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The basic work site settings are passive means in the sense that they are not used as a tool which is part of the active productive work process. Work site settings include artificial means for accommodation, furnishing and accessories like e.g. illumination or air conditioning. Non-powered tools at the disposal of the operator are tools like maps, screw drivers as workshop tool and other tool box items, bicycles as vehicles and others. All powered tools belong to the category of machines. For the work objective "to move for a visit to relatives at some other place in town", for instance, the technical means of transportation like an automobile is a typical powered tool as part of the operation-supporting means of the corresponding work system. This is true as long as all changes of the state of this machine is totally controlled by the operating force of the work system it belongs to (in this case by me). Otherwise it would belong to another entailed work system. Therefore, both, whether your friend gave you a courtesy ride, or if you were using public transportation, this would not be an operation-supporting means of the work system you are operating while being transported.
In fact, you would have been the work object, i.e. a part of the material supply input of another entailed work system with an operating force you did not belong to. To offer another example for a machine as powered tool apart of any motorised vehicles, let us think of a drilling machine which our dentists use. This machine has in common with a motorised vehicle that it is totally controlled by the human operator. Opposed to the powered tools there are other machines as sub-systems which provide so-called automated functions. They may stand for themselves like a robot or a multi-agent system, or are built into a powered tool like modern car equipment such as ABS (Anti-lock Braking System) or automatic speed control. All this belongs to the special sub-category of machinery which is called automation. Regarding the scope of this article, automation within a work process stands for any technical function, which partially or fully carries out a control or information manipulation task which, in the last place, is defined by an autonomous entity like the human operator, and which otherwise a human operator would have to accomplish. As already mentioned corresponding functions of automation can be subsumed under:
• automation of information acquisition and delivery,
• automation of system control, and
• automation of system management.
Automation has become a major playground for engineers in order to enhance the work system performance. In the context of this article sub-systems of automated functions in vehicle guidance and control are in our primary focus. Thereby, these sub-systems, on the one hand, can appear as built-in systems which are not necessarily recognisable by the human operator as such, because they are working on a self-contained basis, once the work process is initiated. Their impact on the work system output can be a direct or an indirect one. The ABS in our cars, for example, which was mentioned above, directly impinges on both the work product as the way the car is moving as well as the work state as the state of progress of the transportation task. An automatic display function, however, changes only the internal work state without any immediate effect on the work system output. The authority level of these systems may range from low to full authority, depending on the reliability and the certainty that it cannot violate the work objective by any means. On the other hand, there are sub-systems of automation at the disposal of the operating force which need to be activated each time when required, like the automatic speed control as mentioned above, too. These sub-systems often work with full authority, when activated, but they might be overdriven or turned off by the operating force at any time. Apparently, it is up to the operating force to decide whether to allocate a task or sub-task execution at this sub-system. Depending on the functions these sub-systems represent, their impact on the work process output can also be both, a direct or an indirect one. It is offering scales of levels of automation (LoA) in different dimensions, like for:
• the degree of specifity required of the human for inputting requests to the machine,
• the degree of specifity with which the machine communicates decision alternatives or action recommendations to the human,
• the degree to which the human has responsibility for initiating implementation of action, and
• the timing and detail of feedback to the human after machine action is taken.
These days, operational systems go as far as incorporating robots as part of the operation-supporting means which exhibit some kind of artificial cognition. Automation has probably become the most emphasised area in system design during the past decades. The effects of automation, as they were experienced so far, were satisfying to a great extent, but there were severe disappointments, too. We consider operation-supporting means exclusively as artefacts. This does not exclude external manpower supporting the work process. In that sense we rather deal with supporting manpower as separate supporting work systems instead of embedded ones as part of the operation-supporting means. This does not make any functional difference but it provides clear-cut entities with respect to autonomy allocation. System engineers need to break down large-scale systems into clear-cut entities in order to keep them manageable in the design process as well as during operation. The autonomy of the operating force should not be contaminated by any other autonomous party as part of the operation-supporting means. With the increase of automation there are many operation-supporting means, which originally were work systems having been replaced by an artificial sub-system. One can say in general that a work system, originally being operated by a human operator, looses its status of being a work system and converts into an operationsupporting means, once its objective will be accomplished by an artefact without any human operator involved.
The bounds and the performance of the operationsupporting means of a work system are crucial design characteristics. They depend on the layout of the work objective, the operating force, and the other interacting work systems and the technology used. The work process performance crucially depends on the interplay of the operating force and the operation-supporting means and the characteristics of the operation-supporting means. The charm of the concept of the work system lies in the fact that a complex work environment can be broken down into convenient partitions, handy enough for investigations. This partition can be easily and unambiguously described and delineated by corresponding work objectives and pertinent work systems and work objects. This is the platform, from where it can be investigated how the performance of the respective work process can be enhanced, for instance by exploiting new potentials of technology. Thus, the work environment usually comprises a system of interacting work systems. It was already mentioned a configuration of two interacting work systems where the work system concerned is manipulating a work object as an active system which in turn is a work system by itself.
The latter work system, here also considered as the work object, is for instance manipulated by the instruction of a certain work objective as generated by the other work system. All work systems correspond to respective work objectives in a one-toone relationship. The whole of process knowledge embedded in the operating force of a work system decides about its delineation from interacting work systems in other levels. Although it is possible that the work objective of an upper-level work system is known, merging with that one is not reasonable, if there is too much lack of process knowledge about the upper level work process. There are different ways of interaction of work systems, depending on the inputs or outputs through which the interaction links are established. One category of systems of work systems is that one structured by a work hierarchy. This is typical for the work environment of organisations like a company. In a work hierarchy of work systems these systems are linked by the work objective forwarded as work system output on the higher hierarchy level and as input of the work system on the lower work hierarchy level. The work system, which is operated by the airline flight operation executive board, provides the objectives for the airline flight dispatching work system, and the work system operating the flight dispatching provides the flight objectives of the various airline flights, which are to be met by the corresponding work systems with the pilots as operating force.
The other possible category of systems of work systems is characterised by a network work structure. A network of work systems is characterised by links between them which are providing any inputs other than work objectives. Thus, there are supplying work systems and receiving ones. It may also happen that the supplier in this case is one of the work systems which were previously a receiver. Therefore, in general, these work system networks are omni-directional. It becomes obvious that work system networks include concurrent activity of participating work systems. The work systems of the various airline flights receive air space clearance information from an ATC work system, and the ATC work system receives information about the state of the airline flights from the respective flight work systems.