This article focuses on understanding the methods of managing the outsourcing relationship in Moroccan public establishments during the post-covid period in particular. It is interested in identifying and analyzing all the factors influencing the management of this relationship in the public sphere. First, we are interested in the development of the conceptual framework dealing with the management of the outsourcing relationship between public institutions and their external service providers. Subsequently and on the basis of our qualitative empirical study, we identify the factors influencing this inter-organizational relationship, particularly in the Moroccan public context. In the end, we present the results obtained from our study of multiple cases, carried out with Moroccan public establishments with commercial and industrial activity. Compared to the methods of managing the outsourcing relationship between a public order giver and an external service provider, this research highlights endogenous factors such as: (resource differential, need for flexibility, proximity to the core business and finally the cost and complexity of control) and other exogenous factors such as: (pressures from the institutional environment, substitutability of service providers) as determinants of the design of the choice of management methods, namely: (management by the control, relationship management).