Construction Projects.
We can apply Lean Six Sigma in service-based environments, such as turnaround projects. It also provides evidence of the tangible benefits.
that can be achieved within specialty construction operations using process improvement strategies.
Welding is commonly used to connect sections of pipeline during initial construction projects. Because welded connections serve as a critical point of failure in pressurized pipeline systems, much time is spent on the process of welding sections of pipeline together.
Some types of welding defects that are typically observed include lack of fusion and porosity.
JV Industrial Companies (JVIC), Ltd., is an industry-leading turnaround, construction, and fabrication services organization headquartered near
Houston, Texas.
The project team conducted problem-solving sessions to develop potential solutions for the two root causes of defective welds identified previously through the FMEA problem-solving tool and the Pareto diagram after collecting enough data from defect reports. They identified focused solutions for reducing defective welds. Reduce the wind impact on the welding process, inspecting windshields and training welders on how to use windshields.
We can use six Sigma methods in construction projects to reduce workflow variability and provide more concrete measures of project performance.
By implementing windshield standards, training welders through a specialized training center, and instituting eyesight tests for welders company-wide, the weld repair rate decreased by over 25%, which translated into a savings of $90,000 for this company.
Source:
Anderson, N.C. and Kovach, J.V. (2014) “Reducing welding defects in turnaround projects: A lean six sigma case study,” Quality Engineering, 26(2), pp. 168–181. Available at: https://doi.org/10.1080/08982112.2013.801492.
Rubber Gloves factory in Thailand.
The analysis by employing Six Sigma and DMAIC showed that the oven’s temperature and conveyor’s speed influenced the amount of defective gloves produced. After optimizing these two process variables, a reduction of about 50 percent in the “leaking” gloves defect was achieved, which helped the company to reduce its defects and maintain its major customer.
Two major defects were leaking and dirty gloves. The miscellaneous category comprised other types of defects, such as misshaped, sticky gloves, etc. they collected Defects data for twenty days. The Pareto chart showed that the highest rate of defects was caused by leaking gloves. In particular, this type of defect contributed to over 60% of the overall amount of defects.
Once that the inputs, outputs and sequence of the process were understood with the help of the flowchart, they carried an analysis out to identify the root cause(s) of the leaking gloves quality defect. Several brainstorming sessions were conducted to identify, based on the improvement team members’ experience, potential causes why the leaking problem in gloves occurred. All members of the team took part in the brainstorming sessions, where they could think and take part freely.
In particular, an experiment was designed to investigate whether the combination of the factors oven’s temperature and conveyor’s speed had a negative
effect on the process, causing leaking gloves.
After they statistically proved that the temperature and speed had a correlation with the number of leaking gloves, the next step was to determine the optimum temperature and speed that would result in the lowest amount of defects.
A reduction in the amount of defects was obtained by determining the optimum oven’s temperature and conveyor’s speed, which were defined as 230 C and 650 RPM, respectively. For the leak defect type, the improvement was 57% .
As long as the organization continues embracing Lean Six Sigma within its continuous improvement culture, and applies its concepts and principles to systematically solve quality problems, we believe that benefits such as cost savings, increase in products’ quality and customer satisfactions will be achieved.
Source:
Jirasukprasert, P. et al. (2014) “A six sigma and DMAIC application for the reduction of defects in a rubber gloves manufacturing process,” International Journal of Lean Six Sigma, 5(1), pp. 2–21. Available at: https://doi.org/10.1108/ijlss-03-2013-0020.