Cycle Time Reduction Research Articles

Semi-batch industrial process of nitriles production: Dynamic simulation and validation

A semi-batch reactor is used to produce nitriles by reacting fatty acids and ammonia. Despite it is an old chemical process and many patents are available in the literature, its mathematical model was not developed until now. This process comprises a semi-batch reactor with recycle, which makes the numerical solution a challenge to face. In this paper, the entire process has been computer simulated for the very first time. Aspen Plus software was used to find the initial condition for the set of differential algebraic equations, which will be solved by Aspen Plus Dynamics, the key tool to ensure that the entire batch cycle could be properly programmed. Besides that, PI controllers were implemented to guarantee normal and safety operation of the process evaluated, in other words, controllers performed well in tracking pressure and composition profiles, target conversion for the desired product and level behavior. The simulated results were validated with industrial data and opportunities for improving the process were evaluated. The main result was a reduction in batch cycle time for around 40 min.

Using Rapid Cycle Improvement (Plan, Do, Study, Act) to Design a Scalable Appointment Scheduling System for Complex Oncology Clinical Trials at an Academic Cancer Center.

This study's purpose was to optimize the efficiency of and to design a scalable research scheduling team to meet the growing demands of an academic cancer center with increasing clinical trial accruals. The Plan, Do, Study, Act improvement methodology was deployed to increase the efficiency of research scheduling, to reduce non-value-added (NVA) activities, and to reduce cycle time to meet takt time. In the Plan phase, voice-of-the-customer interviews were conducted. In the Do phase, the baseline workflow was mapped and billing data were analyzed. In the Study phase, cycle time, takt time, and capacity analysis metrics were calculated at baseline. In the Act phase, interventions were implemented to increase efficiency by reducing NVA activities and increasing value-added activities, and metrics were reassessed after intervention. An 8% increase in appointment requests was noted from baseline to after intervention, and the cycle time for appointment scheduling decreased by 11%, demonstrating increased efficiency. Process steps decreased from 15 to 10, eliminating NVA activities and rework and waiting, two types of waste. Although efficiency increased, the number of total appointments scheduled weekly increased by 4%, resulting in a reduced takt time, or a shorter time to schedule each appointment to meet demand. A capacity analysis demonstrated that even after interventions, an additional 0.5 full-time employee is required to reduce cycle time to equal takt time. Capacity analysis creates a scalable framework for the scheduling team and facilitates movement from reactive to proactive staffing, which can be applied throughout the research enterprise.

Cycle time reduction in manufacturing industry by designing a dedicated fixture: A case study

The principal commercial requirement of any manufacturing system is directed towards a growth in productivity. One of the options for achieving higher productivity is reducing the cycle time. Cycle time comprises of the following time element: operation, loading/unloading, set-up and idleness. In this work a case study of a reputed construction equipment manufacturing company of India is considered where in it was observed that the demand for the 4Ton compactors remained unmet as there were no dedicated fixtures for the tack welding operation of those compactors. This welding work was being performed using hook and carrier by trial and error method. This led to inefficient utilization of man, machine, money and increase in manufacturing time. So there was a need to design the dedicated fixture so as to reduce the cycle time of tack welding operation. Benefits of this new fixture are twofold. It reduces setup time because it eliminates marking for each job, positioning by trial and error method and hence increases the productivity of 4Ton compactor. Also, usage of fixture calls for semiskilled labor instead of skilled labor, reducing labor cost for improved production rate.Keywords: Productivity, compactor, fixture, setup time, cycle time

Editorial 2017 Best Paper Award

Each year the Transactions on Semiconductor Manufacturing recognizes the best paper published during the previous calendar year. This year 9 papers were nominated by our reviewers and members of our Editorial Board and Steering Committee, out of a total of 78 papers published in our pages in 2017. From among these, the members of the Editorial Board and Steering Committee selected the paper entitled “A Novel Dynamic Process Control Scheme to Improve Cycle Time in Fabs” by Dr. Michael Hassoun of the Department of Industrial Engineering and Management of Ariel University in Israel. This paper continues an ongoing line of research examining the impact of process control policies on the tradeoff between cycle time and yield in wafer fabrication. The primary finding is that modest relaxation of process control parameters to reduce time spent adjusting production equipment when it is in high demand can often reduce cycle time with minimal negative impact. A number of fruitful extensions for future work are also discussed, holding out the possibility of improved integration of scheduling and process control techniques. On behalf of the TSM community, I have the pleasure of congratulating Dr. Hassoun on this recognition, and of wishing him continued success in future.

