The Peruvian standard for the execution of contract works, requires that within the first month of execution, the contractor and supervisor hand in a technical file review report. However, it does not establish the procedures and/or actions that the entity, supervisor, or contractor carry out in the face of consultations, possible additions, or alerted risks, i.e., variations. In a similar situation, during the execution of the Calana potable water Treatment Plant in the city of Tacna, some additions were approved after 70 and 103 days of having identified their requirement in the technical file review reports, generating 107 days of extension of the deadline. Therefore, when reviewing possible improvements, it is proposed to modify Article 175, Requirements for the subscription of the contract work, to obtain timely communication between the contractor, supervisor, entity, and draftsman...