Application of Kaizen Lean approach to reduce rejections and failure cost at Shop floor of a wire harness manufacturing company

116-123Kaizen is a basic tool of lean manufacturing which is useful for better improvement and cost effectiveness in different organizations. This study describes a sequential method that uses kaizen continuous improvement approach to eliminate the lock release problem of band harness in a Wire Harness Manufacturing unit. Due to releasing of this self-locking type tie band, wire harness was not holding properly against the bracket and wires were not properly tightened which results in high rejection level of the product. Further, it also affects overall quality rating and increasing the rework cost significantly. In present study four problems which are responsible for rejections, are identified through brainstorming. Pareto analysis and rating method are used to know the major problem, responsible for highest rejections and why-why analysis is used to find out the root cause of the identified problem. To eliminate this cause, step by step procedure based on lean manufacturing approach, is applied in the case company. Statistical quality control tools are also used to analyze the problem. This study results in total cost saving of 535.20 $ per annum and beyond this some other tangible or intangible benefits were also observed

Critical success factors of lean manufacturing for Indian ceramic industries: Modelling through interpretive ranking process

271-281In India, majority of manufacturing organizations comes under small and medium size enterprises (SMEs) that are recognized as backbone for the economy by contributing a significant amount in gross domestic product (GDP). In the competitive business environment, SMEs are trying to enhance the value of their production and services on decimating the non-productive activities from their manufacturing systems. It has been reported in previous explorations that lean manufacturing (LM) is an approach to recognize and eliminate different forms of waste from the production process, and improve the business performance. Therefore, SMEs has to follow lean manufacturing to ensure sustainable profitability. To optimise the LM implementation benefits, organization/s must see the different success factors thoroughly. So far, critical success factors (CSFs) of lean manufacturing in labour intensive SMEs were not explored systematically. In this study, CSFs for implementing lean are extracted from literature and were analysedand validated after discussion held with relevant industrial experts/academicians. Interpretive ranking process (IRP) technique was employed to observe the relationship amongst the CSFs. To check the interpretations and pair-wise comparison, a dominance system graph for each performance measures was developed. The results revealed that regular training and education for workers, proper selection of lean tools/techniques and low scrap/rework/elimination of waste are the most CSFs for implementing lean in Indian ceramic SME sector

Improving the Optical and Thermoelectric Properties of Cs2InAgCl6 with Substitutional Doping: A DFT Insight

New generation Indium based lead-free Cs2InAgCl6 is a promising halide material in photovoltaic applications due to its good air stability and non-toxic behavior. But its wide band gap (>3 eV) is not suitable for solar spectrum and hence reducing the photoelectronic efficiency for device applications. Here we report a significant band gap reduction from 3.3 eV to 0.6 eV by substitutional doping and its effect on opto-electronic and opto-thermoelectric properties from first-principles study. The results predict that Sn/Pb and Ga & Cu co-doping enhance the density of states significantly near the valence band maximum (VBM) and thus reduce the band gap by shifting the VBM upward while the alkali-metals (K/Rb) slightly increase the band gap. A strong absorption peak near Shockley-Queisser limit is observed in co-doped case while in Sn/Pb-doped case, we notice a peak in the middle of the visible region of solar spectrum. The nature of band gap is indirect with Cu-Ga/Pb/Sn doping with a significant reduction in the band gap. We observe a significant increase in the power factor (PF) (2.03 mW/mK2) for n-type carrier in Pb-dpoing, which is ~3.5 times higher than the pristine case (0.6 mW/mK2) at 500 K

Modeling and analysis of surface roughness in fused deposition modeling based on infill patterns

