A command execution controlling apparatus, comprising: an execution command receiver which receives execution commands from an external command transmitting entity; an execution command storage unit which stores the received execution commands, wherein a predetermined upper-limit number of execution commands to be stored is set; an execution command issuing unit which retrieves the execution commands stored in said storage unit and issues them to a command execution entity according to an issuance order determined among the execution commands; an adjustment command receiver which receives an adjustment command, transmitted from the command transmitting entity, to adjust the issuance order of the execution commands; and an adjustment command storage unit which stores the adjustment command received by said adjustment command receiver, wherein adjustement of the order of issuing execution commands is performed by issuing an execution command received after the reception of the adjustment command, on the condition that the issuance of execution commands received prior to the reception of the adjustment command has been completed, and characterized in that a storage area for storing the execution commands to be stored in said execution command storage unit and a storage area for storing the adjustment command to be stored in said adjustment command storage unit are separately secured, a plurality of pairs of said execution command storage unit and said adjustment command storage unit are provided in association with a plurality of respective command execution entities, the adjustment command contains storage destination specifying information to specify any of a plurality of adjustment command storage units, by referring to the storage destination specifying information in the adjustment command, said adjustment command receiver selects an adjustment command storage unit which is to store the adjustment command, and when the adjustment command is stored, said execution command issuing unit performs issuance order adjustment processing to adjust the order of issuing commands retrieved from the execution command storage unit which is paired with the adjustment command storage unit that stores said adjustment command. an execution command receiver which receives execution commands from an external command transmitting entity; an execution command storage unit which stores the received execution commands, wherein a predetermined upper-limit number of execution commands to be stored is set; an execution command issuing unit which retrieves the execution commands stored in said storage unit and issues them to a command execution entity according to an issuance order determined among the execution commands; an adjustment command receiver which receives an adjustment command, transmitted from the command transmitting entity, to adjust the issuance order of the execution commands; and an adjustment command storage unit which stores the adjustment command received by said adjustment command receiver, wherein adjustement of the order of issuing execution commands is performed by issuing an execution command received after the reception of the adjustment command, on the condition that the issuance of execution commands received prior to the reception of the adjustment command has been completed, and characterized in that a storage area for storing the execution commands to be stored in said execution command storage unit and a storage area for storing the adjustment command to be stored in said adjustment command storage unit are separately secured, a plurality of pairs of said execution command storage unit and said adjustment command storage unit are provided in association with a plurality of respective command execution entities, the adjustment command contains storage destination specifying information to specify any of a plurality of adjustment command storage units, by referring to the storage destination specifying information in the adjustment command, said adjustment command receiver selects an adjustment command storage unit which is to store the adjustment command, and when the adjustment command is stored, said execution command issuing unit performs issuance order adjustment processing to adjust the order of issuing commands retrieved from the execution command storage unit which is paired with the adjustment command storage unit that stores said adjustment command.