Exploring a Six Sigma Success Story

This project commenced when an executive steering committee, consisting of high-ranking leaders, responded to a surge in customer complaints. Trained in Six Sigma, the committee used Pareto analysis to scrutinize customer issues over the past year, determining solder problems as the most significant issue.

A program manager, assigned to a specific missile project, was selected as the project sponsor, and a top-tier Six Sigma team was assembled to pinpoint project opportunities.

Under the technical guidance of a Master Black Belt, the team engaged in the Define, Measure, Analyze, Improve, Control (DMAIC) cycle. After specifying Critical to Quality (CTQ) measures, the team carried out a Pareto analysis on solder defects types, leading to the establishment of a wave solder team and a subproject.

This team, comprising a process engineer, wave solder machine operator, solder inspector, and touch-up solder operator, set up a status reporting system for progress tracking, including regular updates for the project manager, a key factor for success.

A Black Belt selected to support the wave solder team began by offering training on core process improvement principles and methods. Various tasks were identified and assigned, including data collection, developing ‘as is’ and ‘should be’ process maps, and executing process audits.

Through these activities, the team discovered:

1. Touch-up occurred before data collection as solder problems were so common that touch-up was viewed as part of the soldering process.
2. The majority of defects were touch-up defects, not wave solder defects.
3. The equipment was in dire need of maintenance, with no preventive maintenance program in place.

In response, the team proposed several immediate alterations:

1. Inspection should be carried out right after wave solder and before touch-up.
2. A control chart should be used for results analysis.
3. Comprehensive maintenance of the process should be conducted.

When the implementation of these recommendations met resistance, the executive steering committee intervened and instructed the sponsor to provide immediate assistance. The sponsor rallied the support of the quality and maintenance managers, and established a mid-level management team for more frequent project status reviews. The sponsor also started daily walkthroughs of the area to interact with team members.

A month after these changes, defects fell by 50%, and productivity rose significantly.

Following this, the Black Belt and process engineer initiated a series of experiments. These Design of Experiments (DOEs) debunked several long-standing assumptions, leading to quality improvements and cost savings by adjusting procedures based on new insights. Ad hoc experiments, though less sophisticated, still led to significant improvements at minimal cost.

As a result of these various changes, over ten months, the defect rate dropped by 1,000%, and productivity increased by 500% in terms of labor hours per board. This progress was made despite only a few of the proposed improvements being fully implemented.

In addition to these quality improvements and cost reductions, considerable factory space was freed up for more productive use, leading senior leadership to reconsider their facility expansion plans.