public String remove(){   
   super.getInstance().getProject().getQuantExperiment().remove(getInstance());
   return super.remove();
}

@Entity(name = "Experiment")
public class Experiment implements Equals, HashCode, ToString
{
   
   protected List<ExperimentHistoryRecords> ExperimentHistoryRecords;
   protected Project project;

   @OneToMany(cascade = {CascadeType.ALL}, fetch = FetchType.LAZY, mappedBy="Experiment")
   public List<ExperimentHistoryRecords> getExperimentHistoryRecords() {
        if (ExperimentHistoryRecords == null) {
            ExperimentHistoryRecords = new ArrayList<ExperimentHistoryRecords>();
        }
        return this.ExperimentHistoryRecords;
   }

   public void setExperimentHistoryRecords(List<ExperimentHistoryRecords> ExperimentHistoryRecords) {
       for(ExperimentHistoryRecords qehr : ExperimentHistoryRecords){
          qehr.setQuantExperiment(this);
       }
        this.ExperimentHistoryRecords = ExperimentHistoryRecords;
    }

   @ManyToOne(fetch = FetchType.LAZY, optional=false)
   public Project getProject() {
      return project;
   }

   public void setProject(Project project) {
      this.project = project;
   }
   ....
}

@Entity(name = "ExperimentHistoryRecords")
public class ExperimentHistoryRecords implements Equals, HashCode, ToString
{
   protected Experiment Experiment;
   protected Project project;

   @ManyToOne(fetch = FetchType.LAZY, optional=false)
    public Experiment getQuantExperiment() {
        return Experiment;
    }

   public void setQuantExperiment(Experiment value) {
        this.Experiment = value;
    }

   @ManyToOne(fetch = FetchType.LAZY, optional=false)
    public Project getProject() {
        return project;
    }

   public void setProject(Project value) {
        this.project = value;
    }

public class ExperimentHome extends EntityHome<Experiment> {
....
public String remove(){

   super.getInstance().getProject().getExperiment().remove(getInstance());
   return super.remove();
}

public class EntityHome<E> extends Home<EntityManager, E>{
   .....
@Transactional
   public String remove()
   {
      getEntityManager().remove( getInstance() );
      getEntityManager().flush();
      deletedMessage();
      raiseAfterTransactionSuccessEvent();
      return "removed";
   }
}

b]QuantExperimentHome.java[/b
public String remove(){
   ////JUST TO CHECK////
List<QuantExperimentHistoryRecords> qeHr= getInstance().getQuantExperimentHistoryRecords();
int xs=qeHr.size();
for(int i=0;i<xs;i++){
  QuantExperimentHistoryRecords qeg=qeHr.get(i);
  //entityManager.remove(qeg); // TRIED THIS ALSO
  System.out.println("CHECK, QuantExperimentHistoryRecords HJID is = "+qeg.getHjid()+", and QuantExperiment HJID is : "+qeg.getQuantExperiment().getHjid());
}
////END CHECK////

super.getInstance().getProject().getQuantExperiment().remove(getInstance());
return super.remove();
}

@Entity(name = "QuantExperiment")
public class QuantExperiment implements Equals, HashCode, ToString
{
protected List<QuantExperimentHistoryRecords> quantExperimentHistoryRecords;
protected Project project;

@OneToMany(cascade = {CascadeType.ALL},fetch = FetchType.LAZY, mappedBy="quantExperiment")
public List<QuantExperimentHistoryRecords> getQuantExperimentHistoryRecords() {
  if (quantExperimentHistoryRecords == null) {
   quantExperimentHistoryRecords = new ArrayList<QuantExperimentHistoryRecords>();
  }
  return this.quantExperimentHistoryRecords;
}

@ManyToOne(fetch = FetchType.LAZY, optional=false)
public Project getProject() {
  return project;
}
}

@Entity(name = "QuantExperimentHistoryRecords")
public class QuantExperimentHistoryRecords implements Equals, HashCode, ToString {
   protected Project project;
protected QuantExperiment quantExperiment;

@ManyToOne(fetch = FetchType.LAZY, optional=false)
public QuantExperiment getQuantExperiment() {
  return quantExperiment;
}

@ManyToOne(fetch = FetchType.LAZY, optional=false)
public Project getProject() {
  return project;
}
}

@Entity(name = "Project")
public class Project implements Equals, HashCode, ToString
{
protected List<QuantExperiment> quantExperiment;
protected List<QuantExperimentHistoryRecords> quantExperimentHistoryRecords;

@OneToMany(cascade = {CascadeType.ALL},fetch=FetchType.LAZY, mappedBy="project")
    public List<QuantExperiment> getQuantExperiment() {
        if (quantExperiment == null) {
            quantExperiment = new ArrayList<QuantExperiment>();
        }
     return this.quantExperiment;
    }

@OneToMany(cascade = {CascadeType.ALL}, fetch = FetchType.LAZY, mappedBy="project")
    public List<QuantExperimentHistoryRecords> getQuantExperimentHistoryRecords() {
        if (quantExperimentHistoryRecords == null) {
            quantExperimentHistoryRecords = new ArrayList<QuantExperimentHistoryRecords>();
        }
        return this.quantExperimentHistoryRecords;
    }
}