diff --git a/.github/actions/build-docs/action.yml b/.github/actions/build-docs/action.yml
new file mode 100644
index 0000000000..fa6ab4f6ef
--- /dev/null
+++ b/.github/actions/build-docs/action.yml
@@ -0,0 +1,11 @@
+name: Build Sphinx docs
+description: Requires the setup-idaes action to be run before this
+# TODO add options as inputs as needed
+runs:
+  using: "composite"
+  steps:
+    - name: Build Sphinx docs (HTML)
+      shell: bash
+      run: |
+        cd docs/
+        python build.py
diff --git a/.github/actions/pylint/action.yml b/.github/actions/pylint/action.yml
new file mode 100644
index 0000000000..a047dc52ed
--- /dev/null
+++ b/.github/actions/pylint/action.yml
@@ -0,0 +1,19 @@
+name: Run pylint
+description: Run static analysis using pylint
+# TODO add inputs (options) as needed
+runs:
+  using: "composite"
+  steps:
+    - name: Install pylint dependencies
+      shell: bash
+      run: |
+        PIP_INSTALL="pip --no-cache-dir install --progress-bar off"
+        $PIP_INSTALL --upgrade pip setuptools wheel
+        # TODO the pylint version will have to be pinned
+        # TODO installing idaes is necessary in our case because we import some idaes code in pylint plugins
+        $PIP_INSTALL pylint -r requirements.txt
+        # don't think we need to install the extensions, though
+    - name: Run pylint (errors only)
+      shell: bash
+      run: |
+        pylint -E --ignore-patterns="test_.*" idaes || true
diff --git a/.github/actions/setup-idaes/action.yml b/.github/actions/setup-idaes/action.yml
new file mode 100644
index 0000000000..aa4d045855
--- /dev/null
+++ b/.github/actions/setup-idaes/action.yml
@@ -0,0 +1,36 @@
+name: Set up IDAES
+description: Install IDAES and extensions
+inputs:
+  install-target:
+    description: 'Command-line arguments and options to pass to the install command, e.g. pip install'
+    required: true
+  install-command:
+    description: 'Command to use to install `install-target`'
+    required: false
+    default: pip --no-cache-dir install --progress-bar off
+runs:
+  using: "composite"
+  steps:
+    - name: Update pip and other packaging tools
+      shell: bash
+      run: |
+        ${{ inputs.install-command }} pip setuptools wheel
+    - name: Install idaes and dependencies
+      shell: bash
+      run: |
+        ${{ inputs.install-command }} ${{ inputs.install-target}}
+        idaes --version
+    - name: Install extensions
+      shell: bash
+      run: |
+        idaes get-extensions --verbose
+        # add bin directory to $PATH (only valid for subsequent steps)
+        echo "$(idaes bin-directory)" >> $GITHUB_PATH
+    - name: Test access to executables
+      shell: bash
+      run: |
+        if [ "$RUNNER_OS" == "Windows" ]; then
+            ipopt.exe -v
+        else
+            ipopt -v
+        fi
diff --git a/.github/scripts/countApproved.js b/.github/scripts/countApproved.js
new file mode 100644
index 0000000000..ac3c40d727
--- /dev/null
+++ b/.github/scripts/countApproved.js
@@ -0,0 +1,32 @@
+const REVIEW_STATE = {
+  dismissed: "DISMISSED",
+  approved: "APPROVED",
+};
+
+function selectLatestPerUser(reviews) {
+  const latestByUser = {};
+  reviews.forEach((r) => {
+    // the reviews are in chronological order (earliest to latest)
+    // so to get the latest for each user we can use an Object as a map and loop over all reviews
+    // at each iteration, a more recent review for that user will replace an earlier one set before it
+    latestByUser[r.user.login] = r;
+  });
+  return Object.values(latestByUser);
+}
+
+module.exports = async ({ github, owner, repo, pullNumber }) => {
+  const { data: reviews } = await github.pulls.listReviews({
+    owner: owner,
+    repo: repo,
+    pull_number: pullNumber,
+  });
+
+  const latestReviews = selectLatestPerUser(reviews);
+  console.log(latestReviews);
+  const countApproved = latestReviews.filter(
+    (r) => r.state === REVIEW_STATE.approved
+  ).length;
+  console.log(`${countApproved} approving reviews`);
+
+  return countApproved;
+};
diff --git a/.github/workflows/integration-tests.yml b/.github/workflows/integration-tests.yml
deleted file mode 100644
index 2c25f87d38..0000000000
--- a/.github/workflows/integration-tests.yml
+++ /dev/null
@@ -1,68 +0,0 @@
-name: Integration tests
-
-on:
-  # for the moment, this workflow needs to be triggered manually
-  workflow_dispatch:
-    inputs:
-      git-ref:
-        description: Git hash (optional)
-        required: false
-  repository_dispatch:
-    # to run this, send a POST API call at repos/IDAES/idaes-pse/dispatches with the specified event_type
-    # e.g. `gh repos/IDAES/idaes-pse/dispatches -F event_type=integration_tests_requested`
-    types: [integration_tests_requested]
-  schedule:
-    # run daily at 5:00 am UTC (12 am ET/9 pm PT)
-    - cron: '0 5 * * *'
-  # TODO add PR when "draft" status is switched off (or absent?)