Influence of contents rate and dispersion of carbon nanotubes on interfacial adhesion between continuous fiber reinforced thermoplastics and injection resin

Fiber reinforced plastics have been expected as an alternative of metal materials in order to reduce the lightweight of the automotive and the environmental loading. Carbon fiber reinforced thermoplastics (CFRTP) have been studied from the view point of reducing cycle time and recycling of polymer materials. Prepreg compression molding (PCM) enables to provide the excellent mechanical property. However, PCM is difficult to form complex shape. On the other hand, hybrid injection molding (HIM) has attracted attention because HIM makes it possible to form complex shape. However, the mechanical property of molded parts are affected by the interlaminar shear strength between continuous fiber reinforced thermoplastics and injection molded parts. Some researchers reported interlaminar shear strength improve by use of carbon nanotubes (CNTs). Therefore, we aimed at improving interfacial adhesion by preparing a film with CNT added in matrix and inserting the film at the interface of hybrid injection molded parts. We conducted short beam test on specimens inserted films. When CNT/PP film was used, the interfacial shear strength was improved compared to when no film was used. When the CNT was in the low dispersion state, the interfacial shear strength rose gently up to 1.0 wt% and dropped greatly at 3.0wt%. On the other hand, when the CNT was in the highly dispersed state, the interfacial shear strength rose up to 0.5 wt%, and thereafter dropped. When the CNT content was 1.0 wt%, the CF entered deep into interface at low dispersion. However, the interface was smooth and entry of CF could not be confirmed on the peeled surface at high dispersion. There is an optimum value for the content and dispersibility of CNT in the film.

Flow and heat transfer during compression resin transfer moulding of highly reactive epoxies

Fast-cure epoxy systems are used for the mass production of composite parts with cycle times in the minute range. One of the major difficulties observed when processing fast-cure resins is their strong exothermic reaction during cure. This may result in a significant temperature overshoot and large temperature gradients over the thickness, and therefore gradients, in glass transition temperature, shrinkage and residual stress. Hence, the cure reaction during the injection, impregnation, compaction and curing stages need to be understood and optimised in order to reduce cycle time without sacrificing mould filling and part quality. A possibility to process such highly reactive epoxies is the compression resin transfer moulding process (CRTM), where the preform is impregnated in through-thickness direction, leading to reduced cycle times. The aim of this work is to identify processing constraints that the different CRTM variations present when using fast-curing resins. We have developed a multi-physics model to compare three variations of the CRTM process: gap injection, direct dosing and wet pressing, by studying their fluid flow and the exothermic reaction. The models show the importance of the injection strategy to avoid temperature overshoot, which can occur before the part is fully impregnated. Our results show that when impregnation time is a limiting factor, wet pressing appears to be a favourable approach for fast composite processing, doubling the available impregnation time before gel.

Productivity Enhancement: Implementing and Analyzing Clustering Method in Manufacturing of Gearbox Housing

Productivity is the index of performance with which assets, each human and material, are converted into beneficial services and items. The vital relevance of the present work was to research the elements involved in the development of productiveness in all its types which include capital, material, labor, machine, and general productivity at the enterprise. This turned into received by means of reducing the manufacturing cost of the component through reduction of its cycle time and increasing the month-to-month production implementing clustering method. The experimentation found out that the usage of proposed methods and improved tooling has increased the monthly production rate by 20% by dint of reduced cycle time. Rejection rate, i.e., defected components has decreased up to 2%. A reduction of 9.7% in part manufacturing cost was recorded. Tooling cost has decreased by way of greater than 10%. Up to 50% saving in inspection cost was reported on account of closer dimensional tolerances and superior finish achieved on manufactured parts. An improvement of 5.25% was claimed in total productivity.

