With the advent of smart grids and continuous restructuring of power industry

modern power systems have gradually evolved into complex cyber-physical systems which are characterized with high renewable energy penetrations

distributed facilities

advanced metering and communication technologies

as well as ever-increasing customer awareness. In an electricity retail market

these new development trends pose significant challenges for electricity retailers and call for innovative decision-making methods. Meanwhile

China has begun to establish competitive electricity retail markets in the new round of in-depth reforms for the power industry. In order to provide a beneficial reference for constructing complete competitive electricity retail markets in China

and also to help researchers and engineers have a better overview of the state-of-the-art on the business process and decision-making schemes of electricity retailers

this paper first introduces the development history of electricity retail markets around the world. Then

it elaborates the business process of electricity retailers in Australia and Finland

and surveys the latest progress on decision-making of electricity retailers

including retail energy forecasting

energy procurement strategies and retail pricing strategies for electricity retailers

and risk management in retail markets. Finally

some critical and open issues in this field are discussed.