Production Flow Line Research Articles

Incorporating design improvement with effective evaluation using the Manufacturing System Design Decomposition (MSDD)

Abstract The definition of system metrics is crucial to determine if a manufacturing system design is truly effective because inappropriate metrics can lead to ineffective or improperly-focused system improvements. This research highlights the importance of measuring the system design that contributes to system effectiveness. The authors propose the use of a Manufacturing System Design Evaluation Tool to assess the effectiveness of the design of manufacturing systems as a whole. The tool was developed based on the Manufacturing System Design Decomposition. The Manufacturing System Design Evaluation Tool measures how well a system is designed based on the requirements outlined in the Manufacturing System Design Decomposition. System effectiveness is evaluated based on six physical manufacturing system configurations: the Departmental or Job Shop Layout, Departments Arranged by Product Flow (sometimes called a Flow Shop), Assembly or Transfer Line, Pseudo-Cell (a cell that is called a cell but does not meet all of the requirements of a cell), individual Assembly or Machining Cells (but not yet integrated as a system), and a Linked-Cell Manufacturing System for all aspects of a production value stream. The Linked-Cell Manufacturing System is considered to be the physical configuration that represents the highest level of manufacturing system design requirements achievement. In addition, the siginificance of implementing one physical element relative to achieving the requirements of the overall manufacturing system design may be evaluated. With this feedback, management is able to identify elements of the system design that need improvement and additional resources. The proposed Manufacturing System Design Evaluation Tool may be applied to evaluate most repetitive, discrete-part manufacturing systems.

Subsea Production Optimization in Field BC-10 Offshore Brazil

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 26220, “BC-10: Optimizing Subsea Production,” by N.C. Sleight and N. Oliveira, Shell, prepared for the 2015 Offshore Technology Conference Brasil, Rio de Janeiro, 27–29 October. The paper has not been peer reviewed. The BC-10 asset, located in deep water offshore Brazil, produces heavy oil in the range of 16 to 24 °API. Mudline caisson separators with electrical submersible pumps (ESPs) are used to process fluids from multiple wells and boost them to the receiving floating production, storage, and offloading (FPSO) vessel. There are significant flow-assurance challenges in operating the asset. In this paper, two examples of production optimization for this field will be provided (further examples are available in the complete paper). BC-10 BC-10’s production comes from four fields located in water depths ranging from 1650 to 1920 m and is dependent on artificial lift. This summary focuses on optimizations involving the Ostra field. The subsea architecture that enabled the development of these separate reservoirs consists of multiple drill centers coupled to production manifolds. Manifolds are routed to caisson ESPs. These caisson ESPs will henceforth be referred to as MOBOs (derived from the Portuguese acronym for pump-boosting module). To minimize equipment costs, each field has only two production flowlines routed to the host: one is for production, and the second is for hot-oil displacement and production. In the case of Ostra, a third riser for gas separated subsea is also present. This design reduces the number of risers required. In line with this philosophy, there are only three oil-production trains and one gas separator on the host. Ostra Field Ostra consists of seven producer wells, with production collected by two manifolds and routed through two 8-in. intrafield flowlines to the artificial-lift manifold (ALM), which houses four caisson separator MOBOs. The operating philosophy is to run three units out of four, leaving the fourth unit as a standby in case of MOBO failure. Because the ALM is not located with permanent vertical access, MOBO interventions require the use of a rig capable of pulling the 140-t unit to surface. For this reason, having an installed spare is critical. The production manifolds allow one of two routings per well, which allows a flowline to be aligned to one, two, or more MOBOs; full bypass of the MOBO; and routing of hot oil for MOBO startup and planned shutdown from the surface by a dedicated choke. It is also possible to allow the 4.5-in. hot-oil supply line to be used for production. The 8-in. gas line features a common choke on the ALM to control backpressure on the MOBOs and a surface choke at the FPSO vessel as a second means of control. In practice, to avoid a well trip causing a rapid loss of MOBO pressures (with corresponding well-rate increases), the subsea-gas-line choke is used only in special circumstances, with daily control being performed by use of the topside boarding choke, which allows a much larger gas-storage volume and hence limits rapid pressure transients. The Ostra field has seen good pressure support through the first 5 years of operation because of a strong supporting aquifer, and it currently produces 60,000 to 70,000 B/D gross. Gas disposal was performed through an injection well deeper in the Ostra aquifer while gas export was commissioned.