Process Improvement and Reduction of Cycle Time for GTMC CNC Used in Machining of Multistage Pump

This paper present the improvement in a machining process by using the 5S tools and Taguchi technique. The quality and productivity play significant role in today‟s pump manufacturing industry, from the customer‟s point of view, therefore every production unit should concern about quality of the product. The reduction in cycle time of a components in an industry by implementing lean tool (2S) and experimental study to optimize cutting parameters during machining of FG260 (grey cast-iron) to minimization of surface roughness (Ra) and cycle time of FG260 affect the aesthetical aspect of the final product and hence it is essential to select the best combination values of the CNC turning process parameters to optimize. An orthogonal array, Signal to noise(S/N) ratio and analysis of variance (ANOVA) were employed to analyze the effects and contributions of cutting speed, feed rate and depth of cut on the response variable. The experiments were carried out on a CNC turning, using coated carbide insert for the machining of Grey cast-iron. The experiments were carried out as per L9 orthogonal array.

Reduction of Arc-Furnace Smelting Cycle Time at Tagmet

We discuss a technology for reducing the smelting cycle time and detecting unscheduled interruptions during unpowered operations associated with steel smelting in arc furnaces. We have implemented several measures to reduce the duration of smelting at TAGMET by 10%.

Machining Powerhouses

A theme in the energy sector is the need to cut challenging materials, often in a single cycle. Three companies have invested in machinery that delivers on power, plus cycle and set-up time reduction, while another has boosted performance via CADCAM software adoption

Fully automated sample preparation procedure to measure drugs of abuse in plasma by liquid chromatography tandem mass spectrometry.

For the analysis of drugs and pharmaceutical compounds in biological matrices, extraction procedures are typically used for LC-MS/MS analysis often requiring manual steps in sample preparation. In this study, we report a fully automated extraction method carried out by a programable liquid handler directly coupled to an LC-MS/MS system for the determination of 42 components (illicit drugs and/or metabolites) (plus 20 deuterated internal standards). The acquisition was performed in positive ionization mode with up to 15 MRM transitions per compound, each with optimized collision energy (MRM spectrum mode) to enable qualitative library searching in addition to quantitation. After placing the sample tube into the system, no further intervention was necessary: automated preparation used 50μL of blood or plasma with 3μL of extracted sample injected for analysis. The method was validated according to the requirements of ISO 15189. The limit of detection and quantification was 1-5ng/mL depending on the compound. Stability experiments found that historic calibration curve data files could accurately quantify for up to 1month with less than 20% uncertainty. Comparison to a QuEChERS method was made using patient samples providing a regression correlation R2 = 0.98 between the two methods. This approach was successfully designed to support parallel sample preparation and analysis therefore significantly increasing sample throughput and reduced cycle times. Graphical abstract ᅟ.

Implementation of MCDM model in lean manufacturing using grey relational analysis in automotive industry

The present economic situation shows the consistent demand for profitable solutions that allow business organizations to gain better ad-vantage. Due to this reason, many organizations search for methodologies that allow them to improve their products and services improve their processes, reduce costs, and improve the profit and customer satisfaction. This has been implemented through lean techniques in their managerial and production methods. As we know Lean production system mainly emphasizes on the waste elimination, using simple and visual techniques. This paper is an attempt to optimize process layout and waste expulsion for automotive powertrain in a leading automo-tive company by using lean manufacturing techniques. In this paper, the existing process in place for machining of cam shaft is analysed and process layout is optimized to reduce cycle time and lead time. In order to reduce the cycle time, the process parameters such a speed, feed and depth of cut are optimized for increased material removal rate (MRR) and decreased surface roughness (RA) by using Grey Relational Analysis (GRA) technique. As MRR is inversely related to cycle time, optimization of parameters for higher MRR reduces the cycle time. Grey Relational Analysis is done by using Design Xpert software.

