An image processing apparatus comprising: a test data generator that generates test data instead of actual data entered for executing a workflow consisting of a plurality of unit works, if an instruction is given to test the workflow; a test process executor that executes a test process by processing the generated test data according to parameters for executing the unit works; a test process suspender that suspends the test process if a trouble happens during the test process; a notifier that notifies a user of a trouble if it happens during the test process; a parameter modifier that is capable of modifying the parameters if the test process is suspended due to the trouble; and a test process resuming portion that resumes the test process after the parameters are modified.