Lean Six Sigma Principal in Construction: A Literature Review Related to Conclusions

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 3, Issue 5, May 2013)

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Lean Six Sigma Principal in Construction: A Literature Review

Related to Conclusions

Sunil V. Desale

1

, Dr. S. V. Deodhar

2

1_{Department of Civil Engineering, SSVPS B S Deore College of Engineering, Dhule, India}

2

Department of Civil Engineering, SVITS Indore (M.P), India

Abstract— The critical objective of construction industries

nowadays is to complete a project within a stipulated time and cost through process standardization, minimization of waste, and organizational potential and efficient use of resources by using recent techniques such as six sigma. Most of the construction companies face poor client satisfaction due to non completion the work as per the required standard and specification. For the industry to increase its profit margin and remain competitive in the market, completion of a project as stipulated is crucial. Six sigma refers to the minimization of variation through proper work flow maintenance and it leads to performance improvement of contractors in terms of cost and quality. It ensures that construction processes become leaner and cost competitive. This paper discusses different articles and there conclusions that have been published in this

field and present a literature review.

Keywords—Lean Six Sigma and Lean, Six sigma..

I. INTRODUCTION

The Greek alphabet Sigma (σ) has become the statistical symbol and metric of process variation. The sigma scale of measurement is perfectly correlated to such characteristics as defects-per-unit, parts-per-million defectives, and the probability of a failure. Six is the number of sigma measured in a process, which has a target variation of only 3.4 per million as defects under the assumption that the process average could diverge over the long term by as much as 1.5 standard deviations. Six Sigma can be defined in several ways. Tomkins (1997) defines Six Sigma to be “a program aimed at the near-elimination of defects from every product, process and transaction.” Harry (1998) defines Six Sigma to be “a strategic initiative to boost profitability, increase market share and improve customer satisfaction through statistical tools that can lead to breakthrough quantum gains in quality.” Six Sigma was launched by Motorola in 1987.As a result of a series of changes in the quality area starting in the late 1970s, with ambitious ten-fold improvement drives. After some internal pilot implementations, Galvin, in 1987, formulated the goal of “achieving Six-Sigma capability by 1992” in a memo to all Motorola employees (Bhote, 1989).

The reduction in process variations were on-track and cost savings totaled US$13 billion with labor productivity achieved 204% increase for over period 1987–1997 (Losianowycz, 1999) to companies such as IBM, DEC, and Texas Instruments launching Six Sigma initiatives in early 1990s. However, it was only part 1995 when GE and Allied Signal launched Six Sigma that a rapid dissemination took place in non-electronic industries all over the world (Hendricks and Kelbaugh, 1998). In early 1997, the Samsung and LG Groups in Korea began to introduce Six Sigma, Samsung SDI, reported a cost savings through Six Sigma projects totaling US$150 million (Samsung SDI, 2000a). It is statistical measurement of quality level. It is a new management strategy to create quality innovation and total customer satisfaction. As a means of doing things right the first time and work smarter by using data information. (Six Sigma for Quality and Productivity Promotion ©APO 2003, ISBN: 92-833-1722-X by Sung H. Park)

II. METHODOLOGY

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III. REVIEW OF LITERATURE RELATED TO CONCLUSION

According to Muharrem Firat Yilmaz (Six Sigma within construction context as a quality initiative, performance indicator/improver, management strategy, 2012). Six Sigma can be very useful to broaden quality concept of construction industry to a more efficient form which should include financial parameters. Obviously, past researches and applications show that Six Sigma increase quality directly/indirectly considering technical and financial aspects in the construction industry even though it is not adapted properly. Process Design tools of Six Sigma have not been adapted to the construction context at least for this moment. DFSS should be adapted to the construction context properly in order to fix process design problem. Moreover, DMAIC has properly adapted and successfully implemented to the construction context as a process improvement tool. Also, DMAIC can be helpful to increase quality and quantity at the same time and it will affect technical and financial success of project considerably. Briefly, Six Sigma, as a quality initiative, aims to reduce defects and variations in processes using statistical measurements, process design and quality control analysis in order to increase (external/internal) customer satisfaction. Additionally, the integration of Six Sigma approach to the existing procedures of Project Control department makes the collaboration of Site and Office department more efficient. Six Sigma methodologies make the benefits of process improvement repeatable and coordinated which are very important for the sustainable performance improvement. Moreover, the deployment and implementation of Six Sigma does not require longer period than usual project duration unlike other improvement methods. Briefly, as a performance indicator/improver, Six Sigma provides quantitative approach and process improvement tools in order to measure performance of processes and improve it. Six Sigma was developed by professional engineers who have engineering background with the support of top executive managers. It means that philosophy of Six Sigma established in industry rather than academy and this background difference makes Six Sigma more practical and dynamic. One of the challenges of Six Sigma is to reach results quicker than other improvement methods. Even though some researchers evaluate Six Sigma as a new management approach, it can be said that adoption of Six Sigma to construction context can be realized by combination of existing quality initiatives and Six Sigma.

