Res judicata in administrative courts procedure act

Res judicata is an ancient rule which is accepted by nearly all law systems. It has a great importance in supplying the judicial authority. After a conflict is brought before the court and the court gives the final judgment if there is no normal legal remedy left to be applied, the final judgment of the court becomes res judicata and it turns into a legal reality. As a result, the same parties with the same statement of facts cannot sue again on the same claim. Res judicata is an institution which is much related with the public order, is also a precondition, an objection and an evidence of litigation. The function of this principle is to ensure the economy of the courts, finalize the disputes definitely and maintain the peace of legal order. In the Code of Turkish Civil Procedure res judicata is regulated but there is no regulation in the Administrative Courts Procedure Act. However res judicata is already a principle of Administrative Justice and it is used in the decisions of the administrative courts. Nonetheless, res judicata in the decision of annulment has different characteristics than the other cases as it affects the ones who are non party to the former case.