diff --git a/build.gradle b/build.gradle
index 9fa1c4d9b34..2b33236acd4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -125,8 +125,6 @@ dependencies {
 
     compile 'commons-logging:commons-logging:1.2'
 
-    compile 'org.apache.commons:commons-lang3:3.6'
-
     compile 'org.jsoup:jsoup:1.10.3'
     compile 'com.mashape.unirest:unirest-java:1.4.9'
     compile 'info.debatty:java-string-similarity:0.24'
@@ -152,6 +150,9 @@ dependencies {
     testCompile 'com.github.tomakehurst:wiremock:2.6.0'
     testCompile 'org.assertj:assertj-swing-junit:3.6.0'
     testCompile 'org.reflections:reflections:0.9.11'
+
+    testCompile 'com.tngtech.archunit:archunit-junit:0.4.0'
+    testCompile 'org.slf4j:slf4j-jcl:1.7.25' // required by ArchUnit to enable logging over jcl
 }
 
 sourceSets {
diff --git a/external-libraries.txt b/external-libraries.txt
index d303befdbbe..1bf47425154 100644
--- a/external-libraries.txt
+++ b/external-libraries.txt
@@ -1,6 +1,9 @@
 This document lists the fonts, icons, and libraries used by JabRef.
 This file is manually kept in sync with build.gradle and the binary jars contained in the lib/ directory.
 
+One can list all depdencies by using Gradle task `depdencyReport`.
+It generated the file [build/reports/project/dependencies.txt](build/reports/project/dependencies.txt).
+
 # Legend
 
 ## License
diff --git a/src/main/java/org/jabref/Globals.java b/src/main/java/org/jabref/Globals.java
index 3c5cdad55f0..7e404d1d31c 100644
--- a/src/main/java/org/jabref/Globals.java
+++ b/src/main/java/org/jabref/Globals.java
@@ -16,10 +16,10 @@
 import org.jabref.logic.util.BuildInfo;
 import org.jabref.preferences.JabRefPreferences;
 
+import com.google.common.base.StandardSystemProperty;
 import com.microsoft.applicationinsights.TelemetryClient;
 import com.microsoft.applicationinsights.TelemetryConfiguration;
 import com.microsoft.applicationinsights.telemetry.SessionState;
-import org.apache.commons.lang3.SystemUtils;
 
 public class Globals {
 
@@ -87,11 +87,11 @@ private static void startTelemetryClient() {
         telemetryConfiguration.setTrackingIsDisabled(!Globals.prefs.shouldCollectTelemetry());
         telemetryClient = new TelemetryClient(telemetryConfiguration);
         telemetryClient.getContext().getProperties().put("JabRef version", Globals.BUILD_INFO.getVersion().toString());
-        telemetryClient.getContext().getProperties().put("Java version", SystemUtils.JAVA_RUNTIME_VERSION);
+        telemetryClient.getContext().getProperties().put("Java version", StandardSystemProperty.JAVA_VERSION.value());
         telemetryClient.getContext().getUser().setId(Globals.prefs.getOrCreateUserId());
         telemetryClient.getContext().getSession().setId(UUID.randomUUID().toString());
-        telemetryClient.getContext().getDevice().setOperatingSystem(SystemUtils.OS_NAME);
-        telemetryClient.getContext().getDevice().setOperatingSystemVersion(SystemUtils.OS_VERSION);
+        telemetryClient.getContext().getDevice().setOperatingSystem(StandardSystemProperty.OS_NAME.value());
+        telemetryClient.getContext().getDevice().setOperatingSystemVersion(StandardSystemProperty.OS_VERSION.value());
         telemetryClient.getContext().getDevice().setScreenResolution(
                 Toolkit.getDefaultToolkit().getScreenSize().toString());
 
diff --git a/src/main/java/org/jabref/architecture/ApacheCommonsLang3Allowed.java b/src/main/java/org/jabref/architecture/ApacheCommonsLang3Allowed.java
new file mode 100644
index 00000000000..f398c11f56e
--- /dev/null
+++ b/src/main/java/org/jabref/architecture/ApacheCommonsLang3Allowed.java
@@ -0,0 +1,12 @@
+package org.jabref.architecture;
+
+/**
+ * Annotation to indicate that usage of ApacheCommonsLang3 is explicitly allowed.
+ * The intention is to fully switch to Google Guava and only use Apache Commons Lang3 if there is no other possibility
+ */
+public @interface ApacheCommonsLang3Allowed {
+
+    // The rationale
+    String value();
+
+}
diff --git a/src/main/java/org/jabref/cli/ArgumentProcessor.java b/src/main/java/org/jabref/cli/ArgumentProcessor.java
index 1d11dcc723f..8ddcb93dd52 100644
--- a/src/main/java/org/jabref/cli/ArgumentProcessor.java
+++ b/src/main/java/org/jabref/cli/ArgumentProcessor.java
@@ -51,7 +51,7 @@
 import org.jabref.preferences.SearchPreferences;
 import org.jabref.shared.prefs.SharedDatabasePreferences;
 