-
-defaults:
-  run:
-    shell: bash
-
-jobs:
-  integration:
-    name: Integration tests (py=${{ matrix.python-version }}, os=${{ matrix.os }})
-    runs-on: ${{ matrix.os }}
-    strategy:
-      # if fail-fast == true (the default), jobs for the remaining values in the matrix are cancelled
-      fail-fast: false
-      matrix:
-        python-version:
-          - '3.6'
-          - '3.7'
-        os:
-          - ubuntu-18.04
-          - windows-latest
-    steps:
-      - uses: actions/checkout@v2
-      - name: Set up Python
-        uses: actions/setup-python@v2
-        with:
-          python-version: ${{ matrix.python-version }}
-      - name: Install idaes and dependencies
-        run: |
-          python -m pip --no-cache-dir install --progress-bar off .[dev]
-      - name: Install extensions
-        run: |
-          idaes get-extensions --verbose
-          find $(idaes data-directory) -ls
-          # add bin directory to $PATH (only valid for subsequent steps)
-          echo "$(idaes bin-directory)" >> $GITHUB_PATH
-      - name: Test access to executables
-        run: |
-          if [ "$RUNNER_OS" == "Windows" ]; then
-              ipopt.exe -v
-          else
-              ipopt -v
-          fi
-      - name: Run idaes-pse integration tests
-        run: |
-          pytest -m integration idaes/
-      - name: Fetch examples-pse
-        run: |
-          git clone https://github.com/IDAES/examples-pse.git
-      - name: Run examples-pse tests
-        run: |
-          cd examples-pse
-          pytest
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 0000000000..d05f2fff6c
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,102 @@
+name: Main
+
+on:
+  push:
+    branches:
+      # TODO this could also be run when pushing to main, but could end up clogging the CI when merging multiple PRs
+      - rel_*
+  schedule:
+    # run daily at 5:00 am UTC (12 am ET/9 pm PT)
+    - cron: '0 5 * * *'
+  repository_dispatch:
+    # to run this, send a POST API call at repos/IDAES/idaes-pse/dispatches with the specified event_type
+    # e.g. `gh repos/IDAES/idaes-pse/dispatches -F event_type=run_tests`
+    types: [run_tests]
+  workflow_dispatch:
+    inputs:
+      git-ref:
+        description: Git hash (optional)
+        required: false
+
+jobs:
+  pytest:
+    name: All tests (py${{ matrix.python-version }}/${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version:
+          - '3.6'
+          - '3.7'
+        os:
+          - ubuntu-18.04
+          - windows-latest
+    steps:
+      - name: Display debug info
+        run: |
+          echo '${{ toJSON(matrix) }}'
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Set up idaes
+        uses: ./.github/actions/setup-idaes
+        with:
+          install-target: '.'
