive UNIX_PYTHON_VER=3.9
-echo "DONE" | tee -a build.log
+  echo -n "Build C++..." | tee -a build.log
+  make cc -l 4 UNIX_PYTHON_VER=3.9
+  echo "DONE" | tee -a build.log
+  #make test_cc -l 4 UNIX_PYTHON_VER=3.9
+  #echo "make test_cc: DONE" | tee -a build.log
 
-#########################
-##  Build Third Party  ##
-#########################
-echo -n "Build Third Party..." | tee -a build.log
-make third_party UNIX_PYTHON_VER=3.9
-echo "DONE" | tee -a build.log
+  echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" > "${ROOT_DIR}/export/cxx_build"
+}
 
-########################
-##  Install Java gpg  ##
-########################
-echo -n "Install Java gpg" | tee -a build.log
-openssl aes-256-cbc -iter 42 -pass pass:$ORTOOLS_TOKEN -in tools/release/private-key.gpg.enc -out private-key.gpg -d
-gpg --batch --import private-key.gpg
-mkdir -p ~/.m2
-openssl aes-256-cbc -iter 42 -pass pass:$ORTOOLS_TOKEN -in tools/release/settings.xml.enc -out ~/.m2/settings.xml -d
-echo "DONE" | tee -a build.log
+# Net build
+function build_dotnet() {
+  if echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" | cmp --silent "${ROOT_DIR}/export/dotnet_build" -; then
+    echo "build .Net up to date!"
+    return 0
+  fi
+  build_cxx
 
-#####################
-##  C++/Java/.Net  ##
-#####################
-echo -n "Build C++..." | tee -a build.log
-make cc -l 4 UNIX_PYTHON_VER=3.9
-echo "DONE" | tee -a build.log
-#make test_cc -l 4 UNIX_PYTHON_VER=3.9
-#echo "make test_cc: DONE" | tee -a build.log
+  command -v swig
+  command -v swig | xargs echo "swig: " | tee -a build.log
+  command -v dotnet
+  command -v dotnet | xargs echo "dotnet: " | tee -a build.log
 
-echo -n "Build flatzinc..." | tee -a build.log
-make fz -l 4 UNIX_PYTHON_VER=3.9
-echo "DONE" | tee -a build.log
+  # Install .Net SNK
+  echo -n "Install .Net snk" | tee -a build.log
+  openssl aes-256-cbc -iter 42 -pass pass:$ORTOOLS_TOKEN \
+    -in ${RELEASE_DIR}/or-tools.snk.enc \
+    -out ${ROOT_DIR}/export/or-tools.snk -d
+  DOTNET_SNK=export/or-tools.snk
+  echo "DONE" | tee -a build.log
 
-echo -n "Build Java..." | tee -a build.log
-make java -l 4 UNIX_PYTHON_VER=3.9
-echo "DONE" | tee -a build.log
-#make test_java -l 4 UNIX_PYTHON_VER=3.9
-#echo "make test_java: DONE" | tee -a build.log
+  # Clean dotnet
+  cd "${ROOT_DIR}" || exit 2
+  make clean_dotnet
 