Variability modelling and balancing of stochastic assembly lines

In a production flow line with stochastic environment, variability affects the system performance. These stochastic nature of real-world processes have been classified in three types: arrival, service and departure process variability. So far, only service process – or task time – variation has been considered in assembly line (AL) balancing studies. In this study, both service and flow process variations are modelled along with AL balancing problem. The best task assignment to stations is sought to achieve the maximal production. A novel approach which consists of queueing networks and constraint programming (CP) has been developed. Initially, the theoretical base for the usage of queueing models in the evaluation of AL performance has been established. In this context, a diffusion approximation is utilised to evaluate the performance of the line and to model the variability relations between the work stations. Subsequently, CP approach is employed to obtain the optimal task assignments to the stations. To assess the effectiveness of the proposed procedure, the results are compared to simulation. Results show that, the procedure is an effective solution method to measure the performance of stochastic ALs and achieve the optimal balance.

Development of an application for balancing product flow lines through genetic algorithms

When defining the layout for a production line, it is necessary to assign tasks to workstations, so that the work is performed in a feasible sequence and approximately equal amounts of time are needed at each workstation, a process called line balancing. Therefore, the need for balancing production lines involves the distribution of sequential activities for jobs in order to allow high labour and equipment utilisation and minimise the idle time. Line balancing problems are complex to treat, being used distinct methodologies to perform it. This paper describes an application for line balancing using two genetic algorithms (the first obtains solutions to the problem and the second optimises those solutions), associated with a graphical interface for the problem data input and visualisation of results. Results demonstrate advantages over heuristic methods as it is possible to obtain more than one solution and it is more practical to use the developed application.

Studying the rheological properties and the influence of drag reduction on a waxy crude oil in pipeline flow

The present work studies the effect of a commercially type of drag reducing agent on the crude oil production flow lines located in the Egyptian western desert (Fagour field) and owned by Khalda Petroleum Company. The drag reducing agent used in this study is a high molecular weight poly alpha olefin prepared by emulsion polymerization technique and supplied under trade name of LP-111. The results showed that this drag reducing agent (DRA) has great effects on the pressure drop and fanning factor. After the field application of 60ppm of the DRA, the pressure drop was decreased by 36% at the pipeline capacity of 18,804bbl/day. The fanning number and shear stress were decreased by the same percentage of 47%. The capacity of production line can be increased by 38% all over the two pipeline section due to the great reduction of pressure drop.The rheological behaviors of tested waxy crude oil were studied at different temperatures (varies from 67 to 102°F) and different DRA concentrations (10, 20, 30, 40, and 50ppm). The results showed that at all constant DRA concentrations, the viscosity highly decreased until 80°F (above pour point by 15°F). However, by increasing the DRA concentration, the viscosity is increased at temperatures lower than 80°F. This is because the DRA is a high molecular weight polymer which participates in increasing viscosity by increasing its concentration. After 80°F, the DRA concentration has an insignificant effect on viscosity. So the effect of the DRA is not in reducing viscosity but mainly in reducing the degree of turbulence energy. The field studies were performed at a normal temperature of tested pipeline sections (100°F). The tested DRA has an improving effect on reducing the pressure drop of pipeline which leads to reduction in crude oil pumping energy or an increase in the pipeline capacity with a high efficiency of the DRA.

Genetic Modelling for Selecting Optimal Machine Configurations in Reconfigurable Manufacturing System

Selecting the optimum machine configurations for any product flow line has direct implications on the system performance. In the present paper, an evolutionary algorithm based methodology has been proposed for optimal machine assignment based on a weighted objective function. The objective function includes reliability, cost, production time and operational capability as performance indicators. The methodology demonstrates how several performance parameters can be dealt with, in order to select optimal machine configurations for distinct stages across any serial product flow line. The proposed approach can possibly be employed in handling the RMS performance issues and optimal trade-offs among the various performance parameters.

Design of a Heuristic for Balancing a Multi-Stage Production Flow Line

A production flow line balancing problem for automotive industry has been studied. A batch of an end item is produced by transforming sheet metals into parts at different manufacturing stages followed by assembly operations. The forming operations of the sheet metals into various parts and their assembly works are illustrated through 22 different tasks. Some of the tasks have the processing times greater than the takt time and are categorized as extra-long tasks. Attempts were made to solve this intricate line balancing problem by adopting the Ranked Positional Weight (RPW) method. But the solution given by the RPW model loses its exactitude due to the presence of the extra-long tasks. In this research a heuristic approach based on RPW is developed through which the problem has been resolved in an efficient and effective manner and hence the proposed heuristic is deemed to be capable of balancing production lines having such extra-long tasks.