+      - name: Run pytest (all)
+        run: |
+          pytest
+  build-docs:
+    name: Build Sphinx docs
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.7'
+      - name: Set up idaes
+        uses: ./.github/actions/setup-idaes
+        with:
+          install-target: -r requirements-dev.txt
+      - name: Build Sphinx docs
+        uses: ./.github/actions/build-docs
+      - name: Publish built docs
+        uses: actions/upload-artifact@v2
+        with:
+          name: idaes-pse-docs-html
+          path: docs/build/html/
+          retention-days: 7
+  pylint:
+    name: pylint (errors only)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.7'
+      - name: Run pylint
+        uses: ./.github/actions/pylint
+  pytest-coverage:
+    name: Run pytest with coverage report
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.7'
+      - name: Set up idaes
+        uses: ./.github/actions/setup-idaes
+        with:
+          install-target: -r requirements-dev.txt
+      - name: Run pytest with cov
+        run: |
+          pytest --cov
+      - name: Upload coverage report to Codecov
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+        run: |
+          bash <(curl -s https://codecov.io/bash)
diff --git a/.github/workflows/pr-approved.yml b/.github/workflows/pr-approved.yml
new file mode 100644
index 0000000000..ca20f3ad4f
--- /dev/null
+++ b/.github/workflows/pr-approved.yml
@@ -0,0 +1,68 @@
+name: PR (integration)
+
+on:
+  pull_request:
+    types: [labeled]
+
+jobs:
+  check-skip:
+    name: Check if integration tests should run
+    # NOTE: the name of the special label is hardcoded here
+    # it would be better to extract it to a more global location, e.g. the workflow-level env context,
+    # but the env context is not available in job-level if expressions (only step-level ones)
+    if: contains(github.event.label.name, 'ci:approved')
+    runs-on: ubuntu-latest
+    steps:
+      - name: Notify
+        run: echo "The integration tests will run"
+  pytest:
+    name: Integration tests (py${{ matrix.python-version }}/${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
+    needs: [check-skip]
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version:
+          - '3.6'
+          - '3.7'
+        os:
+          - ubuntu-18.04
+          - windows-latest
+    steps:
+      - name: Display debug info
+        run: |
+          echo '${{ toJSON(matrix) }}'
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Set up idaes
+        uses: ./.github/actions/setup-idaes
+        with:
+          install-target: '.'
+      - name: Run pytest (not integration)
+        run: |
+          pytest -m 'integration'
+  pytest-coverage:
+    name: Run pytest (complete) with coverage report
+    runs-on: ubuntu-latest
+    needs: [check-skip]
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.7'
+      - name: Set up idaes
+        uses: ./.github/actions/setup-idaes
+        with:
+          install-target: -r requirements-dev.txt
+      - name: Run pytest (complete) with cov
+        run: |
+          pytest --cov
+      - name: Upload coverage report to Codecov
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+        run: |
+          bash <(curl -s https://codecov.io/bash)
diff --git a/.github/workflows/pr-review.yml b/.github/workflows/pr-review.yml
new file mode 100644
index 0000000000..116bddb93b
--- /dev/null
+++ b/.github/workflows/pr-review.yml
@@ -0,0 +1,124 @@
+name: PR review
+
+on:
+  pull_request_review:
+    types:
+      - submitted
+      - edited
+      - dismissed
+
+env:
+  PR_APPROVED_LABEL_NAME: 'ci:approved'
+
+jobs:
+  check-approved:
+    name: Check if PR is approved
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check reviews for approval
+        id: check-approved
+        uses: actions/github-script@master
+        with:
+          github-token: ${{ secrets.IDAES_BUILD_TOKEN }}
+          script: |
+            const ReviewState = {
+              dismissed: "DISMISSED",
+              approved: "APPROVED",
+              changesRequested: "CHANGES_REQUESTED",
+              commented: "COMMENTED",
+            };
+            const minCountApproved = 2;
+            const specialReviewer = 'idaes-build';
+            const reviewEvent = context.payload;
+            const pullRequest = reviewEvent.pull_request;
+
+            function prettyPrint(obj, what) {
+              const indent = 2;
+              console.log(`${what}:`);
+              console.log(JSON.stringify(obj, null, indent));
+            }
+
+            // check count of approved reviews after selecting latest for each reviewer
+            async function selectLatestPerUser(reviews) {
+              const latestByUser = {};
+              reviews.forEach((r) => {
+                // the reviews are in chronological order (earliest to latest)
