ПАТЕРН ПРОЄКТУВАННЯ ДЛЯ ЗАБЕЗПЕЧЕННЯ ФУНКЦІОНАЛЬНОЇ СТІЙКОСТІ В ПРОГРАМНИХ СИСТЕМАХ

Context. Modern software systems operate in dynamic and harsh environments where internal and external failures, unexpected disturbances, direct attacks, and resource constraints challenge the consistent provision of core functionalities. In these contexts, ensuring functional stability – where the quality of each system function remains within a predetermined stable range despite failures or environmental anomalies – is critical, especially for safety-critical and high-availability applications.Objective. The primary objective of this work is to develop and justify an enabling design pattern that provides the architectural backbone for achieving functional stability in software systems. The main focus is to provide a flexible solution that facilitates dynamic adaptation while maintaining robust system behavior.Method. We propose a novel pattern that combines the dynamic strategy selection capabilities with the loose coupling between components afforded by an event-driven approach. This enabling pattern decouples system components by enforcing communication solely through standardized event types and allows each module to select an appropriate adaptation strategy based on its current context. The described pattern was used to build a design of a real-life example that aims to implement stable object tracking functionality for autonomous quad-platforms. The proposed design was evaluated using design-level metrics alongside qualitative comparisons with existing adaptive approaches.Results. Our analysis shows that the enabling pattern achieves significant modularity and adaptability. Key object-oriented metrics indicate minimal interdependencies among modules and a clear separation of concerns. The design proposal demonstrates that the pattern supports dynamic behavior adjustment through flexible strategy selection and serves as an enabler for functional stability by providing a robust architectural backbone for software systems.Conclusions. The scientific novelty of this work is twofold: firstly, the novel pattern is obtained in our study, providing dynamic adaptation through context-aware strategy selection; secondly, functional stability received further development in the area ofsoftware architecture. The proposed pattern offers a robust, scalable, and maintainable architectural solution, with significant practical implications for the design of adaptive, resilient software systems