Among the many publications on the environmental life cycle assessment (LCA) of transport, there are only a few examples of works dedicated to means of internal transport. For this reason, it was decided to gather energy-oriented inventory data and to assess the environmental impact related to the operation of selected forklift trucks, as the most commonly used means of internal transport. This paper presents the main assumptions and the results in relation to the four phases of LCA: the goal and scope definition, the life cycle inventory, the life cycle impact assessment results, and the interpretation. Ten forklifts with different engines were selected in order to carry out the life cycle assessment study. The research was based on the results of measuring the operating fuel consumption and exhaust gas emissions, conducted using the SEMTECH-DS mobile device from the PEMS group of devices. In order to make the measurements under a circumstance close to the real conditions of forklift exploitation, it was decided to slightly modify the operating cycle proposed in VDI 2198. The environmental impact of the fuel/electricity usage and exhaust gas emissions was assessed using the ISO 14040x guidelines and the IMPACT 2002+ method. The study showed that using an electric forklift to transport 1 t of payload over a distance of 1 km has a significantly smaller environmental impact than using one of the selected forklifts powered by an internal combustion engine. Using forklifts powered by liquefied petroleum gas (LPG) engines leads to a significantly higher environmental impact whilst the use of vehicles with diesel engines has an impact at a level several times lower. In a case of drives without load, where functional unit was defined as covering 1-km distance with no vehicle load, a lower impact for the electric vehicles was also obtained. The analysis includes the influences of the upstream processes of fuel and electrical energy production. Even when Poland’s production scenario (based almost entirely on fossil fuels) is taken into consideration, the electric forklifts still show a clear advantage. It should be expected that, if the technological mix of electrical energy production for countries with a higher share of renewable or nuclear energy were to be taken into account, the environmental indicators for electric vehicles would be even lower. It is worth noting that only the energy aspects of forklift operation were analysed. Further studies aiming to collect inventory data relating to other exploitation aspects, as well as the production and utilization of the same vehicles, are planned as a continuation of this research.

Maintaining high efficiency of using the fleet of public mass transport vehicles puts many challenges ahead of the operator. Among them, when planning periodic operational activities, the operator should take into account the assessment of possible unexpected vehicle failures and the costs of their removal under the so-called corrective maintenance. Due to the random nature of vehicle breakdowns, knowledge about stochastic processes is necessary to maintain their efficient and safe operation. The research problem formulated in the title meets these needs. Therefore, the costs of corrective maintenance of vehicles are modelled, i.e. the costs that are not included in the scheduled maintenance costs and are not related to preventive maintenance. The costs of corrective maintenance and the costs of replacement of damaged parts are unexpectedly created at random moments of operating means of transport, usually between scheduled maintenance. Due to the variety of failure processes of individual parts of the vehicle, the methods and applications of stochastic modelling for simple failures modelled by the Poisson process are presented in this paper. The basis for the application of the presented methods is to identify those parts of the vehicle that are damaged in accordance with this process. The assessment of parameters of failure processes of individual vehicle parts is made on the basis of the operational database of a homogeneous fleet of vehicles operated for 5 years. The operational database is dynamically updated with new events. On the basis of actual data on corrective maintenance of a distinguished group of damaged parts of vehicles, the possibilities and limitations of practical applications of the Poisson process to assess the risk of incurring costs in the further process of fleet operation were shown.

This paper presents an aggregate method of selecting a theoretical cumulative distribution function (CDF) for an empirical CDF. The method was intended to identify the time of reliable operation of a renewable technical object by applying three criteria based on the following statistics: the modified Kolmogorov–Smirnov (MK-S) statistic, the mean absolute deviation of the theoretical CDF from the empirical CDF, and a statistic calculated on the basis of a log-likelihood function. The values of these statistics were used to rank eleven probability distributions. The data for which calculations were made concerned failures of the driver’s cab lock recorded during five years of operation of a fleet of 45 trams. Before calculating the statistics, the empirical CDF of the examined component was determined using the Kaplan–Meier estimator, and then, using the method of Maximum Likelihood Estimation, the parameters of the analysed theoretical distributions were estimated. The theoretical distributions were then ranked according to the values obtained for each of the assumed criteria: the lower the value for a given criterion, the higher the ranking position, indicating a better fit according to that criterion. Then, based on the three rankings and on weights assigned to the individual criteria, an aggregate criterion (referred to as DESV) was implemented to select the best-fitting probability distribution. The method assumes that the lowest DESV value corresponds to the best-fitting theoretical distribution. In the case of the examined component, this was found to be the generalised gamma distribution. It is shown that if the final decision is based on the aggregate criterion, which takes into account the three criteria for goodness of fit, the reliability of the estimation of the time-to-failure distribution increases, and thus mistakes resulting from the use of only one of the criteria can be avoided.