Due to incomplete adoption of Six Sigma tools such as DFSS and high numbers of unrepeatable tasks of construction site operations, Six Sigma should be discussed more and updated based on the characteristics of construction industry.

Hongbo Wang (2008, IEEE, PP 1 to 4) given that Six Sigma methodology has been around in industry for over a decade, it now seems unimportant to determine whether Six Sigma is better than other approaches. It is more important to learn how to enhance the Six Sigma methodology and improve implementation issues for the growing number of firms that are choosing to adopt it as a means of process improvement. The primary focus should be on improving overall management performance, not just pinpointing and counting defects. Successful implementation and growing organizational interest in six sigma method have been exploding in the last few years. However, there is still the need for more empirical research into the Six Sigma phenomenon, using rigorous research methods to validate the many uncorroborated Six Sigma claims and to test new theories or models that have been proposed to strengthen the methodology. Yet, the research territory to date has been only found within the North America region with only a few studies in Europe and Asia. Given the globalization of many companies, including those using Six Sigma, study in other parts of the world is needed to gain insights into cultural issues that may affect the theory and practice of Six Sigma.

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The work-in-simultaneity of different teams involved in the same project, which requires an efficient co-ordination, is replacing the old model that makes independent parts into mistaken project subdivision. This new design process eliminates not only waste, but also the non-adding value tasks. However, the strategy of real estate development often leads to a wrong use of this design potential and concentrates the focus only in the product. The production process is not analyzed properly until the completion of the product conception, postponing the analysis of the constructive attributes of the design solution, as well as its cost estimation. For this purpose, it must be used a more “industrial” approach and an integrated design elaboration is one of the most critical factors of the expected efficiency improvement in the building production practices.

Glenn Ballard et. Al (Presented at the 2nd Annual Conference on Lean Construction at Catolica Universidad de Chile Santiago, Chile September 1994). As currently designed, planning systems do not shield direct production from upstream variation and uncertainty. The result is longer durations and higher costs. To reduce project duration and costs, direct production must first be shielded by the introduction of a near-term, commitment level of planning, with explicit plan quality characteristics. In addition, processes must be installed to identify workable backlog, to match labor to work flow into backlog, and to measure and improve the match of DID and WILL. Stabilizing the work environment through the implementation of these planning processes results in substantial performance improvement (e.g. 30% improvement in productivity) and creates the conditions for even more substantial improvement.

Maryam Dabbaghi Tehrani (University of Boaras, Feb.2010). As stated, in order to achieve high quality level in construction industry and improve the performance, feasibility and suitability of different new philosophies in construction projects have been studied in recent years. This paper studied the idea of applying Six Sigma principle on construction industry theoretically and explored the advantages of DMAIC procedure and its potential to enhance the quality level and efficiency of the construction projects. Moreover, the flexibility of DMAIC framework in construction projects has been demonstrated and recommended how to implement each phase considering the constructional indices. This study introduced Six Sigma as a continual improvement method which offers a systematic strategy to control and coordinate all involved processes in any construction project, effectively.

Obviously, according to the text it could be concluded that the key success factors to implement Six Sigma in construction industry are nothing more than the success factors in manufacturing industry, but with more complexity and sensitivity; Appropriate definition of all critical items in any construction project, more emphasize on CTQs, proper metrics, suitable coordination scheme between all prerequisite and major processes and activities, and commitment of all involved people are able to leads the overall Six Sigma program successfully in construction industry.

Bulent Algan Tezel (A statistical approach to lean construction implementations of construction companies in Turkey, Aug. 2007). Lean production has been benefiting many manufacturers throughout the world. There are some differences between manufacturing and construction though. These differences may hinder the penetration of some of the main lean production philosophies, like just-in-time (J. I. T.) production, to the construction industry. In order to increase J. I. T., the diffusion of standardized construction elements should be promoted in the industry.

