<p>Although dependent competing failure processes (DCFP) have been extensively studied, their impact on the reliability of performance sharing systems remains unexplored. To bridge this gap, this paper proposes a comprehensive reliability assessment method for such systems, incorporating the effects of DCFP, transmission losses, and cognitive uncertainty. DCFP involve two competing failure mechanisms: hard failures triggered by external shocks and soft failures resulting from continuous degradation. First, the hard failure process is modeled using a combination of cumulative and extreme shock models. The state probability function of individual component is derived by integrating the Finite Markov Chain Imbedding Approach (FMCIA) with phase-type (PH) distributions. Second, the soft failure process is characterized via a Gamma degradation process, and the corresponding soft failure function is obtained through numerical integration. By merging the state probability functions from both failure processes, the integrated state probability of a component subject to DCFP is obtained. Furthermore, for performance sharing systems, a recursive reliability model is developed that explicitly incorporates a transmission loss function. The overall system reliability is then evaluated using the belief universal generating function (BUGF) method, effectively handling uncertainty in performance and demand levels. Finally, the proposed approach is validated through a case study of a regional power distribution system, demonstrating its practical applicability and effectiveness.</p>