Facilitating debugging of business flows deployed on a production server. An aspect of the present invention processes some service requests (received from a client system) in a normal mode and some other service requests in a debug mode concurrently, all according to a business flow. According to another aspect, the debug mode supports a single step debug operation, in which each step corresponds to a single activity of the business flow. Accordingly, an administrator of the production server is enabled to better determine, the problems in the execution of business flows deployed on a production server at runtime.