O. Salem et al (Journal of Management in Engineering © ASCE / October 2006). The benefits of the implementation were tangible: the project was under budget and three weeks ahead of schedule, and subcontractors were more satisfied with their relationships with the GC. The average PPC value was 76%, 20 points above the initial performance. No major injuries occurred during the project, and the incident rate was below that for similar projects in the same company. Most of the planners associated the performance of the project with the implementation of the lean construction techniques, and they would like to continue with most of the tools. The presented assessment tool could be used as a self assessment instrument for tracking improvements in any project. The set of techniques included could be modified or extended to fit the interests of a particular company. The tool should be led by the project manager with the support of the staff members, who are the champions of different techniques. Further research is required to validate this approach.

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We have performed in-depth comparative analyses on the existing methods for performance improvement and identified the advantages of the six sigma principle over the traditional techniques. Consequently, process simulation models have shown that construction performance improved as the sigma level advanced by enhancing the condition of CTQ. In addition, the six sigma principle provided more benefits by obtaining the optimized solution sets from performance indices, especially when the target processes are complicated and extended. In short, the six sigma principle is not only a managerial tool for productivity and quality improvement but also a systemized tool for quality and process control. With the aid of the six sigma principle method, quality variances or defects involved in construction processes can be controlled in more practical ways to fit in a desirable range. Encouraged by the benefits of six sigma principle application, future research will concentrate on developing detailed guidelines on the CTQ control of target factors based on the diverse characteristics of many different companies because the customization of the six sigma principle strategy facilitates construction firms to achieve their own process evaluation paradigm. For these objectives, advanced financial feasibility analysis should be developed before the implementation of the six sigma principle to a real construction operation.

Apollo Tutesigensi and Valeri Pleim (White Rose Research Online) the work reported in this paper was undertaken to explore the extent to which 6σ is implemented in construction SMEs and to identify the reasons that explain the state of affairs. This was pursued using an online questionnaire targeted at a random sample from a population of construction SMEs in a widely used and relatively large company database (FAME – which contains information about over 3 million companies in the United Kingdom and Ireland). It was found that none of the SMEs in the sample implemented a 6σ programme in their organization. There is a tendency to explain the construction industry’s performance relative to other industries on account of its uniqueness. While the uniqueness of the construction industry can be understood, it should be noted that there are developments taking place in the construction industry, such as increasing

competitiveness, framework agreements and

'enlightenment' that are continually diminishing the uniqueness argument.

The reasons advanced for not implementing 6σ from the sample were, in descending order of importance, as follows: lack of knowledge about 6σ programme; lack of resources (human, time, money); 6σ programme not required by customers; other sufficient quality system in use; 6σ provides no perceived benefits; and end users not prepared to pay for 6σ programme. These reasons highlight three main issues: the external environment within which construction SMEs operate, the mode of delivery of construction industry products (project work) and the nature of 6σ as a quantitative approach to managing quality.

IV. CONCLUSION

This paper recognizes that vast literature was obtainable on six sigma philosophy, which gives a wide idea of precedent practices and researches carried across the globe. Six sigma philosophy is widely accepted by manufacturing/production industries and it also possible to implemented in construction industry with little modification. More research work is still required in this field, so great scope of research is accessible for new researchers in this field. Past case study disclose that it required team efforts involving top management and every worker in the organization to fully employ the philosophy. However, consciousness among consultant, engineers and employees regarding six sigma in construction should be produced. From various literatures conclusion author feel that, uses of six sigma in construction industry under different situation plays significant role.

REFERENCES

[1] Muharrem Firat Yilmaz “Six Sigma within Construction Context as a quality initiative, Performance Indicator/Improver and Management Strategy”

[2] Qun Zhang (Corresponding Author), Muhammad Irfan, Muhammad Aamir Obaid Khattak, Xiaoning Zhu “Lean Six Sigma: A Literature Review”

[3] Thomas J. Zugelder “Lean Six Sigma Literature: A Review and Agenda for Future Research” 2012

[4] James E. Brady & Theodore T. Allen “Six Sigma Literature: A Review and Agenda For Future Research”

[5] Hongbo Wang; Advanced Vocational and Technical College “A Review of Six Sigma Approach: Methodology, Implementation and Future Research”

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[7] Vinay Mudholkar, “UK: West Coast High Speed Rail Project (WCRM): Six-Sigma for Best Quality Delivery”

[8] Dr Ingolf Stückrath “Six Sigma and The road To Success”

[9] Yewande Adeyemi “An Analysis of six sigma at small vs. large manufacturing companies”

[10] Douglas C. Montgomery1 and William H.Woodall2 “An Overview of Six Sigma”