Industry 4.0 will affect the complexity of supply chain networks. It will be necessary to

adapt more and more to the customer and respond within a time interval that is willing

to accept the product waiting. From these considerations, there is a need for a different way

of managing the supply chain. The traditional concept of supply chain as a linear system,

which allows optimizing individual subsystems, thus obtaining an optimized supply chain, is

not enough. The article deals with the issue of supply chain management reflecting demand

behaviour using the methodology Demand Driven MRP system. The aim of the publication

is to extend the knowledge base in the area of demand-driven supply logistics in the

This paper describes practical issues related to control of the active power buffer (APB) developed for a 2 kVA single-phase inverter. The buffer is designed using the latest GaN HEMTs controlled with triangular current mode to reduce switching losses, however, the switching frequency should be limited to 1 MHz. In the case of the presented analogue-digital controller, frequency is influenced by a reference current of the APB and circuit. Therefore, the operation at start-up and shut-down is especially challenging. A modified control algorithm that also includes pre-charging and discharging process of the energy buffer is presented and experimentally verified by series of tests of the 2 kVA GaN based inverter with the APB.

The introduction of a baseline term to the dependency network most often results in a change, break and/or generation of a new sequence of critical path, depending on the type of such a baseline term and the exact date selected. Each of those situations has an impact on the location or need to include new time buffers in the modified Goldratt’s method. The purpose of this article was to identify possible effects brought by declaration of each type of baseline term and to point out actions to be taken in each case. It must be noted that guidelines provided should in each individual case be adapted to the specific character of schedule changes caused by implementation of the relevant baseline term. The example presented herein exemplifies one of such solutions to be implemented as a result of break of the critical path and need to introduce new time buffers.

The paper presents a Car Sequencing Problem, widely considered in the literature. The issue considered by the researchers is only a reduced problem in comparison with the problem in real automotive production. Consequently, a newconcept, called Paint Shop 4.0., is considered from the viewpoint of a sequencing problem. The paper is a part of the previously conducted research, identified as Car Sequencing Problem with Buffers (CSPwB), which extended the original problem to a problem in a production line equipped with buffers. The new innovative approach is based on the ideas of Industry 4.0 and the buffer management system. In the paper, sequencing algorithms that have been developed so far are discussed. The original Follow-up Sequencing Algorithm is presented, which is still developed by the authors. The main goal of the research is to find the most effective algorithm in terms of minimization of painting gun changeovers and synchronization necessary color changes with periodic gun cleanings. Carried out research shows that the most advanced algorithm proposed by the authors outperforms other tested methods, so it is promising to be used in the automotive industry.

A method of creating production schedules regarding production lines with parallel machines is presented. The production line setup provides for intermediate buffers located between individual stages. The method mostly concerns situations when part of the production machines is unavailable for performance of operations and it becomes necessary to modify the original schedule, the consequence of which is the need to build a new schedule. The cost criterion was taken into account, as the schedule is created with the lowest possible costs regarding untimely completion of products (e.g. fines for delayed product completion). The proposed method is relaxing heuristics, thanks to which scheduling is performed in a relatively short time. This was confirmed by the presented results of computational experiments. These experiments were carried out for the rescheduling of machine parts production.

Railway buffers during the operation are staying in almost permanent contact with each other, creating friction node in the point of contact

of two railway buffer heads. In consequence of overcoming track curves, turnouts and unevenness of track, the railway buffer heads moves

relative to each other causing friction, which results in its wear. When the wear is excessive, it might be a reason to withdrawn vehicle

from service, it causes flattening of buffer head, and in consequence its abnormal cooperation. To avoid this phenomenon the buffer heads

should be covered with graphitized grease, but this method has many disadvantages. Accordingly, it was found that it would be beneficial

to cover the buffer head with bronze using laser cladding. In this article the metallographic and mechanical analysis of the newly created

top layer of railway buffer head are presented. In article the results from tribological tests conducted on Amsler test bench are also

presented. Based on test results described in article concluded that the layer of bronze coat on working surface of railway buffer head can

be beneficial from operational point of view.

The article presents the problem of the settlements development in the Ojców National Park (ONP) and its buffer zone, both located in the suburban area of Cracow (Poland). The aim of the research was to recognize the social perception of this phenomenon, as well as the residents opinion about the limitations in spatial management related to the functioning of the Park. Interviews were made among 204 residents, and 40 representatives of local self-governments, cultural institutions, associations, administrators of tourist facilities and entrepreneurs. The local community perceives constraints in the new buildings construction and in enlargement or modernization of the existing ones as the main problem for people living in the ONP or its buffer zone. Driven by their particular interests, residents advocate the further development of the settlements and tourist infrastructure within the Park and the buffer zone, the liberalization of regulations, and even the liquidation of the Park’s buffer zone. They do not understand that the natural and landscape values (highly appreciated by them) can be degraded due to these activities.