This book constitutes the proceedings of the 6th International Symposium on Dependable Software Engineering, SETTA 2020, held in Guangzhou, China, in November 2020.

The 10 full and 1 short paper included in this volume were carefully reviewed and selected from 20 submissions.

The Road Ahead for Supervisor Synthesis.- Reentrancy? Yes. Reentrancy bug? No.- Graph Transformation Systems: a Semantics Based on (Stochastic) Symmetric Nets.- Modelling and Implementation of Unmanned Aircraft Collision Avoidance.- Randomized Re nement Checking of Timed I/O Automata.- Computing Linear Arithmetic Representation for Reachability Relation of One-counter Automata.- Compiling FL^{res} on Finite Words.- Symbolic Model Checking with Sentential Decision Diagrams.- Probably Approximately Correct Interpolants Generation.- Symbolic Verification of MPI Programs with Non-deterministic Synchronizations.- Learning Safe Neural Network Controllers with Barrier Certificates.- Software Defect-proneness Prediction Based on Package Cohesion and Coupling Metrics.