Both contingency and temporary jobs are inherently project-oriented and represent a way of engaging human resources in organizations that have an “uncertain” budget, so those organizations strive to provide a greater level of flexibility in their human resource management. This pattern is prevalent among non-governmental organizations, engaging human resources through a contingency or temporal concept, depending on the needs of current projects. In addition to the non-governmental sector, the mentioned pattern is increasingly used also by private businesses and government institutions. The focus of this paper is to measure the impact of systemic transition management on the satisfaction and efficiency of the mentioned categories of employees. The paper recommends a series of steps and activities for maintaining employee satisfaction during and after the transition process, including effective communication, employee engagement, support and recognition of contributions, monitoring health impacts, and creating an inclusive environment. Research findings confirm the importance of both organizational and management supports in effective transition processes, underlying the need to improve opportunities for the professional development of employees. The research sample consists of one hundred (100) employees who come from randomly selected ten non-governmental organizations in Bosnia and Herzegovina. The results show consistency with theoretical frameworks and highlight key factors that need enhancement to improve the quality of transition processes and the overall satisfaction and efficiency of employees in the non-governmental sector.