In the published article the process of interaction of several related economic systems, which, on the one hand, compete with each other for fixed assets, the necessary human capital and natural resources is examined. On the other hand, they complement and develop each other and form a single complex within which joint goods are produced, goods, services and financial resources are exchanged, etc. An economic-mathematical model of the dynamics of development and interaction of related economic systems is proposed, taking into account both their competition for resources and their cooperation in the production of joint benefits. This model is a system of non-linear differential equations, which are used to calculate indicators of the dynamics of development of related systems of the economy. The values of these indicators depend on the ratio of investment investments in the production of economic systems and their depreciation deductions for the restoration of resources and costs. The peculiarity of the presented model is that the production function of each economic system containing as arguments not only its own production factors, but also the resources of all other considered related economic entities. It is shown that by controlling the choice of the rates of accumulation of internal investments of economic systems, it is possible to obtain various options for their interaction. With a certain choice of accumulation rates, economic systems can operate independently of each other. Under other norms, some systems of the economy become independent and backbone, while the rest of the systems are subsidized.