-import org.apache.commons.lang3.exception.ExceptionUtils;
+import com.google.common.base.Throwables;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
@@ -273,7 +273,7 @@ private boolean exportMatches(List<ParserResult> loaded) {
                             matches);
                 } catch (Exception ex) {
                     System.err.println(Localization.lang("Could not export file") + " '" + data[1] + "': "
-                            + ExceptionUtils.getStackTrace(ex));
+                            + Throwables.getStackTraceAsString(ex));
                 }
             }
         } else {
@@ -451,7 +451,7 @@ private void exportFile(List<ParserResult> loaded, String[] data) {
                 } catch (Exception ex) {
 
                     System.err.println(Localization.lang("Could not export file") + " '" + data[0] + "': "
-                            + ExceptionUtils.getStackTrace(ex));
+                            + Throwables.getStackTraceAsString(ex));
                 }
             }
 
diff --git a/src/main/java/org/jabref/gui/errorconsole/LogEventViewModel.java b/src/main/java/org/jabref/gui/errorconsole/LogEventViewModel.java
index b3e0ec1dfcd..dd906d3c30b 100644
--- a/src/main/java/org/jabref/gui/errorconsole/LogEventViewModel.java
+++ b/src/main/java/org/jabref/gui/errorconsole/LogEventViewModel.java
@@ -6,7 +6,7 @@
 import org.jabref.gui.IconTheme;
 import org.jabref.logic.util.OS;
 
-import org.apache.commons.lang3.exception.ExceptionUtils;
+import com.google.common.base.Throwables;
 import org.apache.logging.log4j.core.LogEvent;
 
 public class LogEventViewModel {
@@ -46,7 +46,7 @@ public IconTheme.JabRefIcon getIcon() {
     }
 
     public Optional<String> getStackTrace() {
-        return Optional.ofNullable(logEvent.getMessage().getThrowable()).map(ExceptionUtils::getStackTrace);
+        return Optional.ofNullable(logEvent.getMessage().getThrowable()).map(Throwables::getStackTraceAsString);
     }
 
     public String getDetailedText() {
diff --git a/src/main/java/org/jabref/gui/groups/GroupNodeViewModel.java b/src/main/java/org/jabref/gui/groups/GroupNodeViewModel.java
index 5a8069b08da..e53a54f5099 100644
--- a/src/main/java/org/jabref/gui/groups/GroupNodeViewModel.java
+++ b/src/main/java/org/jabref/gui/groups/GroupNodeViewModel.java
@@ -33,9 +33,9 @@
 import org.jabref.model.groups.GroupTreeNode;
 import org.jabref.model.strings.StringUtil;
 
+import com.google.common.base.Enums;
 import com.google.common.eventbus.Subscribe;
 import de.jensd.fx.glyphs.materialdesignicons.MaterialDesignIcon;
-import org.apache.commons.lang3.EnumUtils;
 import org.fxmisc.easybind.EasyBind;
 
 public class GroupNodeViewModel {
@@ -187,7 +187,7 @@ public MaterialDesignIcon getIcon() {
     }
 
     private Optional<MaterialDesignIcon> parseIcon(String iconCode) {
-        return Optional.ofNullable(EnumUtils.getEnum(MaterialDesignIcon.class, iconCode.toUpperCase(Locale.ENGLISH)));
+        return Enums.getIfPresent(MaterialDesignIcon.class, iconCode.toUpperCase(Locale.ENGLISH)).toJavaUtil();
     }
 
     public ObservableList<GroupNodeViewModel> getChildren() {
diff --git a/src/main/java/org/jabref/gui/preftabs/PreviewPrefsTab.java b/src/main/java/org/jabref/gui/preftabs/PreviewPrefsTab.java
index 7cc66841421..b1ef3193fe0 100644
--- a/src/main/java/org/jabref/gui/preftabs/PreviewPrefsTab.java
+++ b/src/main/java/org/jabref/gui/preftabs/PreviewPrefsTab.java
@@ -27,9 +27,9 @@
 import org.jabref.logic.util.TestEntry;
 import org.jabref.preferences.PreviewPreferences;
 
