The successful start of implementation of live working and the possible effects on maintenance of distribution network

It has been a successful period of introduction and implementation of live working (LW) for the Slovenian distribution network. On the basis of the acquired abroad proven technologies of the implementation of the LW at low voltage (LV) and medium voltage (MV) levels the system manuals and work instructions were made, basic training in a specialized ground are carried out and personal protective equipment (PPE) and gear are provided. Experts in the distribution, outworkers, and operators of technology, training, and instructors are united in the assessment to respect the principles of safe work in implementing LW in practice. LW needs encouragement of company managements, as this new method of maintenance has not yet been fully developed. Abroad LW at LV and MV became practically the only acceptable standard implementation or maintenance of the distribution network, overhead lines and transformer stations respectively. High quality standards for power quality (PQ) from the standpoint of the length of the specified duration and frequency of interruptions of supply to customers, is forcing distributions managements to consistent implementation of LW at LV and MV. National energy regulators are ensuring transparency, impartiality and equal rights to all participants in the energy markets and adopting PQ standards that are stricter over years. They also pursue various measures and compensation schemes or incentive scheme for system operators. Analysis of the European region confirms that those distributions that carry out LW are efficient and effective

Joint maintenance-inventory optimisation of parallel production systems

We model a joint inspection and spare parts inventory policy for maintaining machines in a parallel system, where simultaneous downtime seriously impacts upon production performance and has a significant financial consequence. This dependency between system components means that analysis of realistic maintenance models is intractable. Therefore we use simulation and a numerical optimisation tool to study the cost-optimality of several policies. Inspection maintenance is modelled using the delay-time concept. Critical spare parts replenishment is considered using several variants of a periodic review policy. In particular, our results indicate that the cost-optimal policy is characterised by equal frequencies of inspection and replenishment, and delivery of spare parts that coincides with maintenance intervention. In general, our model provides a framework for studying the interaction of spare parts ordering with maintenance scheduling. The sensitivity analysis that we present offers insights for the effective management of such parallel systems, not only in a paper-making plant, which motivates our modelling development, but also in other manufacturing contexts

Raziskava učinkov dela pod napetostjo na nizki napetosti med slovenskimi vzdrževalci električnih inštalacij in postrojev

Live working (LW) as a tool for preventive maintenance of electrical installations has a hundred year tradition in the world and more than half a century in Europe. In the last decade, LW has been implemented actively at low voltage in the Slovenian electrical distribution, transmission and generation of electricity as well as in industry and institutions (such as health). Slovenian electrical distribution began with the introduction of LW at low voltage in 2010. Depending on the complexity of the implementation processes, several special studies which define organizational activities, working documents, prescribe the necessary tools and personal protective equipment are being made. Likewise, a specific training program is defined, as well as the required number of workers and instructors, and analysis of the effects of LW at low voltage. The purpose of this paper is to examine whether we can achieve compliance with the requirements for the safety and health, the quality and the effectiveness, and efficiency of maintenance processes with the implementation of LW at low voltage. It is evident from the survey results that safety and health was highlighted as the most important field from the perspective of workers and instructors. It can be summarized that the results of this study demonstrate that workers and instructors in all of the surveyed distributions are aware of positive effects of the introduction and implementation of LW at low voltage. Based on the results and discussions, guidelines for the implementation of the LW at low voltage are given in this study. Given the fact that workers and instructors highlighted safety and health at work we suggest that regular supervision procedures continues within the implementation of individual work orders, and that possible hazard situations have to be assessed at two year cycles of verifying workers and instructors competences

Study on the quality management and health and safety aspects on perceived live working implementation dimensions

The purpose of this paper is to compare the quality management and safety aspects within the Live working (LW) framework. The study draws upon study carried out among the Slovenian electrical distribution and international study which was carried out among Slovenian and foreign LW experts. The results of the first study suggested that health and safety aspects of LW are vital for achieving efficiency and effectiveness of LW. Furthermore, it can be argued that there are no substantial differences among workers and coordinators. Similarly, the results of the international survey showed that health and safety aspects of LW are considered as very important in achieving desired outcomes of LW as expressed by the foreign LW experts. However, the results indicated that Slovenian experts perceived the elements of LW in a similar way as foreign experts