Purpose of the study: The main criterion for choosing a model of the organization of the workflow by the employer is the cost-effectiveness and rationality of using labor resources. It is proved that the greatest efficiency of the working process can be achieved through the correct combination of full-time work with elements of part-time employment. It seems possible to enshrine such models of labor relations at the level of the legislation of the EU and individual countries by introducing appropriate amendments to labor legislation. Methodology: Hermeneutics, formal-logical and comparative law were used as the main methodological tools. In addition, the methods of systemic and structural analysis were used to identify the most successful mechanisms for the legal regulation of relations in the field of part-time employment. The study of the provisions of local regulations governing contractual relations was of particular success in achieving the research results. Main Findings: A conclusion was made that the transition to part-time employment can only take place within the labor relations between the employee and the employer. It is achieved through a combination of the means of contractual practices such as early notification of the other party (initiative) and negotiations aimed at resolving all issues related to changing working conditions. It has been found that most of the legislative rules are aimed at workers of medium-sized and large enterprises, certain categories of employees and duration of relations. Applications of this study: The study has an extended practical application. First of all, it can be used for developing the most effective modern mechanisms of part-time employment at the level of national legislation. The conclusions and the results of the study can also be used by companies in developing intra-corporate regulations. Novelty/Originality of this study: All types of effective HR management models based on part-time employment have been identified for the first time based on the transition from full-time to part-time work or vice versa. It was also proved for the first time with the help of scientific methodology, that the transition to part-time employment can only take place within the framework of labor relations between the employee and the employer.