diff --git a/petclinic-data/pom.xml b/petclinic-data/pom.xml
index edba5c1a9..de0f077ac 100644
--- a/petclinic-data/pom.xml
+++ b/petclinic-data/pom.xml
@@ -46,6 +46,14 @@
 </dependencies>
   <build>
     <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-javadoc-plugin</artifactId>
+        <configuration>
+          <goal>attach-javadocs</goal>
+          <javadocExecutable>${java.home}/bin/javadoc</javadocExecutable>
+        </configuration>
+      </plugin>
       <plugin>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-maven-plugin</artifactId>
@@ -62,4 +70,4 @@
       </plugin>
     </plugins>
   </build>
-</project>
+  </project>
diff --git a/petclinic-data/src/main/java/guru/springframework/springpetclinic/services/OwnerService.java b/petclinic-data/src/main/java/guru/springframework/springpetclinic/services/OwnerService.java
new file mode 100644
index 000000000..de9ee291b
--- /dev/null
+++ b/petclinic-data/src/main/java/guru/springframework/springpetclinic/services/OwnerService.java
@@ -0,0 +1,16 @@
+package guru.springframework.springpetclinic.services;
+
+import guru.springframework.springpetclinic.model.Owner;
+
+import java.util.Set;
+
+public interface OwnerService {
+
+	Owner findByLastName(String lastName);
+
+	Owner findById(Long id);
+
+	Owner save(Owner owner);
+
+	Set<Owner> findAll();
+}
diff --git a/petclinic-data/src/main/java/guru/springframework/springpetclinic/services/PetService.java b/petclinic-data/src/main/java/guru/springframework/springpetclinic/services/PetService.java
new file mode 100644
index 000000000..0a8bb8b52
--- /dev/null
+++ b/petclinic-data/src/main/java/guru/springframework/springpetclinic/services/PetService.java
@@ -0,0 +1,15 @@
+package guru.springframework.springpetclinic.services;
+
+import guru.springframework.springpetclinic.model.Owner;
+import guru.springframework.springpetclinic.model.Pet;
+
+import java.util.Set;
+
+public interface PetService {
+
+	Pet findById(Long id);
+
+	Pet save(Pet pet);
+
+	Set<Pet> findAll();
+}
diff --git a/petclinic-data/src/main/java/guru/springframework/springpetclinic/services/VetService.java b/petclinic-data/src/main/java/guru/springframework/springpetclinic/services/VetService.java
new file mode 100644
index 000000000..29a64c98c
--- /dev/null
+++ b/petclinic-data/src/main/java/guru/springframework/springpetclinic/services/VetService.java
@@ -0,0 +1,15 @@
+package guru.springframework.springpetclinic.services;
+
+import guru.springframework.springpetclinic.model.Pet;
+import guru.springframework.springpetclinic.model.Vet;
+
+import java.util.Set;
+
+public interface VetService {
+
+	Vet findById(Long id);
+
+	Vet save(Vet vet);
+
+	Set<Vet> findAll();
+}
diff --git a/petclinic-web/pom.xml b/petclinic-web/pom.xml
index f343d7290..8e2713e50 100644
--- a/petclinic-web/pom.xml
+++ b/petclinic-web/pom.xml
@@ -49,5 +49,16 @@
     <artifactId>spring-boot-starter-web</artifactId>
   </dependency>
 </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-javadoc-plugin</artifactId>
+        <configuration>
+          <javadocExecutable>${java.home}/bin/javadoc</javadocExecutable>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
 
 </project>
diff --git a/pom.xml b/pom.xml
index 338ec5051..0cce1d73f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -23,6 +23,13 @@
   </properties>
   <build>
     <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-javadoc-plugin</artifactId>
+        <configuration>
+          <javadocExecutable>${java.home}/bin/javadoc</javadocExecutable>
+        </configuration>
+       </plugin>
       <plugin>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-maven-plugin</artifactId>
@@ -32,6 +39,7 @@
         <artifactId>maven-release-plugin</artifactId>
         <configuration>
           <goals>install</goals>
+          <autoVersionSubmodules>true</autoVersionSubmodules>
         </configuration>
       </plugin>
     </plugins>
diff --git a/release.properties b/release.properties
deleted file mode 100644
index 0db5da55e..000000000
--- a/release.properties
+++ /dev/null
@@ -1,11 +0,0 @@
-#release configuration
-#Mon Nov 23 22:37:23 CET 2020
-projectVersionPolicyId=default
-scm.tagNameFormat=@{project.artifactId}-@{project.version}
-remoteTagging=true
-scm.commentPrefix=[maven-release-plugin] 
-pushChanges=true
-completedPhase=check-poms
-scm.url=scm\:git\:git@github.com\:marc-wagner/spring-petclinic.git
-exec.snapshotReleasePluginAllowed=false
-preparationGoals=clean verify