A Simulation-Based Bottleneck Identification Approach for Complex Mining Production Systems

Systems approaches for the design of sustainable agro-ecosystems

The aim of this paper is to present a study that deals with the problem of oversized boulders in a mine production system. This work was performed to study and analyze the disturbances caused by oversized boulders and estimate their impact on the production system at the LKAB Kiruna Iron Ore Mine, Kiruna (KIOM). The results from this study show that by elimination of oversized boulders from the production process, the production capacity and system utilization of a mine like KIOM can be considerably improved.

The article examines the institutional foundations of managing renewable energy generation facilities in the agricultural sector. The relevance of the study is determined by the transformation of modern energy systems, the development of decentralized generation, and the growing role of the agricultural sector in shaping energy flows. The object of the study is the process of managing renewable generation facilities within the structure of agricultural production systems. The subject of the research comprises institutional mechanisms and the organizational and economic foundations governing the functioning of these energy assets. The methodological basis of the study includes the principles of institutional economics, the systemic approach, and the theory of management of production systems. The research applies methods of theoretical generalization, systemic and structural-functional analysis, as well as logical modelling. The article substantiates the institutional nature of managing renewable generation facilities in the agricultural sector and identifies the specific features of integrating energy-generating facilities into the production and economic system of agricultural enterprises. A conceptual model for the institutionalization of renewable generation management is proposed, based on the interaction of production, energy, and institutional-market contours of the functioning of energy systems. A multi-level institutional architecture for managing these facilities is identified, encompassing macro, meso-, and microeconomic levels of regulation. The obtained results deepen the theoretical foundations of renewable energy development in the agricultural sector and may be used in designing mechanisms for managing energy assets of agricultural enterprises.

Part V deals with the simultaneous operational planning and maintenance of the utility and production systems of a process industry. In this chapter, a general optimization framework is presented with the main purpose of reducing the energy needs and material resources utilization of the overall system. The proposed mathematical model focuses mainly on the utility system and considers for the utility units: (i) unit commitment constraints, (ii) performance degradation and recovery, (iii) different types of cleaning tasks (online or offline, and fixed or flexible time window), (iv) alternative options for cleaning tasks in terms of associated durations, cleaning resources requirements and costs, and (v) constrained availability of resources for cleaning operations. The optimization function includes the operating costs for utility and production systems, cleaning costs for utility systems, and energy consumption costs. Several industrial-inspired case studies are presented in order to highlight the applicability and the significant benefits of the proposed approach. In particular, in comparison with the traditional sequential planning approach for production and utility systems, the proposed integrated approach can achieve considerable reductions in startup/shutdown and cleaning costs, and most importantly in utilities purchases, as it is shown in one of the case studies.

This study is based on in-depth empirical data taken, as an outside-observer, from a medium-size enterprise. It provides hard evidence of the new non-financial Keys Performance Indicators (KPIs)' efficiency to evaluate a production system's (PS) performance. It has been proven that the use of only the internal performance measurement system (PMS) is not enough as a significant measurement. The need of an external performance measurement (PM) is very important. As will be demonstrated the combination between the new non-financial PMSs and the systemic approach; a vital tool to support the continuous improvement of a PS's performance.

A new Simulation-Based Approach in the Design of Manufacturing Systems and Real-Time Decision Making

The current trend towards restructuring to improve the standards and efficiency of public services in sub-Saharan Africa, within the framework of economic structural adjustment programmes, has stimulated debates and proposals regarding veterinary services in the region. Such debates sometimes neglect the fact that a number of different animal production systems may coexist within a single economy. The authors review the concept of veterinary services delivery systems and examine this concept in the context of animal production systems, concluding that different delivery systems may be required to cater for different production systems. Planners and policy makers are urged to ensure that advocated changes are compatible with the existing animal production systems. This systems approach may be applied in considering various aspects of veterinary services, including animal health care delivery, animal health education and training, research, outreach work and financing.

Diagnosis of many future adhesion problems will be based on current knowledge, reported at this symposium. But, prognosis permitting a decisive choice of materials and of methods in a specific situation, is not always possible. Considering the broad range of disciplines involved, a systems approach is proposed to reach a logical overlap between theory and practice. Four systems will be discussed in some detail. The established concepts of adhesive strength in mechanical systems should be amended by a consideration of fracture energies in terms of a macroscopic, continuum model, followed by a discussion of microscopic and molecular structures. Interface systems are common to both adhesion science and tribology. Recent work on the nature of static friction and of boundary lubrication has contributed to the understanding of interface adhesion. Among the operational variables evaluated in production systems the ‘adhesionable’ properties of adherends are badly in need of closer examination. In biological systems the strength and toughness of calciferous tissues should be compared with the corresponding properties of interlocking adhesives.

Reducing preharvest food losses in spinach with the implementation of high tunnels

Given the need for agricultural system management under sustainability principles, identification and quantification of the landscape structure surrounding production systems is a tool that allows farmers to make their agroecological transition processes more appropriate. An ACI with eight indicators was proposed for farm assessment. This ACI is focused on functional connectivity both at farm and landscape levels. Two Colombian farms with different connectivity characteristics were evaluated under the index. Tosoly presented a stronger ecological structure and higher connectivity and diversity. Villa Alicia showed a weak ecological structure and low connectivity and complexity. From a systemic approach, the ACI allows an analysis of landscape structural conditions that promote ecological functions of pollination and biological controllers. With landscape structural conditions, it is possible to analyze the quantity and quality of the habitat for designing agroecological transition programs focused on obtaining productive agroecosystems that simultaneously comply with conservation strategies.

