This paper introduces the appeal process into the legal framework and gives a brief overview of appeal proceedings in public procurement cases in theory and practice. Consequently, in practice, the appeal process usually ends with rejection of the appeal because of the unfoundedness of the appellate allegations and as a result of which months are lost in which the client stops the procedure and cannot contract until the State Commission for Control of the Procedure makes a decision, this paper focuses on the factual basis of the appeal process. Based on the above, at the heart of the subject analysis and reflection are the important issues of good definition of grievance allegations as a product of good practice and imperatives in the skills of filing grievances and proving that grievance allegations are discussed, giving critique and concrete suggestions of key methodology for setting elements of factual support. In this regard, examples of flat-rate appeal proceedings are presented, which stand out as the most common reasons for the loss of time in which the contracting authority could have completed the public procurement procedure in question. Also, from the client\u27s perspective, the importance of willingness to prove and justify annulment or selection is emphasized. The task of this paper is a thorough review of the most common problems during the appeal process in terms of the effective legal protection encountered by authorized representatives of contracting authorities and tenderers in the procedure, whose phases will try to justify the hypothesis that the demanding administrative complexity of the appeal process in terms of proving and refuting appellate allegations is one of the key reasons for the procedural issues of public procurement
