A data processing apparatus includes a request receiving unit that receives a request from a program that causes a device to perform a predetermined process; an emulating unit that emulates a process performed by the device in accordance with the request; an instruction receiving unit that receives an instruction to change a status of the emulating unit from a user; a status changing unit that causes the emulating unit to change the status in accordance with the instruction to change the status; and a storing processing unit that stores, in response to generation of the request or generation of the instruction to change, information indicating the request or information indicating the instruction to change in a first storing unit, wherein the emulating unit emulates the process performed by the device under a status changed by the status changing unit.