Man-machine system

A human-machine system (MMS) is the relationship observable or measurable processes that targeted in the performance, consciously controlled human activities specified or solve self-chosen tasks using machines occur in a system . MMSe therefore consist of at least two components: the acting person and the machine used. The complete description of MMSs also includes the description of the targeted activities in the form of task descriptions, objectives and partial steps.

Basics

If the activities required to complete the task are carried out step by step in several partial actions, it can be assumed that the result of an individual action achieved in each step is compared with the previously anticipated result and, if necessary, corrected in the following step. According to Sheridan (1987), a distinction has to be made between different forms of interactions between the people involved (surgeons) and tasks: direct control, manual control, monitoring control and fully automatic control.

Examples

Well-known examples of MMSs can be found in the management of vehicles of all kinds (bicycles, cars, ships, planes, etc.), where the interaction between man and technology is immediately clear. But also production facilities, operating theaters and research laboratories provide examples of MMS.

Explanations

Forms of interaction when performing targeted activities (after Sheridan, 1987)

Direct control

The processing of the task, i.e. the operator's influence on the process to be processed, takes place continuously and immediately. The task and its respective processing status can be perceived directly by the surgeon.

Manual control

A machine is inserted between the surgeon and the task. The process to be processed is affected indirectly by the operator operating control elements and thus setting the actuators (actuators) of the machine in motion, which act on the object. The task and its current processing status can be perceived either directly or via appropriate sensors and display devices (displays).

Supervisory control

The task is processed largely automatically, with control signals generated by suitable algorithms based on sensor information ensuring that the actuators act on the process to be processed. The surgeon is only indirectly involved; they monitor the processes by reading the displays and occasionally intervene in the event of a conflict or malfunction.

Fully automatic control

The task is completely processed by a machine without any involvement of an operator.

All of the forms of interaction mentioned, including fully automatic control, can be found, for example, when driving a car.

Task characterization

Because of the variety of possible uses of MMSs in production, movement or information processes (Johannsen, 1993), it is necessary to abstract from their concrete content. The steps that are typical for system building are carried out. The processes that occur usually have a signal character , i.e. H. the processes encountered in the various MMSs are understood as information flows and the corresponding MMSs as information processing systems .

Aspects of task processing

When working on a task , three aspects must be distinguished:

Processing status,
Processing means and
Processing target.

If one of these aspects is only incompletely known, one speaks of a problem ; The processing of such a task then includes problem-solving processes .

Time requirements for task processing

The time scale on which the task processing is to be carried out can range from fractions of a second to hours, in management information systems, for example, even up to months. The decisive factor here is at what intervals and within what period of time the surgeon has to perform the interventions. Furthermore, a distinction must be made between

unique,
repeated (intermittent, i.e. not regular) and
constant (repetitive, i.e. regularly recurring, continuous or quasi-continuous)

Interventions. Only in the case of one-off interventions can one assume that the overall behavior of the MMS is static. In all other cases, there is a dynamic system , characterized in that the current processing step - apart from the goal - also depends on the previous step (s).

Task priority

When accompanied by more than one task ( multitasking be decided) should be which of the tasks with priority ( priority ) is done. This priority is a property of the associated processes and is closely related to the time requirements for their processing.

Task complexity

The complexity of a task depends on the one hand on how many dimensions its processing states include. On the other hand, it depends on the scope, the degree of determination and the complete description of the above-mentioned aspects and their mutual dependencies.

Investigation methods

Findings about human-machine systems are gained through observation in real situations (for example in the context of a task analysis ), through the use of test subjects on simulated technical systems (for example in driving, flight or process simulators) or using models for won over people .

literature

Gunnar Johannsen: man-machine systems . Berlin: Springer-Verlag, 1993. ISBN 3-540-56152-8 .
William R. Rouse: Systems Engineering Models of Human-Machine Interaction . New York, Oxford: North Holland, 1980.
Gavriel Salvendy (Ed.): Handbook of Human Factors . New York: Wiley, 2006. ISBN 978-0471449171 .
Thomas B. Sheridan, William R. Ferrell: Man-Machine Systems: Information, Control, and Decision Models of Human Performance . Cambridge: MIT Press, 1974.
Thomas B. Sheridan: Supervisory Control. In G. Salvendy (ed.): Handbook of Human Factors . New York: Wiley, 1987.
Thomas B. Sheridan: Humans and Automation: System Design and Research Issues . New York: Wiley, 2002. ISBN 978-0471234289 .
Klaus-Peter Timpe, Thomas Jürgensohn & Harald Kolrep (eds.): Man-machine system technology. Concepts, modeling, design, evaluation . Düsseldorf: Symposion, 2002. ISBN 3-933814-83-9 .

Web links

Wiktionary: Man-machine system - explanations of meanings, word origins, synonyms, translations