Differential scanning calorimetry and optical photo microscopy examination for the analysis of failure of fusion bonded powder epoxy internal coating

An investigation was conducted to find out the reason behind the failure of the powder epoxy internal coating from production flow line of Large Scale Pilot Project (LSP) from an oil exploration in Kuwait. The internal coating was completely detached and peeled out in the form of curling from the substrate, and causing the production flow line to be plugged with the deposit of paint debris. The production operation of oil supply from the LSP well was stopped due to this failure and the pipeline was replaced. Multiple field techniques and laboratory approaches were used to find out the reason behind the coating failure. The research work involved utilizing the analysis of the surface carbon steel substrate with new epoxy coated sample as compared to the failed one using differential scanning calorimetry (DSC) and optical and photomicroscope examination. The overall results indicated that the failure was due to the combined effects of the improperly cured coating as determined by differences in the glass transition temperature (Tg), and differential thermal expansion properties between the steel tube and coating causing shrinkage stresses resulting in disbonded coating. This was enhanced by the expansion of corrosion oxide products as a sequence of ineffective substrate pre-treatment.

Performance Analysis of Exponential Multi-Server Production Lines with Fluid Flow and Finite Buffers

This article presents an approximation method for fluid flow production lines with multi-server workstations and finite buffers. Each workstation consists of parallel identical servers, which are subject to operation-dependent failures with exponentially distributed uptimes and downtimes. The proposed method decomposes the production line into single-buffer subsystems, each described by a continuous state Markov process, the parameters of which are determined iteratively. The approximation method is appropriate for the analysis of longer production lines, able to accurately estimate performance characteristics (e.g., throughput and mean buffer content), and shown to perform well on a large test set.

Mathematical Model of Productivity with Reliability and Losses Parameters for Serial Structure Linear Production Automated Flow Line: A Simulation Analysis

Industrial automated production flow line focus on productivity assessment and analysis since it present an important indicator of company profit and performance. Serial structure of production automated flow line widely implement in automated production sector for mass production. High accuracy yield of mathematical model of productivity is important for forecast work to increase the profits of company. This paper presents application of Witness software simulation for mathematical model of productivity with different reliability level of workstations and mechanisms, bottleneck machining time, and defected parts parameters for serial structure automated to validate this mathematical model which produce higher accuracy forecast result compare to current mathematical model of productivity which not consider few of productivity losses parameters. Validation through software simulation for mathematical model is important since there is lack of simulation for this model in current research for mathematical model. The simulation result for model is show higher accuracy which near to actual simulation productivity and the current mathematical model is replace by mathematical model with different reliability level for productivity forecast in academic and industries due to accuracy reason.

Capacity augmentation with VSM methodology for lean manufacturing

Purpose – The purpose of this study is to enhance the output of a manufacturing set-up in phases, by identifying the wastages in the existing line and, thereby, reducing them. Design/methodology/approach – Feasibility checking and optimization of capacity enhancement of a processing line have been discussed. Value stream mapping (VSM) methodology has been used as a data-driven decision-making tool to identify the constraints in the current state and subsequent states. The future state has been achieved in stages using VSM tool of lean manufacturing, coupled with the management philosophy of Theory of Constraints. An example of an Indian company has been added to demonstrate the suitability of the approach. Findings – The proposed approach addresses an important issue of phased increase in customer demand and the process of accommodating it through multi-phased maneuvering of productive capacity at constraint points instead of enhancing the capacity at one go. The underlying problem of capacity enhancement has been addressed using lean principles and the optimum feasible option has been designed so that the increase in cost is minimized along with satisfying the stepwise increase in demand. Research limitations/implications – This research work is applicable to the manufacturing sector. Originality/value – This paper proposes a methodology for phased upgrading of a production flow-line in keeping with a steady increase in customer demand. Here, VSM has been applied in a phased manner, and the constraint in the current state as well as in each subsequent phase has been identified and removed.