Toward cycle time reduction in manufacturing SMEs: Proposal and evaluation

ABSTRACTThis article presented an exploratory study to conceptualize and validate a Lean Six Sigma (LSS) deployment roadmap for manufacturing small and medium-sized enterprises (SMEs). The existing LSS theories were developed for large businesses and ignore the restrictive resource capabilities of SMEs. The LSS framework developed based on the conceptual insights consisted of three parts: constructs, methodology, and tools. The application of proposed framework was illustrated through the case study of a small-scale engineering enterprise facing chronic delays in the delivery of one of the engineering assemblies leading to client dissatisfaction. The case findings showed an annual cost saving of USD 54,600 in form of eliminated liquidated damages.

Investigating the effects of reduced technological constraints on cycle time through simulation modelling for automated steel wall framing

Off-site construction constitutes a paradigm shift in construction promoting improved sustainability. At present, North Americaäó»s building construction sector is still dominated by conventional stick-built construction, which is prone to excessive material waste, longer cycle times, high labour costs, and lower quality. In contrast, inspired by the manufacturing industry, off-site construction is an approach in which building components are prefabricated in factories and transported to the construction site for on-site assembly. As the concept of off-site prefabrication gains momentum within the domain of construction, some home builders are bringing the traditional industry practice into a factory setting, thus resulting in stick-building- under-a-roof. This paper describes the development of simulation models for the automated light gauge steel framing process using discrete-event simulation mimicking real-time machine production capacity and cycle time. At present, the literature on the development of such models for automated construction machinery is lacking; in this context, this paper aims to showcase the advantages of simulation as a decision-making support tool. Construction of such models provides a useful tool for understanding bottlenecks in machine operations that can be addressed to meet local demands. Since the steel framing process primarily consists of manual assembly and fastening of cold-formed steel (CFS) frames, these models showcase the potential to increase the level of automation through the addition of various mechanical and control modifications to an existing prototype steel framing machine. The results show that cycle time reductions of 13 percent or greater are possible by applying the proposed modifications.

Impact of stitching on permeability and mechanical properties of preforms manufactured by dry fiber placement

Dry fiber placement (DFP) is a technology that enables outstandingly high mechanical performance of composite parts, as preform structures with load‐related fiber orientations can be created with minimum of fiber crimp and undulation. Yet, the poor impregnation behavior of DFP preforms during liquid composite molding processing methods remains a main challenge. Encouraging an out‐of‐plane impregnation, for example, by using a vacuum assisted or compression resin transfer molding process, reduces the flow length within the preform and is a first step towards reducing cycle times. However, further improvements are required in order to apply DFP preforming methods in serial production. In a previous work, the influence of various process parameters as well as post‐treatment steps on out‐of‐plane permeability have been investigated with the conclusion, that tufting/stitching led to the highest increase in out‐of‐plane permeability (more than two decades). For further understanding, this study deals with the influence of a stitching step on the out‐of‐plane permeability of DFP preforms as well as the mechanical properties of the finished laminate depending on a variety of stitching parameters such as thread tension during stitching, denier of the used thread, stitch distance, seam distance, seam displacement, and treated DFP layup. It is shown that the biggest impact on out‐of‐plane permeability results from the achieved stitching density (as a product of stitch distance and seam distance) and denier while thread tension and seam displacement show negligible effects. For the mechanical properties, it can be stated that the presence of stitching channels in thickness directions leads to a minor decrease of tensile properties while bending properties are more significantly reduced by about 30%. POLYM. COMPOS., 40:1631–1642, 2019. © 2018 Society of Plastics Engineers

Operator Idle Time Rectification as the Solution to Cycle Time Reduction in Oxygen Sensor Production

In factory works, there are systems that need to be followed in order to create a well-ordered process such that Just In Time (JIT) production can be reached. The lean manufacturing principle is one of the solutions for sustainable factory system. Within the lean manufacturing system, there are many tools that can be applied for sustainability and improvement. In this paper, Kaizen, the Japanese business philosophy as one of the lean manufacturing principle tools, is applied to give an improvement in reducing production cost. It is done by continuous observation, note, and analysis of time consumption required by the production line. A new Kaizen analysis from a new point of view is applied by comparing the impact of adding operator to the production line to the Over Time (OT) cost and renewing part of the machine-tool mapping for faster Takt Time (TT). Kaizen activity was successfully analyzed. It shows that the production Cycle Time (CT) can be deducted by 0.5 seconds which will reduce the production revenue cost by 10.8%.

