diff --git a/.settings/edu.umd.cs.findbugs.core.prefs b/.settings/edu.umd.cs.findbugs.core.prefs
index f0adbfc1aa863f8bc6566990585a89c40e8a2d04..78d92c1e00c51ab8e63c31bb2f50f2036a80662a 100644
--- a/.settings/edu.umd.cs.findbugs.core.prefs
+++ b/.settings/edu.umd.cs.findbugs.core.prefs
@@ -1,5 +1,5 @@
 #FindBugs User Preferences
-#Tue Jul 14 13:07:22 CEST 2015
+#Tue Jul 14 14:13:17 CEST 2015
 detector_threshold=2
 effort=max
 excludefilter0=.fbExcludeFilterFile|true
diff --git a/pom.xml b/pom.xml
index 639aa96c44eff141ae25715ef90168b38efa860b..6ee38a6bf348b9abb41e1a9e20ec99b5478c7867 100644
--- a/pom.xml
+++ b/pom.xml
@@ -21,8 +21,13 @@
 
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<java.version>1.6</java.version>
 		<javadocOutputDir>apidocs</javadocOutputDir>
+		
+		<java.version>1.6</java.version>
+		<checkstyle.version>2.15</checkstyle.version>
+		<findbugs.version>3.0.1</findbugs.version>
+		<pmd.version>3.5</pmd.version>
+		<javadoc.version>2.10.3</javadoc.version>
 	</properties>
 
 	<distributionManagement>
@@ -184,7 +189,7 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-javadoc-plugin</artifactId>
-				<version>2.10.3</version>
+				<version>${javadoc.version}</version>
 				<executions>
 					<execution>
 						<id>attach-javadocs</id>
@@ -211,7 +216,7 @@
 			<!-- <plugin> -->
 			<!-- <groupId>org.apache.maven.plugins</groupId> -->
 			<!-- <artifactId>maven-checkstyle-plugin</artifactId> -->
-			<!-- <version>2.15</version> -->
+			<!-- <version>${checkstyle.version}</version> -->
 			<!-- <executions> -->
 			<!-- <execution> -->
 			<!-- <phase>test</phase> -->
@@ -235,7 +240,7 @@
 			<plugin>
 				<groupId>org.codehaus.mojo</groupId>
 				<artifactId>findbugs-maven-plugin</artifactId>
-				<version>3.0.1</version>
+				<version>${findbugs.version}</version>
 				<configuration>
 					<effort>Max</effort>
 					<threshold>Max</threshold>
@@ -269,7 +274,7 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-pmd-plugin</artifactId>
-				<version>3.5</version>
+				<version>${pmd.version}</version>
 				<dependencies>
 					<dependency>
 						<groupId>de.chw</groupId>
@@ -349,6 +354,12 @@
 					</execution>
 				</executions>
 			</plugin>
+			<!-- removes the recommendation message for javadoc-plugin -->
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-project-info-reports-plugin</artifactId>
+				<version>2.8</version>
+			</plugin>
 		</plugins>
 	</build>
 
@@ -375,19 +386,32 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-checkstyle-plugin</artifactId>
-				<version>2.15</version>
-				<reportSets>
-					<reportSet>
-						<reports>
-							<report>checkstyle</report>
-						</reports>
-					</reportSet>
-				</reportSets>
+				<version>${checkstyle.version}</version>
+				<!-- <reportSets> -->
+				<!-- <reportSet> -->
+				<!-- <reports> -->
+				<!-- <report>checkstyle</report> -->
+				<!-- </reports> -->
+				<!-- </reportSet> -->
+				<!-- </reportSets> -->
+			</plugin>
+			<!-- Findbugs -->
+			<plugin>
+				<groupId>org.codehaus.mojo</groupId>
+				<artifactId>findbugs-maven-plugin</artifactId>
+				<version>${findbugs.version}</version>
+			</plugin>
+			<!-- PMD -->
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-pmd-plugin</artifactId>
+				<version>${pmd.version}</version>
 			</plugin>
+			<!-- generate javadoc html files -->
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-javadoc-plugin</artifactId>
-				<version>2.10.3</version>
+				<version>${javadoc.version}</version>
 				<configuration>
 					<destDir>${javadocOutputDir}</destDir>
 				</configuration>