92-99This paper presents an approach of modeling for surface roughness of Polylactic Acid (PLA) polymer components printed with Fused Deposition Modeling (FDM) based Additive Manufacturing (AM) process. With additive manufacturing technology one can build the components of metal, polymers and variety of composites with good dimensional accuracy. FDM is one of the additive manufacturing process which is used to build products of various polymers. In this investigation PLA components are built using FDM with different Infill Patterns viz. Zigzag, Triangles and Gyroid. Based on surface roughness measurement of components, predictive mathematical models for surface roughness are generated for different infill patterns. The analysis of surface roughness based on layer thickness and infill pattern is presented. The error between predictive surface roughness and experimental surface roughness ranges between 0.1 to 9.5%. For this investigation Gyroid infill pattern shows favourable results for surface roughness. The workable ranges for process parameter under investigation are infill percentage of 70 to 90 %, layer thickness of 0.2 to 0.22 mm and printing speed of 70 to 90 mm/s

Reusing equipment in cells reconfiguration for a lean and sustainable production

Production cells are considered a flexible production system capable to face new market demands. In most cases, this is provided by their capability of reconfiguration, i.e., by removing/adding new equipment needed and/or reusing the existent equipment for the new demand. Nevertheless, some companies are not conveniently exploring this opportunity. What happened, many times, is the design of a complete new cell replacing all the equipment and sending the existent machinery to the warehouse. This is a decision that, economically and environmentally, is costly. Furthermore, knowing that some equipment could be reused for a new product. In a Lean Thinking, this is waste and a Lean company should promote a more efficient and sustainable production. This paper introduces a study in a Lean company that has developed practices to reuse equipment. The reasons for the non-reuse of the existent equipment were studied and some strategies were proposed to turn this equipment available and visible for reuse. Also, the benefits of reusing equipment related with saved costs and contribution to the environmental sustainability, are discussed.The authors acknowledge the company for allowing this study. This work has been supported by FCT – FundaXYo para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019

Spatial–temporal spectroscopy characterizations and electronic structure of methylammonium perovskites

Using time-resolved laser-scanning confocal microscopy and ultrafast optical pump/THz probe spectroscopy, we measure photoluminescence and THz-conductivity in perovskite micro-crystals and films. Photoluminescence quenching and lifetime variations occur from local heterogeneity. Ultrafast THz-spectra measure sharp quantum transitions from excitonic Rydberg states, providing weakly bound excitons with a binding energy of ~13.5 meV at low temperatures. Ab-initio electronic structure calculations give a direct band gap of 1.64 eV, a dielectric constant ~18, heavy electrons, and light holes, resulting in weakly bound excitons, consistent with the binding energies from experiment. The complementary spectroscopy and simulations reveal fundamental insights into perovskite light-matter interactions

Resistance to amorphisation in Ca1-xLa2x/3TiO3 perovskites – a bulk ion-irradiation study

The changes induced from 1 MeV Kr+ and 5 MeV Au+ ion irradiation at room temperature have been utilised to determine the impact of cation vacancies on the radiation damage response of bulk Ca1-xLa2x/3TiO3 perovskite structured ceramics. Perovskite systems have long been considered as candidate waste forms for the disposition of actinide wastes, and doping with multi-valent elements such as Pu may lead to cation deficiency. Based on GAXRD and TEM analysis, two regions of resistance/susceptibility to amorphisation have been confirmed with reference to CaTiO3. Increased resistance to amorphisation has been observed for 0.1 ≤ x ≤ 0.4, with an increased susceptibility to amorphisation for x ≥ 0.5. It is proposed that these processes are induced by enhanced recovery from radiation damage for 0.1 ≤ x ≤ 0.4, and reduced tolerance for disorder/the increasingly covalent nature of the A-O bond for x ≥ 0.5. Lattice parameter analysis of the x = 0 and 0.5 samples showed a saturation in radiation damage induced volume swelling at 4.7 ± 0.1% and 1.8 ± 0.1%, respectively, while the saturation limit for the b parameter was lower than the respective a and c orthorhombic parameters. In the x = 0.2 and 0.4 samples, amorphisation was not observed, however the b parameter was found to swell to a lesser extent than the a and c parameters. Swelling was not observed for the ion irradiated x ≥ 0.6 samples