Considering that it will not be easy to make an improvement in production factors without any cost, the most critical field for businesses to minimize costs is logistics and supply chain structures. Likewise, the most important production factor that provides competitive advantage for businesses is human resources, also known as intellectual capital. In this context, it is vital to assign the right personnel to the right job. In case of selection and assignment of personnel based on merit, efficient use of business resources will be ensured and the final efficiency of the business will be positively affected, thereby paving the way for competitive advantage. Today, a wide variety of applications and tests are carried out for personnel selection. These methods, most of which are based on intuitive and personal judgments, can sometimes lead to wrong selection. It is obvious that short job interviews and/or job trial periods will not be enough to get to know the individual with his/her personality. In this context, the importance of multi-criteria decision-making techniques, which are frequently used in choosing the most suitable one among different personnel alternatives, is mentioned in the study. Multi-criteria decision-making techniques are an important aid for decision makers in personnel selection, as in many different areas. Although a significant part of the methods still require intuitive approaches such as expert opinion, the PSI method used in the study allows for the impartial evaluation of the alternatives and to reach conclusions on the numerical values they have, with the application stages in a completely rational way. In the study, a personnel selection decision to be made under the influence of many criteria with different importance levels is solved with the PSI method, which is one of the multi-criteria decision-making techniques and has been frequently used in different fields recently, and the results are shared. In this context, one of them is cost-oriented (C1-Negative Personality Traits) and the others are benefit-oriented (C2-Foreign Language Grade, C3-Year of Experience, C4-Team Work Skill, C5-Empathy Ability, C6-Problem Solving Ability and C7-Appearance) considering a total of 7 criteria, the most suitable one among 6 candidates was determined.