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The current practice and the requirements of industrial enterprises in all industrial areas require a detailed display of manufacturing systems course of events. In this paper, we studied the effects and impacts of computer simulation to improve the actual industrial production. We also verified whether the proposed simulation model and its intervention in the logistics of concrete production in a concrete manufacturing enterprise will correspond to reality. The EXTENDSIM simulation software was used. The simulation results utilization in practice has increased the actual production several times. The simulation results indicated that it is necessary to double the intensity of company supply, i.e. a frequency of entry set to 0.15 days for each timber type. This adjustment increased the performance of unutilized devices and the whole manufacturing system several times, up to 54,475 produced building timber elements, which represents an increase of production by about 199.6% while maintaining company flexibility. [ABSTRACT FROM AUTHOR]

The article presents the problems connected with the performance evaluation of a flexible production system in the context of designing and integrating production and logistics subsystems. The goal of the performed analysis was to determine the parameters that have the most significant influence on the productivity of the whole system. The possibilities of using automated machine tools, automatic transport vehicles, as well as automated storage systems were pointed out. Moreover, the exemplary models are described, and the framework of simulation research related to the conceptual design of new production systems are indicated. In order to evaluate the system's productivity, the use of Overall Equipment Efficiency (OEE) metrics was proposed, which is typically used for stationary resources such as machines. This paper aims to prove the hypothesis that the OEE metric can also be used for transport facilities such as Automated Guided Vehicles (AGVs). The developed models include the parameters regarding availability and failure of AGVs as well as production efficiency and quality, which allows the more accurate mapping of manufacturing processes. As the result, the Overall Factory Efficiency (OFE) and Overall Transport Efficiency (OTE) metrics were obtained. The obtained outcomes can be directly related to similar production systems that belong to World Class Manufacturing (WCM) or World Class Logistics (WCL), leading to the in-depth planning of such systems and their further improvement in the context of the Industry 4.0. [ABSTRACT FROM AUTHOR]

Flexible protection barriers are often located on the mountainsides in order to decrease the risk of rockfall. In the present study, different scales of experimental tests are considered, to gauge the behaviour and to estimate the bearing capacity of a new type of cable-nets used for these flexible barriers in case of quasi-static loads. A large experimental campaign addressing cables characterization, as well as the behaviour of the constitutive cells of the net, which particular shape, a water drop shape instead of the classical rings, induces asymmetric loading transfer. Finally, the net behaviour itself is characterized through appropriate tests. These tests highlighted the non-linear behaviour perceived at different scales and permitted to evaluate the bearing capacity of the various components. Numerical simulations using the finite element code Abaqus were also conducted for the different components, a group of constitutive cells with rigid or fuse clip or the whole net, to reproduce the behaviour observed experimentally. [ABSTRACT FROM AUTHOR]

Modeling forms the basis for optimal control of complex technical processes in the context of industry 4.0 development and, hence, for high product quality as well as efficient production. For the mechanical joining process of self-pierce riveting with 11 input and 5 output variables, two modeling approaches based on (1) experimental data and (2) FEM computer simulation are outlined and performed. A physical modeling approach is ruled out due to the high problem dimensionality and complex nonlinear dynamic relationships between input and output variables. Alternatively, data-based approaches lead to Artificial Intelligence (AI) model designs. The experimental approach is cost- and resource-consuming; therefore, only a relatively small data set can be collected. Here, we present results from experimental trials that serve as representatives and are generalized by a description with high-dimensional parametric membership functions (fuzzification). The fuzzification procedure is also applied to the FEM computer simulation results. In principle, it can provide an arbitrarily large database. However, consequently, time- and computational effort increase considerably. Both data sets form the basis for parallel model building using the AI method of local fuzzy pattern models, which can be used to describe highly nonlinear input-output relationships by error-minimizing partitioning. Finally, the comparison of the results of the two modeling approaches is outlined. Finally, a coupled modeling strategy and future model adaptation are proposed. [ABSTRACT FROM AUTHOR]