Solving a new multi-objective multi-route flexible flow line problem by multi-objective particle swarm optimization and NSGA-II

Mass production, meeting the increasing demands of the customers is a necessity. Such a production is mainly dependent on a factory manufacturing called flow line production. This paper deals with special type of production by the name of flexible manufacturing system, assuming the presence of multi processors in each station of a multi-station arrangement. The model debated in the paper possesses three objective functions, the first of which attempts to minimize the weighted delays. The second objective function tries to minimize the capital for the purchase of the processors at stations and the third objective function minimizes the capital dedicated to select the optimum processing route of parts. For the validation of the mathematical model, use has been made of NSAGAII and MOPSO approaches.

선형 Roll-CMP에서 공정변수에 관한 통계적 분석

Nowadays, most micro-patterns are manufactured during flow line production. However, a con- ventional rotary chemical mechanical polishing (CMP) system has a limited throughput for the fabrication of large and flexible electronics. To overcome this problem, we propose a novel linear roll-CMP system for the pla- narization of large-area electronics. In this paper, we present a statistical analysis on the linear roll-CMP process of copper-clad laminate (CCL) to determine the impacts of process parameters on the material removal rate (MRR) and its non-uniformity (NU). In the linear roll-CMP process, process parameters such as the slurry flow rate, roll speed, table feed rate, and down force affect the MRR and NU. To determine the polishing char- acteristics of roll-CMP, we use Taguchi's orthogonal array L16 (44) for the experimental design and F-values obtained by the analysis of variance (ANOVA). We investigate the signal-to-noise (S/N) ratio to identify the prominent control parameters. The higher is better for the MRR and lower is better for the NU were selected for obtaining optimum CMP performance characteristics. The experimental and statistical results indicate that the down force and roll speed mainly affect the MRR and the down force and table feed rate determine the NU in the linear roll-CMP process. However, over 186.3 N of down force deteriorates the NU because of the bending of substrate. Roll speed has little relationship to the NU and the table feed rate does not impact on the MRR. This study provides information on the design parameter of roll-CMP machine and process optimization. Keywordslinear roll-CMP (선형 롤-화학기계적 연마), taguchi method (다구찌법), material removal rate (연마율), non-uniformity (불균일도)

The Study of Buffer Allocation Problem in Complex Production Line

This paper studies the problem of allocating buffers in stochastic production flow lines with product travel time. We build a model that decomposes the production line into the S-B-S (Station-Buffer-Station) subsystems, and use queueing theory to aggregate the subsystems. Experiments are designed for both balanced and unbalanced production lines, and with the computational results, some general rules for the buffer allocation problem are proposed. DOI : http://dx.doi.org/10.11591/telkomnika.v12i3.4520 Full Text: PDF

Adaptive simulations in T-shape tube hydroforming with different outlet diameters

A successful tube hydroforming process depends largely on the loading paths for controlling the relationship between the internal pressure, axial feeding and the counter punch. The objective of this article is to propose an adaptive control algorithm to determine appropriate loading paths in T-shaped protrusion hydroforming with different outlet diameters. The finite element analysis is used to simulate the flow pattern of the tube during tube hydroforming process. The analytical flow line net configuration of the tube is utilized to determine the speed ratio of the counter punch to the axial feeding at the protrusion stage. Appropriate loading paths for different outlet diameters are determined using the proposed adaptive control algorithm. Different pressurization profiles are used in the tube hydroforming experiments. Experimental results show that a sound product is obtained using the pressurization profile determined by the proposed adaptive simulation algorithm. From the comparisons of the product shape and flow line net configurations between the analytical and experimental values, the validity of the proposed control algorithms is verified.

Prediction of machine reconfigurability using artificial neural network for a reconfigurable serial product flow line

Reconfigurable machines (RMs) are considered to be one of the vital elements of modern manufacturing systems like reconfigurable manufacturing systems (RMSs). These machines offered customised flexibility in terms of capacity and functionality. Reconfigurable machines are assembled using some basic/essential modules and auxiliary modules. The RMTs can be reconfigured into several other configurations for variable functionality and capacity by keeping its base modules and just adding/removing or adjusting the auxiliary modules. Measuring machine reconfigurability may be considered as one of the important challenge in assessing the performance of these manufacturing systems. In the present paper, an artificial neural network model has been proposed for quantitative assessment of reconfigurability values of RMs on the product flow line. The data is generated using a developed mathematical model based on multi attribute utility theory. The ANN predictive model could thus provide a flexible and objective framework for manufacturers to evaluate reconfigurability of machines for a given product flow line. The developed approach has been demonstrated using a multi stage serial reconfigurable product flow line.

