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research-article2018
WMR0010.1177/0734242X18796205Waste Management & ResearchGoyal et al.
Short Communication
Waste reduction through Kaizen approach: A case study of a company in India
Waste Management & Research 2019, Vol. 37(1) 102–107 © The Author(s) 2018 Article reuse guidelines: sagepub.com/journals-permissions https://doi.org/10.1177/0734242X18796205 DOI: 10.1177/0734242X18796205 journals.sagepub.com/home/wmr
Ankur Goyal1,2, Rajat Agrawal3, Rakesh Kumar Chokhani4 and Chiraranjan Saha4
Abstract The growth in manufacturing activities for economic development is putting a lot of pressure on the environment. One such impact is due to generation of waste from hazardous material. The best way for hazardous waste management is either elimination or substitution with non-hazardous material. The case study in the present paper is focused on the problem of hazardous waste reduction in absence of non-hazardous substitution. In absence of any non-hazardous substitute of hazardous material, waste generation can be reduced using improvement techniques such as Kaizen to improve the manufacturing process. An Indian company improved the manufacturing procedure with very low cost to reduce waste generation of hazardous material. The outcome of this Kaizen project is the reduction of waste by 13.8% at very low cost. Along with waste reduction, cost saving, and other resource savings are another benefits. This case study provides insight about the use of Kaizen for environmentally sustainable manufacturing. Keywords Waste reduction, Kaizen, continuous improvement, ecological footprint, sustainable manufacturing Received 13th February 2018, accepted 27th July 2018 by Associate Editor David Ross.
Introduction Developing countries are eager to adopt emerging technologies for higher productivity, increased efficiency, and decreased pollution in the race for development. Along with these, technologies may bring risks of new toxic chemicals and hazardous wastes. Environmentally friendly creation of products is required because manufacturing activities impose negative impact on the environment through waste generation, acquiring land, water, air, wood, minerals and metals. The research has emphasized that implementation techniques for sustainability should be specific to the behavior and characteristics of the process. Through continuous improvements, sustainability can be infused in any manufacturing process. The Kaizen approach is widely adopted in team-based work across the world (Aoki, 2008). The term “Kaizen” was coined by Masaaki Imai as “KAI” means changes and “ZEN” means improvement (Imai, 1986). There are numerous techniques for Kaizen where the focus is to eliminate non-value adding activities and these are well adopted across the world (Suárez-Barraza et al., 2011). Use of Kaizen in the Indian manufacturing sector is well adopted for high productivity, fewer defects, and reduced cycle time (Arya and Jain, 2014; Prashar, 2014). Researchers could not find a use of Kaizen for environmentally friendly manufacturing activities such as waste reduction. This paper describes a case study, in which hazardous waste is reduced by 13.8% with simple continual improvements in the manufacturing process at very low investment. This case study
concludes that limitation of technology can be a barrier for waste management but this barrier can be overcome using Kaizen up to some limit. The improvement program described in this paper is Kaizen because it has all the key elements (Brunet and New, 2003) via continual improvement producing incremental waste reduction in each stage (total 13.8% waste reduction) through the intellectual involvement of the production manager and experts from an insulation engineering department.
Methodology The methodology adopted for this paper is case study research based (Yin, 2003). The study was conducted in a leading manufacturer of equipment for power plants in India. It has a 74% market share in India, and it has 5th rank amongst Indian applicants for patents in the year 2017–2018. Its big size and 1Department
of Management Studies, Indian Institute of Technology Roorkee, India 2Bharat Heavy Electricals Limited, Haridwar, India 3Department of Management Studies, Indian Institute of Technology Roorkee, India 4Bharat Heavy Electricals Limited, Haridwar, India Corresponding author: Ankur Goyal, Department of Management Studies, Indian Institute of Technology, C/O Dr. Rajat Agrawal, Roorkee, Uttarakhand 247667, India. Email:
[email protected]
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Figure 1. Increase in viscosity and viscosity-rise of resin–hardener mix with vacuum pressure impregnation cycles.
innovativeness, ensures that the company has exploited technologies in waste reduction and the outcome of the improvement program can be fully credited to the Kaizen approach. During the study, data were collected by direct observations. In absence of elimination technology and non-hazardous substitution, the waste reduction program was developed under a plan– do–check–act (PDCA) cycle. The PDCA cycle is well adopted by researchers such as Prashar (2017), and Silva et al. (2017) in environmentally friendly operations.
