Abstract: The sudden occurrence of uncertainty-creating factors such as natural disasters and public social events may have an impact on supply (production). For example, in recent years, the supply (production) of products has often been affected by hurricanes and strikes. The occurrence of these emergencies means the original optimal plan or mode of operation can no longer be carried out smoothly, and the coordinated supply chain is no longer coordinated, thus causing large losses to enterprises. Therefore, it is of great practical significance to study how the coordinated supply chain system deals with emergencies.
In this paper, a three-level supply chain system consisting of a manufacturer, a distributor and a retailer is considered where the manufacturer's output is random. At the same time, it is assumed that retail price depends on random output. It is studied that how a revenue sharing contract deals with disruptions to output caused by emergencies.
The decentralized decision-making model and centralized decision-making model are analyzed in the case of no emergencies and construct a revenue sharing contract model (original revenue sharing contract) to coordinate the supply chain. Second, it is assumed that emergencies will lead to changes in the distribution of random output. The optimal adjustment strategy is put forward for production following emergencies, a revised revenue sharing contract model is established, and the original revenue sharing contract and the revised revenue sharing contract model are compared. Finally, the impact of emergencies on optimal production planning, pricing decisions, profit and the coordination of the supply chain are analyzed.
Through the analysis of theoretical and numerical examples, the following conclusions are drawn:(1) After the emergency, the optimal production input quantity for a supply chain is not necessarily related to the output scale but depends on the new expected output and the output volatility. (2) When the range of output disruption due to emergencies is small, the optimal production plan and wholesale price of supply chain remain unchanged, and the retail price changes small. However, the coordination of the supply chain under the original revenue sharing contract will be broken, and the revised revenue sharing contract can better withstand emergencies. (3) When emergencies lead to a large range of output disruption, the optimal production input quantity of the supply chain is negatively related to the expected output and output volatility, and the optimal retail price is also negatively related to the expected output, while the optimal retail price is positively related to output volatility. (4) When emergencies lead to a large range of output disruption, the optimal wholesale price for distributor and retailer is negatively related to expected output and first decreases and then increases with the increase in output volatility. (5) Following an emergency, whether under the original revenue sharing contract or a revised revenue sharing contract, the profit of the supply chain system increases with the increase of expected output but decreases with the increase of output volatility. This study provides a basic method to mitigate the impact of emergencies on product supply (production) and therefore enriches current theoretical knowledge of supply chain emergency management while also providing some theoretical guidance for supply chain managers regarding the handling of emergencies.

Key words: supply chain coordination, revenue sharing contract, output disruption