diff --git a/lib/taskana-core/src/main/java/pro/taskana/JobService.java b/lib/taskana-core/src/main/java/pro/taskana/JobService.java
index 0620399a3..8b3bfed7c 100644
--- a/lib/taskana-core/src/main/java/pro/taskana/JobService.java
+++ b/lib/taskana-core/src/main/java/pro/taskana/JobService.java
@@ -9,6 +9,10 @@ public interface JobService {
 
     /**
      * Create a schedule a new job.
+     *
+     * @param job
+     *            {@link ScheduledJob} The job to be created.
+     * @return {@link ScheduledJob} The created job.
      */
     ScheduledJob createJob(ScheduledJob job);
 
diff --git a/lib/taskana-core/src/main/java/pro/taskana/Task.java b/lib/taskana-core/src/main/java/pro/taskana/Task.java
index edadb0ba2..e7f2100a5 100644
--- a/lib/taskana-core/src/main/java/pro/taskana/Task.java
+++ b/lib/taskana-core/src/main/java/pro/taskana/Task.java
@@ -159,7 +159,7 @@ public interface Task {
     /**
      * Returns the businessProcessId of a task.
      *
-     * @return businessProcessId
+     * @return businessProcessId Gets the business process id the task belongs to.
      */
     String getBusinessProcessId();
 
@@ -167,13 +167,14 @@ public interface Task {
      * Sets the external business process id.
      *
      * @param businessProcessId
+     *            Sets the business process id the task belongs to.
      */
     void setBusinessProcessId(String businessProcessId);
 
     /**
      * Returns the parentBusinessProcessId of a task.
      *
-     * @return parentBusinessProcessId
+     * @return parentBusinessProcessId Gets the parent business process id the task belongs to
      */
     String getParentBusinessProcessId();
 
@@ -181,6 +182,7 @@ public interface Task {
      * Sets the parent business process id to group associated processes.
      *
      * @param parentBusinessProcessId
+     *            Sets the parent business process id the task belongs to
      */
     void setParentBusinessProcessId(String parentBusinessProcessId);
 
diff --git a/lib/taskana-core/src/main/java/pro/taskana/jobs/TaskCleanupJob.java b/lib/taskana-core/src/main/java/pro/taskana/jobs/TaskCleanupJob.java
index 0688bbca6..2346dfea1 100644
--- a/lib/taskana-core/src/main/java/pro/taskana/jobs/TaskCleanupJob.java
+++ b/lib/taskana-core/src/main/java/pro/taskana/jobs/TaskCleanupJob.java
@@ -11,7 +11,11 @@ import java.util.stream.Collectors;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import pro.taskana.*;
+import pro.taskana.BaseQuery;
+import pro.taskana.BulkOperationResults;
+import pro.taskana.TaskSummary;
+import pro.taskana.TaskanaEngine;
+import pro.taskana.TimeInterval;
 import pro.taskana.exceptions.InvalidArgumentException;
 import pro.taskana.exceptions.TaskanaException;
 import pro.taskana.transaction.TaskanaTransactionProvider;
@@ -39,7 +43,8 @@ public class TaskCleanupJob extends AbstractTaskanaJob {
         runEvery = taskanaEngine.getConfiguration().getTaskCleanupJobRunEvery();
         minimumAge = taskanaEngine.getConfiguration().getTaskCleanupJobMinimumAge();
         batchSize = taskanaEngine.getConfiguration().getMaxNumberOfTaskUpdatesPerTransaction();
-        allCompletedSameParentBusiness = taskanaEngine.getConfiguration().isTaskCleanupJobAllCompletedSameParentBusiness();
+        allCompletedSameParentBusiness = taskanaEngine.getConfiguration()
+            .isTaskCleanupJobAllCompletedSameParentBusiness();
     }
 
     @Override
@@ -66,16 +71,20 @@ public class TaskCleanupJob extends AbstractTaskanaJob {
 
     private List<TaskSummary> getTasksCompletedBefore(Instant untilDate) {
         List<TaskSummary> taskList = taskanaEngineImpl.getTaskService()
-                .createTaskQuery()
-                .completedWithin(new TimeInterval(null, untilDate))
-                .orderByBusinessProcessId(asc)
-                .list();
+            .createTaskQuery()
+            .completedWithin(new TimeInterval(null, untilDate))
+            .orderByBusinessProcessId(asc)
+            .list();
 
         if (allCompletedSameParentBusiness) {
             Map<String, Long> numberParentTasksShouldHave = new HashMap<>();
             Map<String, Long> countParentTask = new HashMap<>();
             for (TaskSummary task : taskList) {
-                numberParentTasksShouldHave.put(task.getParentBusinessProcessId(), taskanaEngineImpl.getTaskService().createTaskQuery().parentBusinessProcessIdIn(task.getParentBusinessProcessId()).count());
+                numberParentTasksShouldHave.put(task.getParentBusinessProcessId(),
+                    taskanaEngineImpl.getTaskService()
+                        .createTaskQuery()
+                        .parentBusinessProcessIdIn(task.getParentBusinessProcessId())
+                        .count());
                 countParentTask.merge(task.getParentBusinessProcessId(), 1L, Long::sum);
             }
 
@@ -93,9 +102,9 @@ public class TaskCleanupJob extends AbstractTaskanaJob {
             String[] ids = new String[idsList.size()];
             ids = idsList.toArray(ids);
             taskList = taskanaEngineImpl.getTaskService()
-                    .createTaskQuery()
-                    .parentBusinessProcessIdIn(ids)
-                    .list();
+                .createTaskQuery()
+                .parentBusinessProcessIdIn(ids)
+                .list();
         }
 
         return taskList;
@@ -159,6 +168,7 @@ public class TaskCleanupJob extends AbstractTaskanaJob {
      * All scheduled cleanup jobs are cancelled/deleted and a new one is scheduled.
      *
      * @param taskanaEngine
+     *            the TASKANA engine.
      */
     public static void initializeSchedule(TaskanaEngine taskanaEngine) {
         TaskCleanupJob job = new TaskCleanupJob(taskanaEngine, null, null);
diff --git a/lib/taskana-core/src/main/java/pro/taskana/jobs/TaskanaJob.java b/lib/taskana-core/src/main/java/pro/taskana/jobs/TaskanaJob.java
index 156fd0b62..99f5c9fb8 100644
--- a/lib/taskana-core/src/main/java/pro/taskana/jobs/TaskanaJob.java
+++ b/lib/taskana-core/src/main/java/pro/taskana/jobs/TaskanaJob.java
@@ -9,6 +9,9 @@ public interface TaskanaJob {
 
     /**
      * Runs the TaskanaJob.
+     *
+     * @throws TaskanaException
+     *             if an exception occured during the run.
      */
     void run() throws TaskanaException;