-echo -n "Build .Net..." | tee -a build.log
-make dotnet -l 4 UNIX_PYTHON_VER=3.9
-echo "DONE" | tee -a build.log
-#make test_dotnet -l 4 UNIX_PYTHON_VER=3.9
-#echo "make test_dotnet: DONE" | tee -a build.log
+  echo -n "Build .Net..." | tee -a build.log
+  make dotnet -l 4 UNIX_PYTHON_VER=3.9
+  echo "DONE" | tee -a build.log
+  #make test_dotnet -l 4 UNIX_PYTHON_VER=3.9
+  #echo "make test_dotnet: DONE" | tee -a build.log
+
+  cp packages/*nupkg export/
+  echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" > "${ROOT_DIR}/export/dotnet_build"
+}
+
+# Java build
+function build_java() {
+  if echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" | cmp --silent "${ROOT_DIR}/export/java_build" -; then
+    echo "build Java up to date!"
+    return 0
+  fi
+  build_cxx
+
+  command -v swig
+  command -v swig | xargs echo "swig: " | tee -a build.log
+  # maven require JAVA_HOME
+  if [[ -z "${JAVA_HOME}" ]]; then
+    echo "JAVA_HOME: not found !" | tee build.log
+    exit 1
+  else
+    echo "JAVA_HOME: ${JAVA_HOME}" | tee -a build.log
+    command -v java
+    command -v java | xargs echo "java: " | tee -a build.log
+    command -v javac
+    command -v javac | xargs echo "javac: " | tee -a build.log
+    command -v jar
+    command -v jar | xargs echo "jar: " | tee -a build.log
+    command -v mvn
+    command -v mvn | xargs echo "mvn: " | tee -a build.log
+    java -version 2>&1 | head -n 1 | grep 1.8
+  fi
+  # Maven central need gpg sign and we store the release key encoded using openssl
+  command -v openssl
+  command -v openssl | xargs echo "openssl: " | tee -a build.log
+  command -v gpg
+  command -v gpg | xargs echo "gpg: " | tee -a build.log
+
+  # Install Java GPG
+  echo -n "Install Java gpg" | tee -a build.log
+  openssl aes-256-cbc -iter 42 -pass pass:$ORTOOLS_TOKEN -in tools/release/private-key.gpg.enc -out private-key.gpg -d
+  gpg --batch --import private-key.gpg
+  # Don't need to trust the key
+  #expect -c "spawn gpg --edit-key "corentinl@google.com" trust quit; send \"5\ry\r\"; expect eof"
+
+  # Install the maven settings.xml having the GPG passphrase
+  mkdir -p ~/.m2
+  openssl aes-256-cbc -iter 42 -pass pass:$ORTOOLS_TOKEN -in tools/release/settings.xml.enc -out ~/.m2/settings.xml -d
+  echo "DONE" | tee -a build.log
+
+  # Clean java
+  cd "${ROOT_DIR}" || exit 2
+  make clean_java
+
+  echo -n "Build Java..." | tee -a build.log
+  make java -l 4 UNIX_PYTHON_VER=3.9
+  echo "DONE" | tee -a build.log
+  #make test_java -l 4 UNIX_PYTHON_VER=3.9
+  #echo "make test_java: DONE" | tee -a build.log
+
+  cp temp_java/ortools-linux-x86-64/target/*.jar* export/
+  cp temp_java/ortools-java/target/*.jar* export/
+  echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" > "${ROOT_DIR}/export/java_build"
+}
+
+function build_fz() {
+  if echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" | cmp --silent "${ROOT_DIR}/export/fz_build" -; then
+    echo "build Flatzinc up to date!"
+    return 0
+  fi
+  build_cxx
+
+  # Clean fz
+  cd "${ROOT_DIR}" || exit 2
+  make clean_fz
+
+  echo -n "Build flatzinc..." | tee -a build.log
+  make fz -l 4 UNIX_PYTHON_VER=3.9
+  echo "DONE" | tee -a build.log
+
+  echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" > "${ROOT_DIR}/export/fz_build"
+}
 
 # Create Archive
-echo -n "Make archive..." | tee -a build.log
-make archive UNIX_PYTHON_VER=3.9
-echo "DONE" | tee -a build.log
-echo -n "Test archive..." | tee -a build.log
-make test_archive UNIX_PYTHON_VER=3.9
-echo "DONE" | tee -a build.log
+function build_archive() {
+  if echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" | cmp --silent "${ROOT_DIR}/export/archive_build" -; then
+    echo "build archive up to date!"
+    return 0
+  fi
+  build_fz
 
-echo -n "Make flatzinc archive..." | tee -a build.log
-make fz_archive UNIX_PYTHON_VER=3.9
-echo "DONE" | tee -a build.log
-echo -n "Test flatzinc archive..." | tee -a build.log
-make test_fz_archive UNIX_PYTHON_VER=3.9
-echo "DONE" | tee -a build.log
+  # Clean archive
+  cd "${ROOT_DIR}" || exit 2
+  make clean_archive
 
-##################
-##  Python 3.X  ##
-##################
-for i in "${PY[@]}"; do
-  echo -n "Cleaning Python..." | tee -a build.log
-  make clean_python UNIX_PYTHON_VER="$i"
+  echo -n "Make archive..." | tee -a build.log
+  make archive UNIX_PYTHON_VER=3.9
+  echo "DONE" | tee -a build.log
+  echo -n "Test archive..." | tee -a build.log
+  make test_archive UNIX_PYTHON_VER=3.9
   echo "DONE" | tee -a build.log
 
-  echo -n "Build Python $i..." | tee -a build.log
-  make python -l 4 UNIX_PYTHON_VER="$i"
+  echo -n "Make flatzinc archive..." | tee -a build.log
+  make fz_archive UNIX_PYTHON_VER=3.9
   echo "DONE" | tee -a build.log
-  #make test_python UNIX_PYTHON_VER=$i
-  #echo "make test_python$i: DONE" | tee -a build.log
-  echo -n "Build Python $i wheel archive..." | tee -a build.log
-  make package_python UNIX_PYTHON_VER="$i"
-  echo "DONE" | tee -a build.log
-  echo -n "Test Python $i wheel archive..." | tee -a build.log
-  make test_package_python UNIX_PYTHON_VER="$i"
+  echo -n "Test flatzinc archive..." | tee -a build.log
+  make test_fz_archive UNIX_PYTHON_VER=3.9
   echo "DONE" | tee -a build.log
 
