The present article is an attempt to perceive the universal sustainability observable in an individual country or region, where the religious, political, social-demographic, economic, environmental, creative, technological and investment subsystems are revealed not only through the vitality of spiritual and material existence media, but rather through the signs of the development of these subsystems as self-assembled units through the erosion of their interaction. The problem of optimal allocation of investment resources among the separate sustainability’s subsystems was addressed by means of expert methods and techniques of portfolio methodology which will enable the achievement of the enshrined universal sustainability standards. A country-specific index composition of sustainability subsystems’ indices was chosen as the universal sustainability index for the specific country. The index in its dynamics is perceived as a random process. While projecting its state and evaluating its power, i.e.
, the impact of the subsystem efficiency in a particular moment, this power is measured by the level of the index and the reliability or guarantee of an appropriate level. To solve the problem of investment resources allocation, the idea of Markowitz Random Field was invoked in order to reach the maximum power of sustainability index while applying the technical solution—the so-called “GoldSim” system. Engineering is a methodology that aspires to reveal the core attributes of complex systems and instruments in order to manage the possibility to influence these properties for the systems. Experimental expert evaluation and case study is performed on Lithuanian data.