Optimisation of process plans in reconfigurable manufacturing systems using ant colony technique

A reconfigurable manufacturing systems (RMS) is designed around part family products because of its customised flexibility. System scalability and machine adaptability to new products makes RMS preferable in comparison to other manufacturing systems. The modification of RMS system can be done both physically by changing layout, machines and material handling devices and logically by changing route, schedule, planning, etc. This paper aims at finding optimal process plans of a single product flow-line RMS using ant colony optimisation approach consist of two phases. In the first phase, priority-based encoding technique is applied to find feasible operation clusters and the second phase uses ant colony technique for minimising the total cost of the RMS. A case study illustrates the proposed approach by developing a tool box in MATLAB software.

English

Reconfigurable manufacturing systems are recognized as next generation manufacturing systems capable of providing the exact functionality and capacity as and when required. The reconfiguration of the system depends upon the ease with which any machine can be added, removed or re-adjusted for upcoming configuration from any initial or outgoing configuration. The efforts required while changing any existing configuration to a new configuration have serious implications on the cost aspect as well. The complexity and economics involved in changing one configuration to another depend on the existing initial configuration and the new upcoming configuration required for subsequent production of part families. In the present paper, based on the different types of effort associated with the reconfiguration process, a new indicator of performance termed as “Service Level” is proposed. The proposed indicator is modeled for a multipart reconfigurable manufacturing system. The proposed methodology is demonstrated using a numerical example. The values obtained for service levels while switching from one configuration to another were calculated for a serial product flow line. Some of the important implications regarding service level evaluation and implementation are finally discussed.

The Study of Buffer Allocation with Travel Time in Stochastic Production Flow Line

This paper studies the problem of allocating buffers in stochastic production flow lines with product travel time. We build a model that decomposes the production line into the S-B-S (Station-Buffer-Station) subsystems, and use queueing theory to aggregate the subsystems. Experiments are designed for both balanced and unbalanced production lines, and with the computational results, some general rules for the buffer allocation problem are proposed.

New model of the sintering process

Dimensional analysis is used to construct a new mathematical model that establishes a closer relationship between the unit productivity of a sintering machine and the parameters of the sintering operation. An analysis is performed to determine how the unit productivity of the sintering machine is affected by the total gasdynamic resistance of the bed, the coarseness of the material being sintered, the unit load complex, and the duration of the sintering operation. gasdynamic resistance of the bed, duration of the sintering operation, height of the bed, bulk density of the charge, coarseness of the material. Modern sinter plants are a complex system of different types of equipment that operate in different regimes and have different technological functions. The growth of sinter production is being accompanied by intensification of the auxiliary and production operations that are performed. The overall increase in sinter output and a tightening of requirements on sin- ter quality and the ability of the various operations to be performed under flow-line production conditions are creating a good opportunity for the broad introduction of automated monitoring and control equipment. Such equipment should be developed by economics- and mathematics-based methods and should maximize the productivity of the sintering machine and make the most efficient possible use of the raw materials, fuel, and capital expenditures while ensuring a certain level of product qual- ity and protecting the environment. Automated systems developed to control sinter production should also improve the orga- nization of production operations and provide for real-time control over the production process. One tool that can be used to automate sinter production is mathematical modeling. The mathematical models which are constructed can be employed to create suitable control algorithms that can work with existing hardware and software. The unit productivity of a sintering machine is one quantitative criterion of the efficiency of the sintering process. The following are the main factors that affect the efficiency of this process: the coarseness and material composition of the material being sintered; the coarseness and quantity of fuel supplied to the charge; the charge's moisture content; the coarse- ness and quantity of undersized sinter; the coarseness and quantities of the various additives that are used; the height of the bed of charge materials on the sintering machine; the vacuum created by the exhauster; the efficiency with which the charge is mixed; the character of the charging operation and the associated segregation of different charge components; the presence of different "sublayers" in the bed of charge materials; the initial temperature of the charge. The studies (1, 2) presented a mathematical model that determines the dependence of the unit productivity of a sin- tering machine W (kg/(m 2 ·sec)) on the total gasdynamic resistance of the charge bed p (kg/(sec 2 ·m), sintering time τ (sec), bed height h (m), the bulk density of the charge ρ (kg/m 3 ), and the coarseness of the material being sintered. The last param- eter is expressed through the equivalent diameter of the balled charge d (m). The model has the form