+                // so to get the latest for each user we can use an Object as a map and loop over all reviews
+                // at each iteration, a more recent review for that user will replace an earlier one set before it
+                // "COMMENTED" reviews are skipped since they don't change the approval status
+                if (r.state != ReviewState.commented) {
+                  latestByUser[r.user.login] = r;
+                }
+              });
+              return Object.values(latestByUser);
+            }
+
+            const fetchedReviews = await github.paginate(
+              github.pulls.listReviews, {
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                pull_number: pullRequest.number,
+              })
+              .then(
+               reviews => reviews
+              );
+
+            const countFetched = fetchedReviews.length;
+            const latestFetched = fetchedReviews[fetchedReviews.length - 1];
+            console.log(`Fetched ${countFetched} reviews.`);
+            prettyPrint(latestFetched, 'Latest fetched review');
+
+            const latestReviews = await selectLatestPerUser(fetchedReviews);
+            console.log(`There are ${latestReviews.length} up-to-date reviews from unique reviewers.`);
+
+            const countApproved = latestReviews.filter(r => r.state === ReviewState.approved).length;
+            console.log(`${countApproved} approving reviews (at least ${minCountApproved} required).`);
+            const isApproved = countApproved >= minCountApproved;
+            console.log(`Approved: ${isApproved}`);
+
+
+            async function ensureLabelPresence({labelName, shouldBePresent}) {
+              const commonArgs = {
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: pullRequest.number,
+              };
+              const {data: labels} = await github.issues.listLabelsOnIssue({
+                ...commonArgs
+              });
+              prettyPrint(labels, 'Current labels');
+              const isPresent = labels.filter(label => label.name === labelName).length == 1;
+              const msg = `Label ${labelName} is ${isPresent ? "" : "not"} present, when it should ${shouldBePresent ? "": "not"} be present.`
+              console.log(msg);
+              const alreadyPresent = shouldBePresent && isPresent;
+              const needsAdding = shouldBePresent && !isPresent;
+              const needsRemoving = !shouldBePresent && isPresent;
+              const alreadyAbsent = !shouldBePresent && !isPresent;
+              if (needsAdding) {
+                console.log(`Label ${labelName} will be added.`);
+                await github.issues.addLabels({
+                  ...commonArgs,
+                  labels: [labelName]
+                });
+              } else if (needsRemoving) {
+                console.log(`Label ${labelName} will be removed.`);
+                try {
+                  await github.issues.removeLabel({
+                    ...commonArgs,
+                    name: labelName,
+                  });
+                } catch (error) {
+                  if (error.status === 404) {
+                    console.log(`Could not remove label ${labelName} (label not found).`);
+                    console.log('This is generally not an issue, and is probably due to the label being removed while this workflow was running.');
+                  }
+                }
+              } else if (alreadyPresent || alreadyAbsent) {
+                console.log(`Label ${labelName} is already in desired state, no further action needed.`);
+              }
+            }
+            const labelName = process.env.PR_APPROVED_LABEL_NAME;
+            await ensureLabelPresence({
+              labelName: labelName,
+              shouldBePresent: isApproved,
+            });
diff --git a/.github/workflows/pr.yml b/.github/workflows/pr.yml
new file mode 100644
index 0000000000..c8cfa934fd
--- /dev/null
+++ b/.github/workflows/pr.yml
@@ -0,0 +1,93 @@
+name: PR
+
+on:
+  pull_request:
+    types:
+      # ready_for_review occurs when a PR is opened in non-draft mode,
+      # or when a draft PR is turned to non-draft
+      - ready_for_review
+      # synchronize occurs whenever commits are pushed to the PR branch
+      # - synchronize
+
+jobs:
+  pytest:
+    name: Tests (py${{ matrix.python-version }}/${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version:
+          - '3.6'
+          - '3.7'
+        os:
+          - ubuntu-18.04
+          - windows-latest
+    steps:
+      - name: Display debug info
+        run: |
+          echo '${{ toJSON(matrix) }}'
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Set up idaes
+        uses: ./.github/actions/setup-idaes
+        with:
+          install-target: '.'
