Generally, the wind power division has an after-sales service department, which is responsible for the installation infrastructure and trial operation of the wind turbine in the early stage. In general, after the trial operation, the wind turbines will be delivered to Party A's electric field for management and maintenance by the wind farm. But now, in order to improve the processing speed and quality of after-sales service, the general wind turbine main engine factory will station one or several engineers in a wind farm to take charge of long-term maintenance, that is to say, it will stay in the wind farm. This is the waiting service engineer, and the main engine factory is CSR Group.