Optimization of Laser Marking Machine by Design of Fixture to Reduce Cycle Time

Optimization of Laser Marking Machine by Design of Fixture to Reduce Cycle Time

Numerical and experimental investigation of process parameters optimization in plastic injection molding using multi-criteria decision making

In plastic injection molding (PIM), the process parameters such as packing pressure, melt temperature, and cooling time should be adjusted and optimized for high product quality and high productivity. Warpage is one of the major defects in the PIM and should be minimized for high quality. Cycle time should be minimized for the high productivity. In addition to the warpage and the cycle time, clamping force affects the product both the quality and the productivity. Therefore, for the high product quality and the high productivity, it is important to minimize the warpage, the cycle time and the clamping force simultaneously. In this paper, a multi-objective optimization of process parameters in PIM for minimizing three objectives is performed. Numerical simulation in the PIM is generally so intensive that a sequential approximate optimization using radial basis function network is adopted to determine the optimal process parameters. The radar chart is used to perform the trade-off analysis among three objective functions. In addition, the better and worse solution are newly introduced for the trade-off analysis. It is found through the trade-off analysis that all objective functions of the conformal cooling channel are well improved in comparison with the ones of the conventional cooling channel. Therefore, 43% warpage reduction, 1,7% clamping force reduction, and 47% cycle time reduction can successfully be achieved using the conformal cooling channel. Based on the numerical result, the experiment using PIM machine (GL30-LP, Sodick) is carried out. The conformal cooling channel is developed by the metal 3D printer (OPM250L, Sodick). Through the numerical and experimental result, the validity of the proposed approach is examined.

An ergonomics prototype of adjustable chin stands aid for visual mechanical inspection at electronic manufacturing-based company in Kuantan, Malaysia

Chin stands aid is a device designed to reduce fatigue on the chin during the Visual Mechanical Inspection (VMI) task for operators in TT Electronic Sdn Bhd, Kuantan, Malaysia. It is also used to reduce cycle time and also improve employee well-being in terms of comfort. In this project, a 3D model of chin stands aid with an ergonomics approach is created using SOLIDWORKS software. Two different concepts were designed and the best one is chosen based on the Pugh concept selection method, concept screening and also concept scoring. After the selection of concepts is done, a prototype of chin stands aid will be developed and a simulation of the prototype is performed. The simulation has been executed by using Workbench ANSYS software as a tool. Stress analysis, deformation analysis, and fatigue analysis have been done to know the strength and lifespan of the product. The prototype also has been tested to know the functionality and also comfortability for the user to use the chin stands aid.

Potential of on-board energy recovery systems to reduce the costs of diesel–electric mine truck haulage

ABSTRACTOn-board energy recovery systems (ERSs) are expected to reduce fuel consumption of open-pit mine haul trucks. However, the additional mass of an ERS would reduce the truck’s payload, hence reducing productivity, effectively increasing other haul-related costs. Using a simulation program incorporating appropriate models for a diesel-electric mine haul truck, capital costs, operating costs and four energy recovery technologies, this paper investigates how various ERS technologies would affect overall haulage cost. Two energy re-use strategies are considered. The power augmentation strategy, which aims to reduce cycle times, promises greater savings than the fuel replacement strategy, which reduces engine power using recovered power. The ERS technologies found to be best suited to the application are fast charging LiFePO4 batteries, and electro-mechanical flywheels. Using the power augmentation strategy, the potential cost reduction for both technologies under ideal conditions is 7%. Restrictions on exploiting the full potential of ERS systems are highlighted and discussed.