In reviewing the data in the Performance Lawn Equupmeru Database, Elizabeth Burke noticed that defects received from suppliers have decreased $($worksheet Defects After Delivery$).$ Upon investigation, she learned that in $2014,$ PLE experienced some quality problems due to an increasing number of defects in materials received from suppliers. The company instituted an initiative in August $2015$ to work with suppliers to reduce these defects, to more closely coordinate deliveries, and to improve materials quality through reengineering supplier production policies. Ms$.$ Burke noted that the program appeared to reverse an