Background of case The company manufactures large size high voltage rotating electrical machines, consisting of stator bars. For manufacturing of stator bars, Bisphenol-A type epoxy resin and methyl hexahydrophthalic anhydride hardener are used as an impregnant in the vacuum pressure impregnation (VPI) process. These two liquids are mixed in a certain ratio and commercially known as impregnating resin–hardener mix. This mixture has no substitute with non-hazardous material due to unavailability of required technology.
Problem: generation of waste The viscosity of the fresh resin–hardener mix lies in the range of 18–30 cP depending upon the temperature of measurement. Figure 1 shows the increase in value of viscosity and viscosityrise along with VPI cycles. The manufacturing process involves the use of a large quantity of the impregnating resin–hardener mix in the range of around 15000 kg for a number of impregnation cycles. Stored resin–hardener mix becomes more viscous mainly due to contamination with uncontrollable moisture (Kumar, 2011) present in pressurized nitrogen used for better impregnability, and dust, foreign particles from outside and accelerator contents from
insulation tape. These external factors cannot be eliminated in manufacturing shop conditions and a rise in viscosity occurs after each VPI cycle. High viscous impregnant has the risk of incomplete penetration and creation of voids in the insulation. To ensure void free insulation for high voltage electrical machines, above threshold norms of viscosity and viscosity-rise, the whole remaining quantity (approximately 7000 kg in this case) of the impregnating resin–hardener mix in the storage tank is discarded and replaced with the fresh impregnating resin–hardener mix. In this way, the impregnant is converted in to waste when its “viscosity” and “viscosity-rise” are reached at threshold limit.
PDCA cycle for waste reduction Plan (preparation) In order to reduce waste, a cross-functional team was formed. The team includes two experts from the production area, an expert from high voltage insulation engineering, and an expert in Kaizen. The team has cumulative experience of 87 years in industries. This cross-functional team brainstormed for identifying potential areas of improvement as shown in Figure 2. The waste reduction program was developed (Figure 3) based on the identified potential areas for improvement during brainstorming.
Do Extension of life span of resin–hardener mix. A procedure was developed for using a high viscous resin–hardener mix (Figure 4) as an impregnant. An impregnability test on a specimen (Figure 5) and monitoring of tan delta values of cured insulation (Institute of Electrical and Electronics Engineers, 2006) were deployed to control the quality of the impregnation process in addition to
104 the controlling parameters, that is, viscosity and viscosity-rise. Reduction in waste generation by lowering the numbers of VPI cycle. Increasing numbers of stator bars in each VPI cycle reduce the required numbers of VPI cycles. This further reduces reduction in residual resin–hardener mix and the exposure of stored resin–hardener mix to heat and moisture absorption. This yields reduction in waste generation per unit stator bars. In addition to waste reduction, other environmental benefits are mentioned in Table 1.
Check (monitoring) Impregnability test on specimen. Figure 5 shows the assessment of impregnability through counting of wet layers in the specimen. The specimen passes this impregnability test, if the bottom layer is found wet. Monitoring of quality of impregnated stator bars. Figure 6 shows the assessment of tan delta values with respect to viscosity of resin–hardener mix. No significant difference was found in tan delta values for stator bars impregnated with below and above threshold limits of viscosity. The difference in tan delta at 0.2 Un and 1.4 Un represents presence of voids created by a non-perfect impregnation process
Waste Management & Research 37(1) and largely governed by viscosity of the resin–hardener mix. For fresh resin–hardener mix, viscosity-rise and difference in tan delta has the coefficient of determination (r²) of 0.078. For high viscous resin–hardener mix, this coefficient of determination (r²) is 0.071. The continuation of this weak relationship represents successful utilization of highly viscous material which was earlier supposed to be discarded as waste.
