Until the middle of the 20th century, the development of social science theories was significantly influenced by the mechanical approach to research objects established in the exact and natural sciences, which is characterized by the following fundamental provisions:

• The relationships between individual elements of a system can be understood by isolating the interacting parts.
• There are predictable connections between these parts of the system.
• The results of the interaction of all elements of the system can be forecasted by analyzing and summarizing the interactions of individual elements (summing the parts).

However, this simplified understanding is being criticized, with an increasing emphasis on the dynamism and unpredictability of systems, structures, and processes. One of such approaches is complexity, which is currently applied in many fields of social science, management included.
The concept of complexity encompasses an evolving theoretical perspective. Complexity is defined as the scientific study of systems consisting of many interacting parts whose behavior cannot be explained by the individual elements, agents, or interactions among composing parts of the system (definition based on Thietart and Forgues). The complexity is greater for those systems that contain more qualitatively different dynamically interacting elements. The complexity approach can be useful in identifying and explaining systems or processes that lack stability and order. Social systems are always more complex than chemical, physical, and natural systems.
Classical management is based on positivist and rationalist assumptions, with stable functioning of systems ensured by centralized, hierarchical management focused on the implementation of various strategies and procedures aiming at efficiency and effectiveness. However, 21st-century postmodern society is complex, and constant change and uncertainty limit the scope of this classical approach. Strategies and practices based on purely rational arguments, stability, and predictability may not deliver the desired results.
The social phenomena we encounter in the field of management differ from the objects of study in the natural and exact sciences primarily in that they often arise and develop not only as the consequences of isolated causes, as, for example, we can see when analyzing chemical reactions or mechanical interactions between objects, where a certain stimulus produces a very clear and unambiguous response or result. Social contexts and circumstances are significantly more complex, as we encounter many new variables at a higher system level, such as inter-subjectivity, differences in the views and values of system elements and individuals (agents), top-down causality and mutual causality, where phenomena at a higher systemic level influence the elements of the system, which in turn shape the system, and the ability of the elements operating in the system – agents – to recognize, evaluate and influence the processes taking place in the system. Since social phenomena are very complex, and recently the complexity of such phenomena has been accelerating due to the impact of globalization in managerial systems, it is becoming very difficult to predict what policies, strategies, decisions, or interventions can produce the desired results that are effective and efficient in the context of organizational management.

The fundamental idea of complexity is that the analysis of various phenomena should focus not on individual elements of the system, but on the system itself as a whole, a network of various elements that interact with each other and determine the specific functioning of the system, which cannot be mechanically broken down into the behavior or actions of its constituent parts. On the other hand, the development of the system is inseparable from the interaction between its elements. The theory of complexity is dominated by the assumption that systems do not develop in a linear manner, as they are influenced by various feedback mechanisms and the principles of self-organization together with co-evolution.
Self-organization is a principle according to which social systems can organize themselves. Complex managerial systems cannot be fully understood or controlled, but certain approaches to dealing with them may be more useful and productive than others. It is sometimes paradoxically stated that complex managerial systems do not need to be managed, but rather interacted with in order to achieve the results required by all interested parties.
In managerial settings, self-organization arises from freedom of choice and the actions of people and organizations when they belong to a single system. Even when the system is affected by some strong external force, the elements of the system retain their freedom of choice and action, which can be used to achieve even greater adaptation. If a system is considered to be self-organizing and self-renewing, it obeys its internal dynamics and responds to the environment in a unique, specific way. Thus, the principles of the system’s operation become difficult to understand from an external perspective, and the system itself becomes resistant to external pressure, or at least the system’s response to such pressure is considered unique.
Managerial phenomena do not develop solely due to the influence of strong or external forces. Various social systems do not always obey rules, laws, and principles. Due to self-organization, such systems can develop along a trajectory that is difficult to predict and at an unknown speed.
The complexity perspective provides an opportunity to explain how independent elements interact to increase their resilience and chances of survival over time, when they are influenced by historical contexts, institutional forms, values, and other factors. It encourages understanding of the patterns and trends of interaction that arise in systems, rather than relying solely on isolated cause-and-effect relationships examined in isolation from their context. When assessing the functioning of complex systems, it is important to note that, due to the multitude of different interrelationships in a complex system, small effects under specific conditions can affect the entire system in unexpected ways, creating unpredictable results.
Complexity in organizational contexts refers to systems where interactions lead to emergent properties – behaviors or patterns that arise spontaneously from local interactions but are not directly controlled by any central authority. Predicting the behaviors of complex systems poses a significant challenge as such systems are adaptive, responsive, and interact with the environment through positive and negative feedback loops. This creates conditions whereby even very intense factors affecting the system may not have a significant impact, while relatively weak factors may have a disproportionately large impact and transform the system fundamentally (the best example here is E. Lorenzo’s “butterfly effect”). Thus, the impact on the system emanating from the center of the system (e.g., the CEOs, administration, board) may not be as significant and effective as the impact that can be caused by the interaction of individual elements of the system (e.g., the impact of a community or some other social group that has unexpectedly formed on social networks), which is generally less known and receives less attention when analyzing the system. The principles of self-organization of systems create the conditions for the emergence of mutually adaptive system elements, reinforce certain approaches in systems, and weaken others that hinder the newly emerging order and enable harmonious operation without greater external coordination.
In summary, it can be said that the provisions of complexity theory and methodology are becoming particularly important for understanding the contexts and processes of contemporary organizations, applying management methodologies and increasing their effectiveness, implementing systemic changes, and forming forecasting models. Such principles and factors related to the complexity approach as self-organization processes within organizations and teams, emergence, non-linearity and co-evolution, interdependence of agents (employees), decentralized, network-based structures, and shared leadership must be further explored in developing new management principles applicable to the contemporary complex environments.