Farm biogas production in organic agriculture: System implications

A computer program has been developed to simulate the total facilities, substructure, weight, area and cost parameters of offshore oil and gas production platforms. This program was developed as a Joint Industry Project with 19 major oil companies. The program will perform the following activities from approximately 2.50 'Management Decisions'.automatic heat and material balances for offshore production facilities including a specified crude vapor pressure product and gas lift recycleutility balancesphysical sizing of all major equipmentdry and operating weights of all major equipmentdry and operating weights of all bulks by category (including pipe, valves, fittings, local instrumentation, electrical items, equipment support steel, pipe supports, insulation and painting)weight and area estimate for 6 different substructures (fixed and floating types)installed cost estimate for the complete production related facility and substructure. This program, which was developed for feasibility study applications to field developments, is the natural progression of a systems approach to estimating the weight and area impact of important management decisions. The data collected to provide input for the systems came from historical installed parameters, extensive study work with bulks, and supplier information. The computer program and its data base are viewed as important economic study tools to rapidly review the relative impact of basic design decisions. Very often design decisions for oil or gas field development are based upon limited information and can prove costly to rectify. With the use of this program, envelopes of field development parameters may be rapidly developed with parametric cases to provide - management with better information for their design decisions. Examples of the results of the program will be presented, which relate the impact of various elemental management decisions. Introduction The latitude of production variables and system requirements for offshore facilities is wide. Often production platform cost estimates for feasibility studies cannot rely upon past historical information. Because initial information may be sparse, many assumptions have to be made and large contingencies may be added to the development costs. To reduce the magnitude of the cost contingencies, a computer simulation of an offshore production facility has been developed to perform economic estimates based upon detailed scoping of equipment and weight analysis. The first general 'combined services platform' program was developed as a Joint Industry Project with 19 major oil companies. Other programs have been completed and are under development for more specific processing needs. Figure 1 illustrates the linear flow of information from the input 'Management Decisions' to the process simulator and related systems routines. The program will perform a process simulation of the production facilities, size all of the required equipment, estimate the dry and operating weight of all major equipment and bulks, and perform a cost estimate for the topside facilities and supporting substructure. The basic premise of this approach is that accurate scoping and sizing of major equipment is the key to good offshore weight, space, and cost estimates. The method uses a pyramid-type systems approach in which every item of equipment is accounted for and grouped into several systems fully describing the facilities.

The Relevance of Systems Methodologies in the Development of Organizational Systems The relationship between systems development and systems methodologies is discussed in this paper. As the measure of system development on the macro level, Gross Domestic Product (GDP) is assumed to be the consequence of systems Research and Development (R&D), which is estimated indirectly by the number of published articles in the last 40 years. It was supposed that profit and governmental organizations are systems comprised of Production, Management and Information Systems (IS), and that their quality performance is related with its income generation, which in the future would impact the overall GDP of a country. Under such view, we also assume that such organizational processes are qualitatively improved by the application of knowledge generated by research publications, and in this study, we research for the specific case of the Systems Approach (SA), Systems Engineering (SE), Operational Research (OR), Information Systems Development (ISD) and Simulation, as the research topics for coping with organizational improvement. We looked for the articles containing the afore-mentioned variables as topic keywords, which indicate sufficient correlations with GDP and carrying information on sustainable development. We found a positive trend in the evolution of research methodologies, such as SE, ISD and OR, towards a Systems Approach and Simulation as a holistic methodology. As a result, we have proved the dynamic hypothesis of a high correlation between GDP of Top 10 + Slovenia and R&D expressed by the above-mentioned variables.

Aim. The presented study aims to examine the specific features as well as organizational and technical aspects of production logistics, taking into account its potential for using digital technologies.Tasks. The authors consider the essence, purpose, and goals of production logistics; analyze major logistics systems used in production logistics; assess the prospects for using digital technologies in this sphere.Methods. This study uses the methodology of strategic and logistics management, the systems approach, life cycle theory, general scientific methods of generalization, comparative, retrospective, and structural-functional analysis.Results. The production and logistics systems of a company are considered as equivalent elements in the context of managing material flows in internal and external supply chains and achieving the company’s operational and development goals. In this regard, production logistics is shown as part of both logistics and production, which affects its organization and architecture. Under modern conditions, an approach based on certain data is widely used in production logistics. It requires active introduction of digital technologies in production logistics, the purpose of which is not to achieve technical or organizational perfection of business processes, but to select technologies from the perspective of creating additional value.Conclusions. In the course of the study, three categories of activities associated with production logistics are identified. For each of these categories, the prospects and recommended classification of digital technologies are defined. Particular emphasis is placed on improving the quality and efficiency of data use. According to the authors, all information systems and digital technologies used in production logistics should be highly reliable. Thus, introduction of any new technologies in production logistics requires careful consideration. Regardless of the type of technology, a systems approach to the organization and development of production logistics is a prerequisite for the efficient operation of the company as a whole.

Intelligent distributed and supervised flow control methodology for production systems