Act (ensure successful implementation) The waste reduction program was carried out in 2016 in 128 VPI cycles (graph-C and graph-D in Figure 7). Due to limitation of inputs and production schedule, 33 VPI cycles have double volume of stator bars. These 128 impregnated VPI cycles are equivalent to 161 (128 + 33) VPI cycles. Also, 128 VPI cycles consist of 24 VPI cycles, carried out with an uplifted threshold limit of viscosity and viscosity-rise. The reduced environmental footprints and cost saving are shown in Table 1. This case study demonstrates the success of waste reduction based on data obtained directly from a manufacturing shop, considering all practical limitations as a matter of course.
Result As shown in Figure 7, graph-A and graph-B represent the life span of resin–hardener mix before the PDCA cycle, whereas graph-C and graph-D represent the life span of resin–hardener mix after the PDCA cycle. A higher output with the same amount of discarded resin– hardener mix produces less waste generation per unit stator bar. Also, eliminated VPI cycles reduce ecological footprints, that is, wastage in the form of residue resin–hardener mix in the impregnation tub, compressed air, water, and fumes generation.
Conclusion
Figure 2. Cause and effect diagram during brainstorming.
Recycling of waste material is considered to be a possible solution for achieving sustainability. But recycled material has certain limitations such as contamination and lower properties
Figure 3. Improvement for waste reduction developed in Indian company.
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Figure 4. Layout of procedure for extended use of resin–hardener mix.
Figure 5. Impregnated specimen and test on specimen for determining impregnability.
compared with the original raw material (Grosso et al., 2017). In sensitive systems, such downgraded materials may affect overall performance. Substitution of hazardous materials with non-hazardous materials is the most preferred solution. But in absence of substitution, reduction at source is the next optimum option for waste management. This Kaizen project demonstrated reduction of generation of waste at source through continuous improvements in the process. Authors such as Vaccari et al. (2018), and Bhanot et al. (2017) highlighted that high investment is a significant barrier in environmentally friendly operations. But the present work highlights that by using the principles of Kaizen, waste minimization can be achieved with negligible investment. In absence of required technology, radical innovation for waste reduction is not possible. Moreover, if two competitor companies acquire
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Table 1. Environmental and economic benefits from project of waste reduction of epoxy resin–hardener mix. Serial Number
Parameters
Environmental and economic benefits
1 2 3 4 5 6
Waste of resin–hardener mix Cost saving for resin–hardener mix Energy Reduction in carbon dioxide Pressurized dry nitrogen gas Water consumption
Reduced by 2, 745 kg (13.8%) Indian Rupee 1.37 million 115500 kWh (reduced by 20.5%) 98, 175 kg (reduced by 20.5%) Reduced by 20.5% Reduced by 20.5%
Figure 6. Comparison of tan delta values for average of 84 stator bars.
Figure 7. Increase in viscosity-rise with the utilization of resin–hardener mix.
Goyal et al. the same technology, Kaizen would provide a competitive edge (Soltero and Waldrip, 2002). Some companies focus on diversion of generated waste rather reduction at source (Veleva et al., 2017). This case study is useful for developing insight and interest in practitioners for focusing on waste reduction at source. The outcome of improvement confirms that the lean approach of reducing waste along with consideration of environmental impact provides synergic benefits, and the Kaizen approach in development of required solutions can provide breakthrough results. The Kaizen approach for waste reduction at source remains relevant even after the 4th industrial revolution because Industry 4.0 promises efficient waste management using advanced technologies (Agamutha, 2017), but it does not promise substitution of hazardous material with non-hazardous material. As stated by Gravitis (2007), absolute zero emission is not possible in the physical world, but “near-zero emission” is possible through reducing waste. Therefore, a 13.8% reduction in waste with uncompromised quality of product can be considered as an achievement.
Declaration of conflicting interests The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The authors received no financial support for the research, authorship, and/or publication of this article.
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