The analysis of the reliability parameters of a technical object and the determination of the change in the reliability of the object over time, requires the knowledge of the functional characteristics and reliability parameters of the elements included in a system. On the basis of the failure data of the selected element of the object, in this case the vehicle, it is possible to determine the average working time to failure of the element and the appropriate form of distribution that characterizes the reliability and durability parameters of the tested element. The main purpose of the research presented in the article was to develop a method of assessing the reliability of an electronic component of a vehicle-a boot lid contactor. This paper also presents three possible methods of repairing the boot lid contactor (sealing the housing with adhesive with better way, replacing the element with a new one or the most time-consuming solution, changing the shape of the boot lid). The authors also decided to determine the reliability and cost parameters that will allow preventive replacement of this element. The tests were carried out on a fleet of 61 vehicles of the same model, but with different body structures. Contactor failures were reported in 41 cases, of which 29 were in the hatchback construction and 12 in the estate type. The analysis of the distribution selection for the tested part of the passenger car-the boot lid contactor-was performed using the Likelihood Value (LKV) test to determine the rank of distributions. Also the maximum likelihood (MLE) method was used to estimate the distribution parameters. The three-parameter Weibull distribution was the best-fitted distribution in both cases. It was clearly defined that one model of car with two different types of body have vastly different reliability characteristic. Based on the reliability characteristic and parameters, the appropriate preventive actions can be taken, minimizing the risk of damage, thus avoiding financial losses and guaranteeing an appropriate level of vehicle safety.

The article presents a two-dimensional comparison of the alternative manufacturing processes of laminates used in food industry packaging. The main aim of the presented study was an assessment of potential environmental impacts occurring during the production of two-layer laminates containing a patented polypropylene film Metallyte™ 28UBW-ES and the hitherto used pap/LDPE/Al/LDPE multilayer laminates. The environmental assessment was supplemented by a cost calculation with special regard to the investment required for the production of the two-layer laminates. In the research both the life cycle assessment and the life cycle cost methods were applied. Based upon the obtained environmental impact indicator and the discounted costs the eco-efficiency indicator was determined. The results of the comparative analysis are shown on a two-dimensional eco-efficiency diagram. Based on the conducted study it was found that replacement of traditional packaging materials by laminates containing the Metallyte™ 28UBW-ES structure is justified. This is illustrated by a higher eco-efficiency indicator. The difference in the costs between the manufacturing processes under analysis is relatively small. However, when it comes to the environmental impact, there is a clear disproportion in favor of the two-layer laminates.

Kaplan–Meier analyses can be used in many disciplines, e.g., agricultural engineering. Agricultural machinery and vehicles can be regarded as objects that ‘die’ because, like living creatures, they failed, although after repair they can be used until scrapped. This article presents an example of using the Kaplan–Meier estimator to plot the reliability function curves of five different models of Zetor farm tractors. The research shows that the median operating time for one of the tested models, which is about 200 engine-operating hours, is 20% lower than for the entire population of analyzed Zetor tractors. This means that the quality of the model, which is very popular in Poland, differs significantly from the other models of this manufacturer. The method cannot be validated, due to a lack of similar functions for other brands of tractors. Progressive automation and digitization of agriculture can contribute to improving the reliability of agriculture work. The user can focus on the correct performance of agrotechnical treatments, and modern control systems will signal in real time, about identified or approaching costly failures.