A Preliminary, Normative Theory of Cockpit Task Management
A Preliminary, Normative Theory of Cockpit Task Management |
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| Synopsis: | This page presents a preliminary, normative theory of Cockpit Task Management (CTM): how CTM should be performed. | ||
| Keywords: | cockpit task management, definition | ||
| Author: | |||
| Ken Funk | <funkk@engr.orst.edu> | Department of Industrial and Manufacturing Engineering, Oregon State University, Corvallis, Oregon, USA | |
| Last Update: | 19 July 1999 | This is a Work in Progress and its contents are subject to continual revision. | |
The process by which the flight crew manages an agenda of cockpit tasks is called Cockpit Task Management (CTM). CTM is a procedure that is executed by the flight crew as follows:
This procedure and the following explanation comprise a preliminary normative theory of CTM that seeks to identify the task management functions which should be performed by the flight crew. Together they represent an initial formalization of the functions the flight crew should use to manage their activities successfully.
Given a hierarchy of goals to accomplish in a mission, the first CTM step for the flight crew is to create the initial agenda. This agenda consists of a task to achieve each goal. An initial event must be defined for each goal/task pair.
Once the agenda has been created, a process of agenda management begins and continues until the mission goal is achieved or unachievable. In the latter case, the process should end only after the aircraft and its subsystems reach some safe state.
The flight crew must assess the current situation. The states of all relevant aircraft systems and subsystems must be considered to determine if significant events have occurred.
When initial events occur, the flight crew must activate tasks that are contingent upon those events. This means that these tasks enter the active and should become active in progress as soon as resources are available.
The flight crew must assess the status of active tasks to determine if satisfactory progress is being made toward achieving the tasks' goals. Not only must the current status of each task be assessed, but if the task's goal is not yet achieved, the status of the task must be projected into the future to determine the likelihood that the goal will be achieved. A task's status may be declared satisfactory if its goal is achieved or is likely to be achieved, marginal if achievement of its goal is uncertain, or unsatisfactory if the goal is violated or is unlikely to be achieved without corrective action.
Based on this assessment, the flight crew should terminate tasks with achieved or unachievable goals. Tasks whose goals become irrelevant due to changing circumstances should also be terminated. Termination removes tasks from competition for resources.
For the remaining active tasks, the flight crew should assess task resource requirements to determine what resources are required to complete them. A newly activated task might be started with minimal resources, but a task of marginal or unsatisfactory status might require additional resources to achieve its goal.
The flight crew should prioritize the active tasks. Factors that can influence task priority include the following:
1. The importance and urgency of the task's goal.
2. The importance and urgency of other active tasks' goals.
3. The current and projected status of the task.
4. The current and projected statuses of other active tasks.
Prioritization can be defined as a pairwise comparison of tasks based on these factors and others, that results in an ordering of active tasks.
As a result of the previous steps, the flight crew must then allocate resources to tasks in order of priority. This is an assignment of resources to tasks, with preference given to high-priority tasks, so that the tasks may be executed. The flight crew should initiate newly activated high priority tasks to make them active in progress. They should interrupt low-priority tasks that are active in progress when high-priority tasks requiring the same resources become active. When the high priority tasks finish and resources become available again, the flight crew should resume interrupted tasks, returning them to the active in progress state. These steps result in a set of tasks in the process of execution.
This process causes changes in the set of pending and active tasks and changes in task status and priority. The flight crew should update the agenda to reflect these changes and repeat the process.
Listed below, most recent first, are changes made to this page since its creation.