This paper deals with a flexible production system modeled by re-entrant queueing network; a system decomposed into two fundamental multi-productive stations and three classes, a part follows the route fixed by the system, where each one is processed first by station 1 for the first step, then by station 2 for the second step, and again by the first station for third and last step before leaving the system. We assume that there is an infinite supply of work available, so that there are always parts ready for processing step 1, and that the first station gives preemptive priority to buffer 3. Several performance measures have been used to evaluate the system performances considering two scenarios; high priority with service conservation and high priority with loss of parts. So, performances due to varying its parameters are investigated through expanded Monte Carlo simulations. [ABSTRACT FROM AUTHOR]

The research and development of flexible forming technology have a crucial role in the personalized production and manufacturing of three-dimensional (3D) surface sheet metal parts. Three-dimensional surface rolling with rigid arc-shaped rollers (TSRRAR), a new flexible forming technology, was investigated to effortlessly produce 3D surface parts. Numerical simulation and experimental analysis mainly include data at four values of the difference in axial radius of roller (−2, 2, 6 and 10 mm) to explore this technology's forming ability. It was demonstrated that various shapes could be obtained only based on one group of rollers. The maximum resultant force decreased from 3.07 to 2.21 KN, and the required maximum compression rate from 4.22 to 2.48 % with the same longitudinal curvature radius (179 mm) to be obtained. Therefore, the forming difficulty can be reduced by selecting the difference in axial radius of roller. [ABSTRACT FROM AUTHOR]

Effective sequencing and scheduling of material handling systems (MHSs) have a major impact on the productivity of a manufacturing system. Since the main function of a MHS is to supply the right materials at the right locations at the right time, the design of automated guided vehicles (AGVs) fleet-oriented, distributed and scalability-robust control policies ensuring deadlock-free operations is of crucial importance. In this context, a given design of a flexible manufacturing system (FMS) where vehicles serve workstations located along different modes of cyclic guided paths in a 3D environment composed of rails/lifts/hoists is considered. Furthermore, fuzzy processing time constraints on transportation operations, a production flows scheduling problem subject to an assumed set of constraints imposed by admissible production routes and schedules of AGV fleet in a given MHS are considered. Since this type of problem can be treated as a fuzzy constraint satisfaction problem, the main objective is to provide analytical formulas enabling the avoidance of time-consuming computer-simulation-based calculations of AGV fleet schedules, as well as vehicles deadlock and collisions, while keeping the throughput at the maximum achievable level. Results of computational experiments assessing the scalability of the proposed method are presented as well. [ABSTRACT FROM AUTHOR]

In this article, we present the development of a simple multiagent-based system for the control of a flexible manufacturing system. We followed the stages of a methodology specially conceived for the development of agent-based system, which is an integration of the classical methodology for agent-oriented analysis and design Gaia, and AUML (Agent-Unified Modeling Language). We adopted as study case the CIMUBB Laboratory at the University of Bio-Bio, which has a flexible manufacturing system including three flexible manufacturing cells interconnected by a conveyor belt. In the analysis stage, we identified roles involved, and we design models representing roles and protocols. In the design stage, we applied Gaia agent, services, and acquaintance models from Gaia, and we complemented with AUML as the adopted methodology suggests. With the developed models, we constructed a fully functional system where each agent was built as an independent process tree. Agents communicate by passing messages through the Ethernet network with socket interfaces. Various tests executed in our laboratory scale manufacturing system show the effectiveness of our implementation. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This investigation aims at predicting the transient performance measures of a machining system comprising of M operating units and multi types of warm standbys under the care of a single unreliable server. To deal with more realistic situations, the concepts of imperfect recovery and reboot delay are also incorporated. The queue size distribution is obtained by using the matrix method. The explicit expressions for various performance measures such as reliability, throughput, expected number of failed units in the system, failure frequency of the server, etc. are obtained. A numerical illustration is presented to demonstrate the practical application of the proposed model in the flexible manufacturing systems. [ABSTRACT FROM AUTHOR]