+      - name: Run pytest (not integration)
+        run: |
+          pytest -m 'not integration'
+  build-docs:
+    name: Build Sphinx docs
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.7'
+      - name: Set up idaes
+        uses: ./.github/actions/setup-idaes
+        with:
+          install-target: -r requirements-dev.txt
+      - name: Build Sphinx docs
+        uses: ./.github/actions/build-docs
+      - name: Publish built docs
+        uses: actions/upload-artifact@v2
+        with:
+          name: idaes-pse-docs-html
+          path: docs/build/html/
+          retention-days: 7
+  pylint:
+    name: pylint (errors only)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.7'
+      - name: Run pylint
+        uses: ./.github/actions/pylint
+  pytest-coverage:
+    name: Run pytest with coverage report
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.7'
+      - name: Set up idaes
+        uses: ./.github/actions/setup-idaes
+        with:
+          install-target: -r requirements-dev.txt
+      - name: Run pytest (not integration) with cov
+        run: |
+          pytest -m 'not integration' --cov
+      - name: Upload coverage report to Codecov
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+        run: |
+          bash <(curl -s https://codecov.io/bash)
diff --git a/.github/workflows/pull-request-main.yml b/.github/workflows/pull-request-main.yml
deleted file mode 100644
index cf3f689fb0..0000000000
--- a/.github/workflows/pull-request-main.yml
+++ /dev/null
@@ -1,124 +0,0 @@
-name: Pull request (main) CI tests
-
-on:
-  push:
-    branches:
-      - main
-  pull_request:
-    branches:
-      - main
-  workflow_dispatch:
-    inputs:
-      git-ref:
-        description: Git hash (optional)
-        required: false
-
-defaults:
-  run:
-    shell: bash
-
-jobs:
-  run-tests:
-    name: Install and test (py=${{ matrix.python-version }}, os=${{ matrix.os }})
-    runs-on: ${{ matrix.os }}
-    strategy:
-      # if fail-fast == true (the default), jobs for the remaining values in the matrix are cancelled
-      fail-fast: false
-      matrix:
-        python-version:
-          - '3.6'
-          - '3.7'
-        os:
-          - ubuntu-18.04
-          - windows-latest
-    steps:
-      - uses: actions/checkout@v2
-      - name: Set up Python
-        uses: actions/setup-python@v2
-        with:
-          python-version: ${{ matrix.python-version }}
-      - name: Install IDAES with dependencies
-        run: |
-          python -m pip install --progress-bar off -r requirements.txt
-      - name: Display IDAES version
-        run: |
-          idaes --version
-      - name: Install IDAES extensions
-        run: |
-          idaes get-extensions --verbose
-          # TODO: these commands are Unix-shell specific 
-          # and will need to be changed if we want to test on CMD.exe/Powershell
-          find $(idaes data-directory) -ls
-          # add bin directory to $PATH (only valid for subsequent steps)
-          echo "$(idaes bin-directory)" >> $GITHUB_PATH
-      - name: Test access to executables
-        run: |
-          if [ "$RUNNER_OS" == "Windows" ]; then
-              ipopt.exe -v
-          else
-              ipopt -v
-          fi
-      - name: Run tests (excluding integration)
-        run: |
-          pytest -c pytest.ini -m 'not integration' idaes/
-      - name: Run integration tests
-        # if this is a draft PR, skip integration tests
-        # the idea is that it should not be possible for a PR to be merged without integration tests:
-        # either it's a draft PR (and thus can't be merged), or it isn't (and integration tests will not be skipped)
-        if: github.event.pull_request.draft == false
-        run: |
-          pytest -c pytest.ini -m integration idaes/
-      # TODO: pytest --cov
-      # TODO: coveralls (coverage report)
-  build-docs:
-    name: Build Sphinx docs (HTML)
-    runs-on: ubuntu-18.04
-    steps:
-    - uses: actions/checkout@v2
-    - name: Set up Python
-      uses: actions/setup-python@v2
-      with:
-        python-version: '3.7'
-    - name: Install Sphinx dependencies
-      run: |
-        # idaes and the modules in idaes.__init__ are imported when accessing idaes.ver
-        python -m pip --no-cache-dir install --progress-bar off -r requirements-dev.txt
-    - name: Install IDAES extensions
-      run: |
-        idaes get-extensions --verbose
-        find $(idaes data-directory) -ls
-        # add bin directory to $PATH (only valid for subsequent steps)
-        echo "$(idaes bin-directory)" >> $GITHUB_PATH
-    - name: Test access to executables
-      run: |
-        ipopt -v
-    - name: Build Sphinx docs
-      run: |
-        cd docs/
-        python build.py
-    - name: Publish built docs
-      uses: actions/upload-artifact@v2
-      with:
-        name: idaes-pse-docs-html
-        path: docs/build/html/
-        retention-days: 7
-  pylint:
-    name: Run pylint (errors only)
-    runs-on: ubuntu-18.04
-    steps:
-    - uses: actions/checkout@v2
-    - name: Set up Python
-      uses: actions/setup-python@v2
-      with:
-        python-version: '3.7'
-    - name: Install pylint dependencies
-      run: |
-        # TODO pylint and astroid versions will need to be pinned
-        python -m pip --no-cache-dir install --progress-bar off pylint
-        # in general the package being pylinted does not need to be installed to run pylint on it
-        # but in our case the pylint plugin needs to be able to import some code from idaes and pyomo
-        python -m pip --no-cache-dir install --progress-bar off -r requirements.txt
-    - name: Run pylint
-      run: |
-        pylint -E --ignore-patterns="test_.*" idaes || true
-