Jaroslava Janeková

ASSESSMENT OF THE ECONOMIC EFFICIENCY OF THE MODERNIZATION OF CRUSHED STONE MANUFACTURING PROCESS: CASE STUDY

The aim of the paper is to evaluate the economic efficiency of the proposed modernization of the production process of crushed stone in the quarry and to decide whether to accept it or reject it. The project is assessed in a complex way. Profitability is evaluated using Net Present Value (NPV) and Profitability Index (PI), liquidity by means of Discounted Payback Period (DPP). The risk associated with the respective investment is assessed using a probabilistic method Monte Carlo simulation.

Designing Simulation Model of the Production Operation for Further Decision Making

Simulation as a decision making method through its software is a supportive tool for analysis of a material flow, and it is appropriate when a performance of complex systems have to be evaluated, designed and optimized. As the behavior of complex systems is hardly predictable, simulating the existing systems’ performance is helpful in order to gain results of system performance before applying changes in a real system. A change that appears to be a best solution might, after calculation and analysis of its consequences, prove as a wrong direction lead. The more accurately is the model built, the more real results are being achieved. Decisions about the performance improvement might be intuitive as what-if analysis, or achieved by process redesign and improvement methods as Theory of Constraints, Lean Manufacturing, Six Sigma Method, some of them with slight changes in a single processes following Kaizen principles.

Application of Modelling and Simulation in the Selection of Production Lines

Production lines are complex mechatronic systems which have in their structure mechanical, electronic, control and software subsystems. The complexity of these systems is identified for mass production of paper napkins. The aim is to decide on the choice of the production line in terms of ensuring growth of value of the business and satisfaction of customers needs. The decision making process is carried out in steps of formulating the investment problem, technical features of the project, economic evaluation of the project based on a financial model in Microsoft Excel and analysis of project risks utilizing Monte Carlo simulations in the Crystal Ball system.

Laboratory Experiment of New Cutting Materials in Milling Processes

The development of manufacturing technology is mostly given by economics, environmental trends and the development of cutting materials and machine tools. Manufacturing is a significant part of the worldwide economy. Machining (material removal processes) represents major part of production costs. This paper yield inquiries into the hard and precise milling with a focus on force effects in experimental machining, tool wear and final surface qualities (roughness, micro hardness). The precision machining of hardened steel differs from conventional machining in terms of the hardness of the workpiece materials and the cutting tool materials that are required. Hard materials are characterized by high hardness (> 45 HRC) and abrasiveness. Machining processes require cutting tools of much higher hardness and also higher resistance of the abrasive wear. Recently developed cubic boron nitride (CBN) and coated sintered carbides cutting tools are considered to have the ability of cutting such as steel. CBN cutting tools show good performance during machining of the hardened steel because of their hot hardness and good fracture toughness.

Logistic of Building Simulation Model of Healthcare Facility for Further Performance Management – Case Study

Logistics, as a scientific discipline, used to be oriented till lately on distribution of finished products from producer site to consumer sector, and this fact has reflected even in modeling and simulation approach. Simulation models of Healthcare Services, and generally services, can be considered as innovative procedures and till lately were not as widely described as for example typical material flow in manufacture. However, base knowledge that inheres in production simulation models can be applied at building of services simulation models.

Failure prediction by means of cepstral analysis and coherence function between thrust force and torque signals

Requirements for flexible manufacturing have been increasing in the last years. In order to insure effective operation of expansive manufacturing equipment, which has to run automatically and unattended, tool monitoring is important. Therefore, the essential problem to be overcome to achieve the full potential of unmanned machining is the development of effective and reliable sensors system to monitor the process and corrective actions in case abnormal operation. The ultimate goal of the development of such production equipment is to enhance the overall economic of the manufacturing process. Even when there are at present many monitoring systems commercially available in the market for turning processes, serious difficulties still remain to be solved to apply monitoring systems successfully in machining centers. Being these difficulties mainly related with the limited accessibility to the rotating tool for sensing purposes in tool driven machining processes. Therefore, the primary objective of this paper assess the feasibility of using force signal analysis as means for monitoring tool condition in drilling.