+import com.google.common.primitives.Ints;
 import com.jgoodies.forms.builder.FormBuilder;
 import com.jgoodies.forms.factories.Paddings;
-import org.apache.commons.lang3.ArrayUtils;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
@@ -95,7 +95,7 @@ private void setupLogic() {
                 chosenModel.add(newIndex, chosenModel.remove(oldIndex));
                 newSelectedIndices.add(newIndex);
             }
-            chosen.setSelectedIndices(ArrayUtils.toPrimitive(newSelectedIndices.toArray(new Integer[newSelectedIndices.size()])));
+            chosen.setSelectedIndices(Ints.toArray(newSelectedIndices));
         });
 
         btnDown.addActionListener(event -> {
@@ -108,7 +108,7 @@ private void setupLogic() {
                 chosenModel.add(newIndex, chosenModel.remove(oldIndex));
                 newSelectedIndices.add(newIndex);
             }
-            chosen.setSelectedIndices(ArrayUtils.toPrimitive(newSelectedIndices.toArray(new Integer[newSelectedIndices.size()])));
+            chosen.setSelectedIndices(Ints.toArray(newSelectedIndices));
         });
 
         btnDefault.addActionListener(event -> layout.setText(Globals.prefs.getPreviewPreferences()
diff --git a/src/main/java/org/jabref/logic/formatter/bibtexfields/HtmlToUnicodeFormatter.java b/src/main/java/org/jabref/logic/formatter/bibtexfields/HtmlToUnicodeFormatter.java
index 7ef2e651b24..c598966e7c9 100644
--- a/src/main/java/org/jabref/logic/formatter/bibtexfields/HtmlToUnicodeFormatter.java
+++ b/src/main/java/org/jabref/logic/formatter/bibtexfields/HtmlToUnicodeFormatter.java
@@ -1,11 +1,13 @@
 package org.jabref.logic.formatter.bibtexfields;
 
+import org.jabref.architecture.ApacheCommonsLang3Allowed;
 import org.jabref.logic.l10n.Localization;
 import org.jabref.logic.layout.LayoutFormatter;
 import org.jabref.model.cleanup.Formatter;
 
 import org.apache.commons.lang3.StringEscapeUtils;
 
+@ApacheCommonsLang3Allowed("There is no equivalent in Google's Guava")
 public class HtmlToUnicodeFormatter implements LayoutFormatter, Formatter {
 
     @Override
diff --git a/src/main/java/org/jabref/logic/integrity/IntegrityMessage.java b/src/main/java/org/jabref/logic/integrity/IntegrityMessage.java
index f1d6735c332..c04a63f87fa 100644
--- a/src/main/java/org/jabref/logic/integrity/IntegrityMessage.java
+++ b/src/main/java/org/jabref/logic/integrity/IntegrityMessage.java
@@ -4,11 +4,10 @@
 
 import org.jabref.model.entry.BibEntry;
 
-import org.apache.commons.lang3.builder.EqualsBuilder;
-
 public final class IntegrityMessage implements Cloneable {
 
     private final BibEntry entry;
+
     private final String fieldName;
     private final String message;
 
@@ -41,22 +40,13 @@ public Object clone() {
     }
 
     @Override
-    public boolean equals(Object obj) {
-        if (obj == null) {
-            return false;
-        }
-        if (obj == this) {
-            return true;
-        }
-        if (obj.getClass() != getClass()) {
-            return false;
-        }
-        IntegrityMessage that = (IntegrityMessage) obj;
-        return new EqualsBuilder()
-                .append(entry, that.entry)
-                .append(fieldName, that.fieldName)
-                .append(message, that.message)
-                .isEquals();
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        IntegrityMessage that = (IntegrityMessage) o;
+        return Objects.equals(entry, that.entry) &&
+                Objects.equals(fieldName, that.fieldName) &&
+                Objects.equals(message, that.message);
     }
 
     @Override
diff --git a/src/main/java/org/jabref/model/strings/StringUtil.java b/src/main/java/org/jabref/model/strings/StringUtil.java
index 9f52af3fffb..d9cf81c2172 100644
--- a/src/main/java/org/jabref/model/strings/StringUtil.java
+++ b/src/main/java/org/jabref/model/strings/StringUtil.java
@@ -10,9 +10,12 @@
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import org.jabref.architecture.ApacheCommonsLang3Allowed;
+
 import com.google.common.base.CharMatcher;
 import org.apache.commons.lang3.StringUtils;
 
+@ApacheCommonsLang3Allowed("There is no equivalent in Google's Guava")
 public class StringUtil {
 
     // Non-letters which are used to denote accents in LaTeX-commands, e.g., in {\"{a}}
@@ -624,7 +627,11 @@ public static boolean isBlank(Optional<String> string) {
         return !isNotBlank(string);
     }
 
