A method for executing tasks of a real-time application on a multitasking computer, each task (A, B) comprising at least one processing operation (Ti), characterised in that the method comprises steps of: defining time windows each associated with the execution of a processing operation of a task of the application, allocating to each processing operation having a time window, a time quota (Qi) and a time margin (Mi), the time allocated to the processing operation by the time quota and the time margin being shorter than the duration of the time window associated with the processing operation, during the execution of the application by the multitasking computer, activating each processing operation at the start of the time window associated with the processing operation, on expiry of the time quota of one of the processing operations, activating an error mode for said processing operation if the execution of said processing operation has not been completed, and if the error mode is active for one of the processing operations, executing an error handling procedure for the processing operation in error mode during the remaining time allocated to the processing operation by the time quota and the time margin, and continuing the execution of the processing operation (Ti) the execution of which has not been completed on expiry of the time quota (Qi) allocated to the processing operation, while monitoring the expiry of the time margin (Mi) allocated to the processing operation, and on expiry of the time margin allocated to the processing operation, if the execution of the processing operation has not been completed, ending the execution of the processing operation and executing a time quota overrun error handling operation. defining time windows each associated with the execution of a processing operation of a task of the application, allocating to each processing operation having a time window, a time quota (Qi) and a time margin (Mi), the time allocated to the processing operation by the time quota and the time margin being shorter than the duration of the time window associated with the processing operation, during the execution of the application by the multitasking computer, activating each processing operation at the start of the time window associated with the processing operation, on expiry of the time quota of one of the processing operations, activating an error mode for said processing operation if the execution of said processing operation has not been completed, and if the error mode is active for one of the processing operations, executing an error handling procedure for the processing operation in error mode during the remaining time allocated to the processing operation by the time quota and the time margin, and continuing the execution of the processing operation (Ti) the execution of which has not been completed on expiry of the time quota (Qi) allocated to the processing operation, while monitoring the expiry of the time margin (Mi) allocated to the processing operation, and on expiry of the time margin allocated to the processing operation, if the execution of the processing operation has not been completed, ending the execution of the processing operation and executing a time quota overrun error handling operation.