Man-machine-environment systems

In the case of a harmonious development of the Man-Machine-Environment system, safety supervisors should keep in mind the awareness of danger, and should not slack in this respect. If we can keep self-alertness, repercussions will not happen. 

The interlinking of cybernetics and the science of safety results from the fact that technical installations are operated and monitored by human beings who are involved within the effective range of that same installation. They are using the machine but are likewise exposed to its dangers. Human behavior as well as the behavior of the machine, on the other hand, are dependent on the conditions of their environment. The environment, in turn, is often influenced by them in various ways, e.g., by the production of waste, sewage, noise, and alien substances into the air. Man, on the other hand, is able to influence these environmental factors. Each and every technical installation is thus embedded in a man-machine-environment-system characterized by mutual interaction (Figure 3.12). 

Figure 3.12 Basic cybernetic schematic design of the man-machine-environment-system (MMES).

Figure 5.1 The function of the machine within the man-machine-environment-systems.

The aim of this chapter is to elaborate on the personal characteristics of man described by the human sciences and their utilization for the planning of a man-machine-environment-system. Sections 6.1, Medical Aspects, and 6.2, Psychological Aspects, are meant to approach this problem in a detailed way. The human sciences must provide specialized information on as high a measurement level as possible. 

For the safeguarding of the entire active system of man-machine-environment, exactly the same principles are applied as have been referred to in Reliability and Suitability of Machines. In the case of man, the pertinent procedures can likewise be subdivided into planning, control, and testing. During the planning of a man-machine-environment-system, the anatomical data of the human body and its physiological processes and functions must be taken into account as contributory prerequisites in the same way as the stress characteristics of a material used in the construction of a machine. 

When planning complex man-machine-environment-systems, the natural equipment of the operator, namely man, will have to be taken into account with some of his specific psychic and physical functions and the possibilities of compensating for them, and in some cases minimum values will have to be established. The science called ergonomics deals specifically with the problems of workplace design as far as creating humane working conditions, the proper performance of the technical system, and improved safety in the workplace are concerned. 

Figure 6.1 Model of feedback control system man-machine-environment-system.

The exemplary demonstration of an aptitude test shows the problems which must be overcome in the course of integrating man into the man-machine-environment-system (MME-systems). 

The dangers to people inherent in a specific work process within the man-machine-environment-system are often not directly perceived, but merely estimated. In this estimation process considerable errors can occur. Studies in the coal and ore mining industries concerning the relationship between actual and estimated risk have shown that there are only relatively insignificant correlations between the range of objective risks and subjective assessment, This does not mean that the people involved are incapable of differentiating between the various work procedures, but rather, as Burkhardt [6-36) points out, that errors in the estimation of danger are made, which means that the possibility for accident-free work will be low. 

Because humans often constitute a special problem within the man-machine-environment-system, it is of vital importance that human capabilities and limits be taken into account in every phase of system development. This is the task of systems ergonomics, which may be regarded as fitting the technology to the man. 

An important effect of noise emissions in a man-machine-environment-system is the disturbance in verbal communication. When full understanding of sentences is required, the interference sound level for normal messages should be no higher than 10 dB (A) below the speech sound level. For unusual or difficult messages this difference should be increased to 20 dB (A). The maximum distance between speaker and listener which still ensures satisfactory communication can be derived from the speech interference level (SIL). The SIL is the arithmetic mean of the octave sound level in the four octaves with the mean frequencies of 0.5/1/2/4 kHz. Table 6.21 shows the maximum distance between speaker and listener for various SILs. 

In order to avoid dangers within the man-machine-environment-system, the efforts directed towards the promotion of safety-related behavior or towards changes in human behavior aimed at preventing accidents should be considered. For these purposes the principles of learning are applied, about which some basic statements need to be made. 

The central problem with any bonus or sanction system, or even all safety campaigns aimed at work processes in the man-machine-environment-system is that, irrespective of whether positive or negative intensifiers... 

In the first few chapters, the man-machine-environment-system (MMES) was described in a system-theory-related approach and later described in detail. The role of safety legislation in this connection was not considered. We will now proceed with an examination of the importance of the legal system for safety legislation and shall begin with an attempt to determine where and how it can be integrated into the MMES. 

Technology assessment deals with interaction within man-machine-environment-systems and its time linkage in a manner quite different from other disciplines. Viewed in the context of the short and medium terms, social effects and reactions which deserve particular emphasis in safety science are dealt with. There are, however, often difficulties with doing justice to the problem, since connections are frequently unknown and corresponding measuring concepts are not extant. It is hoped, however, that the desired information basis can be created by means of social indicators, but this development is only beginning. 

Huang D.S., 2005, Manned Space Environment stress and Hunman Reliability, The 7th Man-machine-environment System Engineering Academic Meeting. 

The notion culture conies from Latin, and it means a summary of material and spiritual results of human activity. Therefore, if we talk about culture safety, it will mean a summary of all human activities that create conditions for safe work, and life, in the Man-Machine-Environment system (Figure 1.1). A prerequisite for implementing a safety culture is the creation of such conditions, where safety and health protection is a joint task of employers and employees on any level of business management. Accepting this principle has to be conditioned by the fact that health protection has the highest priority in any society and in any sphere of people s lives. 

A safe machine construction is a prerequisite for executing safe activities within technological processes within the Man-Machine-Environment system. Only safe and functional machines, or complex machine systems, can complete the circle of quality so that the result will be a high-quality product with the potential to sell well. 

The current development of management systems significantly affects the integration of OHS into any management process. At the same time, requirements for the complexity of solutions in the field of OHS, especially those of the Man-Machine-Environment system, and for any work-related aspects, are increasing. As a human factor, a person (man) is an important element of this system, though it is necessary to perceive them with regard to other elements. 

Expectations for a Single Approach within Risk Management in the Man-Machine-Environment System... 

The basic requirement imposed for mechanical systems, technologies, and machines stems from the assumption that a product has to be safe during any of the stages of its technical life, that is, even during its operation, including maintenance and repairs. These features must be provided within the Man-Machine-Environment system as well as when taking into account their mutual influence. It is in fact this system that is subsequently the object of executing safety analyses. 

Utilization of technical diagnostics methods, when taking into account the reliability of results, is only one of the basic tools for effective maintenance management and elimination of undesirable conditions (hazards) as aresnlt of technical or human factors affecting the safety of the Man-Machine-Environment system. 

Recently, the notion of culture has been often used during the application of new management systems. This word has its origins in Latin and means the summary of material and spiritual results of human activity. Thus, if we talk about safety culture, it means the summary all human activities that create conditions for safe work and life in the Man-Machine-Environment system. As for quality culture, it means the creation of conditions for execution of any activity within the quality management systems in order for them to result in a final product that meets the requirements of interested parties. 

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