+    /**
+     * Checks if a CharSequence is not empty (""), not null and not whitespace only.
+     */
     public static boolean isNotBlank(String string) {
+        // No Guava equivalent existing
         return StringUtils.isNotBlank(string);
     }
 
@@ -678,6 +685,7 @@ public static String unquote(String toUnquote, char quoteChar) {
         return result.toString();
     }
 
+    @ApacheCommonsLang3Allowed("No Guava equivalent existing - see https://stackoverflow.com/q/3322152/873282 for a list of other implementations")
     public static String stripAccents(String searchQuery) {
         return StringUtils.stripAccents(searchQuery);
     }
@@ -707,6 +715,7 @@ public static List<String> getStringAsWords(String text) {
         return Arrays.asList(text.split("[\\s,;]+"));
     }
 
+    @ApacheCommonsLang3Allowed("No direct Guava equivalent existing - see https://stackoverflow.com/q/16560635/873282")
     public static boolean containsIgnoreCase(String text, String searchString) {
         return StringUtils.containsIgnoreCase(text, searchString);
     }
diff --git a/src/test/java/org/jabref/CodeStyleTests.java b/src/test/java/org/jabref/CodeStyleTests.java
index 7a1cef60a65..ec6a5641437 100644
--- a/src/test/java/org/jabref/CodeStyleTests.java
+++ b/src/test/java/org/jabref/CodeStyleTests.java
@@ -19,6 +19,6 @@ public void StringUtilClassIsSmall() throws Exception {
 
         Assert.assertTrue("StringUtil increased in size. "
                 + "We try to keep this class as small as possible. "
-                + "Thus think twice if you add something to StringUtil.", lineCount <= 715);
+                + "Thus think twice if you add something to StringUtil.", lineCount <= 722);
     }
 }
diff --git a/src/test/java/org/jabref/MainArchitectureTests.java b/src/test/java/org/jabref/architecture/MainArchitectureTests.java
similarity index 99%
rename from src/test/java/org/jabref/MainArchitectureTests.java
rename to src/test/java/org/jabref/architecture/MainArchitectureTests.java
index ea72ed250ab..7a98c05122c 100644
--- a/src/test/java/org/jabref/MainArchitectureTests.java
+++ b/src/test/java/org/jabref/architecture/MainArchitectureTests.java
@@ -1,4 +1,4 @@
-package org.jabref;
+package org.jabref.architecture;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
diff --git a/src/test/java/org/jabref/architecture/MainArchitectureTestsWithArchUnit.java b/src/test/java/org/jabref/architecture/MainArchitectureTestsWithArchUnit.java
new file mode 100644
index 00000000000..6120da6b808
--- /dev/null
+++ b/src/test/java/org/jabref/architecture/MainArchitectureTestsWithArchUnit.java
@@ -0,0 +1,20 @@
+package org.jabref.architecture;
+
+import com.tngtech.archunit.junit.AnalyzeClasses;
+import com.tngtech.archunit.junit.ArchTest;
+import com.tngtech.archunit.junit.ArchUnitRunner;
+import com.tngtech.archunit.lang.ArchRule;
+import org.junit.runner.RunWith;
+
+import static com.tngtech.archunit.lang.syntax.ArchRuleDefinition.noClasses;
+
+@RunWith(ArchUnitRunner.class)
+@AnalyzeClasses(packages = "org.jabref")
+public class MainArchitectureTestsWithArchUnit {
+
+    @ArchTest
+    public static final ArchRule doNotUseApacheCommonsLang3 =
+            noClasses().that().areNotAnnotatedWith(ApacheCommonsLang3Allowed.class)
+            .should().accessClassesThat().resideInAPackage("org.apache.commons.lang3");
+
+}
diff --git a/src/test/java/org/jabref/TestArchitectureTests.java b/src/test/java/org/jabref/architecture/TestArchitectureTests.java
similarity index 95%
rename from src/test/java/org/jabref/TestArchitectureTests.java
rename to src/test/java/org/jabref/architecture/TestArchitectureTests.java
index 955d731f8c8..b1c0dc618a5 100644
--- a/src/test/java/org/jabref/TestArchitectureTests.java
+++ b/src/test/java/org/jabref/architecture/TestArchitectureTests.java
@@ -1,4 +1,4 @@
-package org.jabref;
+package org.jabref.architecture;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
@@ -17,7 +17,7 @@
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
 
-import static org.jabref.MainArchitectureTests.CLASS_ORG_JABREF_GLOBALS;
+import static org.jabref.architecture.MainArchitectureTests.CLASS_ORG_JABREF_GLOBALS;
 
 @RunWith(Parameterized.class)
 public class TestArchitectureTests {