BUSI 616 Week 6 Application of PDCA Cycle Example

One Cycle Against Open Margins: Applying Deming's Plan-Do-Check-Act Cycle to Crown Remakes

Plan

Shenandoah Dental Arts, the composite laboratory addressing its 9.4 percent crown remake rate, found in Module/Week 5 that open margins caused 32 percent of remakes, about 3.1 percent of all crowns. Designers reported that most open margins followed scans in which the margin was blurred. The planned change has two parts: a second designer reviews the margin line on any case flagged as unclear, and designers request a rescan rather than design around a margin they cannot see. The team predicted that open-margin remakes would fall to 1.5 percent of crowns. The measure is the share of crowns returned for an open margin, coded on the check sheet already in use, so no new data system is needed. The plan also counted the cost: a second review adds perhaps five minutes per flagged case, and rescans add a day for some patients, which dentists must accept.

Do

The change was tested for four weeks with three of the twelve designers. Goetsch and Davis (2016) present the Do step as a trial run, deliberately limited, rather than a launch. That discipline is less common than it sounds: among 73 published healthcare improvement projects reviewed by Taylor et al. (2014), only 14 fully documented a series of repeated cycles, and many did not begin with small tests. A small pilot keeps the cost of failure low. The three volunteers flagged 38 of their 231 cases as unclear, asked for 11 rescans and logged the time each review took. Two dentists objected to rescan requests at first, and the intake desk explained the reason with the remake figures, which settled both complaints.

Check

Remakes appear one to three weeks after a crown ships, so results were read six weeks after the pilot began.

The pilot beat the prediction, although two remakes is a small count and the volunteers may be more careful designers than average. A fair reading is that the change probably works and is worth extending, not that the problem is solved. The review time averaged four minutes per flagged case, close to the planned five, so the cost side of the prediction also held. The laboratory will keep plotting the weekly open-margin rate, since tracking a measure over time distinguishes real change from chance variation (Benneyan et al., 2003). A pilot that beats its prediction earns a wider trial, not a victory lap.

Act

The margin review and rescan rule will be written into the design procedure for all twelve designers, and the weekly chart will confirm whether the gain holds once every designer uses it. If the rate drifts back above 2 percent for a month, the team will return to Plan and look at the scanners themselves. A second cycle will then target proximal contacts, the next bar on the Pareto chart. According to Proverbs, the diligent person's plans end in plenty, but rushing ahead ends in lack (English Standard Version Bible, 2001/2016, Proverbs 21:5); the cycle is diligence made into a routine. It asks the laboratory to slow down long enough to predict, test and learn before changing the work of sixty people, which is a form of stewardship over their time and the patients' trust.

References

Benneyan, J. C., Lloyd, R. C., & Plsek, P. E. (2003). Statistical process control as a tool for research and healthcare improvement. Quality and Safety in Health Care, 12(6), 458-464. https://doi.org/10.1136/qhc.12.6.458

English Standard Version Bible. (2016). Crossway. (Original work published 2001)

Goetsch, D. L., & Davis, S. B. (2016). Quality management for organizational excellence: Introduction to total quality (8th ed.). Pearson.

Taylor, M. J., McNicholas, C., Nicolay, C., Darzi, A., Bell, D., & Reed, J. E. (2014). Systematic review of the application of the plan-do-study-act method to improve quality in healthcare. BMJ Quality & Safety, 23(4), 290-298. https://doi.org/10.1136/bmjqs-2013-001862