A Markov chain-based scheduling operations hierarchical risk assessment method is proposed. The characteristics of two major influencing factors of scheduling operations

which are operation result of each step and facility failures

are analyzed and decoupled with the hierarchical method. In the external layer

Markov chain is used to simulate the evaluation of system topologies during scheduling operations and achieve their probability distributions. In the internal layer

the state enumeration method is used to calculate risk indices of each system topology. By calculating the weighted sum of all system topologies according to the probability distribution of each operation step

final indices of scheduling operations will be obtained. The proposed approach is able to assess risk indices of scheduling operation efficiently and accurately

and provide index support for operators to optimize scheduling operations. Case studies based on a modified IEEE reliability test system and a practical system demonstrate the validity

effectiveness and utility value of the proposed approach. This work is supported by National Natural Science Foundation of China (No. 51277128

No. 51377118

No. 51337005) and State Grid Corporation of China (No. DZB17201200260).