The objects of the study are parallel-structure machine systems with redundancy associated with safety assurance of continuous material flow. The problem concerns systems in which the supply of materials takes place continuously (24 hours a day), and the system of operated machines must ensure the receipt and movement of the material at a strictly defined time and in the desired quantity. It is a system where the presence of a failure poses a threat to human life and environmental degradation. This paper presents a method for system condition assessment and upgrading for maintaining proper operation under conditions of continuous operation. A database of information about the current parameters of the system components (measurements, monitoring) is necessary for condition assessment. The method also uses lean techniques (including TPM). System evaluation and selection criteria for a suitable structure in terms of further operation were proposed. Exemplification was performed for an underground mine drainage system. As a part of the identification, selected parameters of the system components were measured, and their characteristics (motors, pumps, pipelines) were developed. The results of the analysis and the values of the adopted criteria were compared to the indicators for new pump sets. A two-option system upgrade was proposed, in addition to machine operating schedules, maintenance periods, and overhaul cycles.

An important problem associated with the production of steel products is the need to ensure adequate protection of the environment. Throughout the technological foundry formed about 90 types of waste, while a significant number of them belongs to a group of hazardous waste. Resulting in the production system have a steel mill waste utility value to justify the economic and ecological use, not only in the steel sector but also in other sectors of the economy. There is a need to increase activities related to environmental waste management from manufacture of steel, particularly those whose development is one way of storage. The paper presents the concept of reverse logistics in the specific example of a steel mill a full production cycle and the overall costs generated within the waste management system of a full production cycle steel mill.

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In multi-tier distribution, in addition to suppliers and consumers there are also intermediaries who participate in the transfer of products from manufacturers to end consumers. The choice of the distribution system depends on the optimisation of the performance indicators for servicing an area, taking into account the technical capabilities of the individual logistics chain links. The paper compares two typical distribution structures in the construction sector. The choice of the structure is a function of the manufacturer’s economic and organisational determinants. The paper presents a model representing the costs of two typical distribution structures in the construction sector. The choice of the structure depends on the company’s outsourcing policy and total costs of all three major system components: the distribution network, transport network, and warehousing. Rationally built and implemented functioning models are a key element of business success in the marketplace. The choice of a suitable strategy is difficult, as it depends on many dynamically changing parameters which directly affect costs. In addition, the relations between the system elements are very complex and interdependent.

Zinc oxide concentrate production is performed in the so-called rolldown process with the use of rotary furnaces. It is a complex technological process in which the zinc-bearing waste harmful to the environment is used as raw material. Incorrect process execution will cause a large number of unplanned stops. Three upgraded technological lines used for the production of concentrated zinc oxide at B. Recycling Sp. z o.o. company were analyzed. The purpose of the study was to determine the production process efficiency after implementation of the changes. In the study we used the Total Productive Maintenance method. We made the histograms for planned downtime and failures of individual technological lines for a period of one year and set the MTTF, MTBF and OEE indices. Analysis of results has allowed to propose a solution to shorten the failure duration.