-  cp "temp_python$i"/ortools/dist/*.whl .
-done
+  # TODO(mizux) copy archives to export/
+  echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" > "${ROOT_DIR}/export/archive_build"
+}
+
+# Build Examples
+function build_examples() {
+  if echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" | cmp --silent "${ROOT_DIR}/export/examples_build" -; then
+    echo "build examples up to date!"
+    return 0
+  fi
+
+  cd "${ROOT_DIR}" || exit 2
+
+  rm -rf temp ./*.tar.gz
+  echo -n "Build examples archives..." | tee -a build.log
+  echo -n "  C++ examples archive..." | tee -a build.log
+  make cc_examples_archive UNIX_PYTHON_VER=3.9
+  echo -n "  Python examples archive..." | tee -a build.log
+  make python_examples_archive UNIX_PYTHON_VER=3.9
+  echo -n "  Java examples archive..." | tee -a build.log
+  make java_examples_archive UNIX_PYTHON_VER=3.9
+  echo -n "  .Net examples archive..." | tee -a build.log
+  make dotnet_examples_archive UNIX_PYTHON_VER=3.9
+  echo "DONE" | tee -a build.log
+
+  # TODO(mizux) copy example to export/
+  echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" > "${ROOT_DIR}/export/examples_build"
+}
+
+# Python 3
+# todo(mizux) Use `make --directory tools/docker python` instead
+function build_python() {
+  build_cxx
+
+  command -v swig
+  command -v swig | xargs echo "swig: " | tee -a build.log
+  PY=(3.6 3.7 3.8 3.9)
+  for i in "${PY[@]}"; do
+    command -v "python$i"
+    command -v "python$i" | xargs echo "python$i: " | tee -a build.log
+    "python$i" -c "import distutils.util as u; print(u.get_platform())" | tee -a build.log
+    "python$i" -m pip install --user wheel absl-py mypy-protobuf
+  done
+  command -v protoc-gen-mypy | xargs echo "protoc-gen-mypy: " | tee -a build.log
+
+  for i in "${PY[@]}"; do
+    echo -n "Cleaning Python 3..." | tee -a build.log
+    make clean_python UNIX_PYTHON_VER=$i
+    echo "DONE" | tee -a build.log
+
+    echo -n "Build Python $i..." | tee -a build.log
+    make python -l 4 UNIX_PYTHON_VER=$i
+    echo "DONE" | tee -a build.log
+    #make test_python UNIX_PYTHON_VER=$i
+    #echo "make test_python$i: DONE" | tee -a build.log
+    echo -n "Build Python $i wheel archive..." | tee -a build.log
+    make package_python UNIX_PYTHON_VER=$i
+    echo "DONE" | tee -a build.log
+    echo -n "Test Python $i wheel archive..." | tee -a build.log
+    make test_package_python UNIX_PYTHON_VER=$i
+    echo "DONE" | tee -a build.log
+
+    cp "temp_python$i"/ortools/dist/*.whl export/
+  done
+  echo "${ORTOOLS_BRANCH} ${ORTOOLS_SHA1}" > "${ROOT_DIR}/export/python_build"
+}
+
+# Main
+function main() {
+  case ${1} in
+    -h | --help)
+      help; exit ;;
+  esac
+
+  assert_defined ORTOOLS_TOKEN
+  echo "ORTOOLS_TOKEN: FOUND" | tee build.log
+  make print-OR_TOOLS_VERSION | tee -a build.log
+
+  declare -r ROOT_DIR="$(cd -P -- "$(dirname -- "$0")/../.." && pwd -P)"
+  echo "ROOT_DIR: '${ROOT_DIR}'"
+  declare -r RELEASE_DIR="$(cd -P -- "$(dirname -- "$0")" && pwd -P)"
+  echo "RELEASE_DIR: '${RELEASE_DIR}'"
+
+  local -r ORTOOLS_BRANCH=$(git rev-parse --abbrev-ref HEAD)
+  local -r ORTOOLS_SHA1=$(git rev-parse --verify HEAD)
+  mkdir -p export
+
+  case ${1} in
+    cxx|dotnet|java|python|archive|examples)
+      "build_$1"
+      exit ;;
+    all)
+      build_dotnet
+      build_java
+      #build_python
+      build_archive
+      build_examples
+      exit ;;
+    *)
+      >&2 echo "Target '${1}' unknown"
+      exit 1
+  esac
+  exit 0
+}
+
+main "${1:-all}"
+