In a shared-cache multi-core architecture one thread may interfere with a second thread if the second one tries to access the shared cache simultaneously.Consequently

this causes the eviction of the second thread instructions.To track this challenge

designers need to consider runtime inter-thread interference while analyzing WCET of a real-time application on multi-core architectures.This paper proposes an iterative approach for WCET estimation which considers the circular dependence between shared bus and the runtime inter-thread interference in shared cache.Our approach analyzes inter-thread interference in shared cache based on access timings

which combines static analysis and dynamic timing estimation.The iterative method presented can improve the tightness of WCET estimation by refining estimations of inter-thread interference.Our experiments demonstrate that the proposed approach can reasonably estimate inter-thread interference in shared caches and improve the tightness of WCET estimation by an average of 21% and 14%

compared with the estimations in literatures.