Lean Six Sigma Research Application In Construction Industry

Construction industry presents an extremely complex combined process, production flow, various structures, high quality requirements and a long construction cycle. Large quantities of materials (concrete, steel, etc.) and time are wasted during building construction due to management procedures, the construction process and reworks. Besides, the final construction performance cannot fully meet the customers'requirements and expectations. Many researchers and project practitioners have used simple or hybrid concepts to improve the construction performance. However, very few studies have been conducted on combining Lean production concept with Six Sigma for performance improvement in the construction industry.Lean Six Sigma is a concept deriving from the integration of Lean Production and Six Sigma. It has been the majority of cases applied in the manufacturing industry and used to improve quality, reduce variation and eliminate waste in an entity. The literature did not provide a framework nor a model of its application in the construction industry.This dissertation explores practical solutions for construction performance improvement by using Lean Six Sigma method for precast composite structure (PCS) in the construction industry. A model and framework for implementing Lean Six Sigma is developed. The D-M-A-I-C model of Lean Six Sigma is applied to conduct the analysis of construction, identify essential factors to improve and thus achieve higher customer satisfaction. By proposing a workflow measurement model and through statistical analysis, the factors that lead to workflow disruption, waste and variation are eliminated. The model carries on the control improvement of the key techniques that affect a composite structure quality to complete an excellent construction project. The application of Six Sigma to improve construction process and quality and to reduce the rework of the main structure based on statistical analysis during construction is explained.The approach is then applied to steel-concrete composite structure to improve construction productivity and quality, and to control the waste of construction materials. Six composite steel-concrete beams are tested by investigating their strength and crack limit using finite element method. During the experiment, the location of the supports and cross-arrangement of dial indicator measuring specimen deflection were at 650mm from the beams end. A sample layout dial gauge is used to measure the interface slip. Based on Design for Six Sigma model (Define, Characterize, Optimize and Validate: DCOV) and by using the finite element analysis model (ANSYS), this study develops a composite steel-concrete model for scientific and economical use in the construction industry. The risk analysis software Opt Quest of Crystal ball is used to optimize steel-concrete beam design. The finite element (ANSYS) model is established to verify the technical and scientific requirements of the proposed model and to compare the results to the experimental case study results.Finally, the proposed model is evaluated for its effectiveness and efficiency. Through 13 experts, AHP method is used to score, calculate, and obtain the indicator weight. Six Sigma Scorecard is used to conduct the efficiency of the enterprise performance measurement system and to ensure project optimization in order to achieve a good method of success.This research improves the construction productivity, planning process, quality resistance to various performances and proposes the best mix proportion. These improvement measures help to overcome and reduce considerably concrete cracking and slippage in building construction. The workflow reliability, construction process, project management level and the performance of the whole project have been continuously improved. The data analysis has proven the effectiveness of the proposed method.