Question

You are the production manager for a widget factory. Obviously one of your business drivers is Cost, and within Cost one of your key measures is yield loss. This is measured as a percent, and represents the percent (by weight) of widgets that get scrapped at the end of the process due to various quality and production issues. The percent scrap is measured daily, with monthly data (average) used for tracking purposes. Historically, your percent scrap has been around 4%, which executive manager states is too high. You have been asked to investigate the yield loss and to initiate a program to reduce this loss. Your first step is to develop a process behavior chart. The monthly data for the past 24 months is in the Excel file provided. Develop a process behavior chart for yield loss, critique and state your improvement actions. Make all necessary changes to the chart based on special causes. State what your current process yield is (in process behavior terms: min, max and average). One note: A new widget making machine was installed Oct 1, 2018.

Month	Yield Loss (%)
Jun-17	3.74
Jul-17	4.8
Aug-17	3.51
Sep-17	3.48
Oct-17	4.31
Nov-17	4.99
Dec-17	4.03
Jan-18	4.5
Feb-18	4.26
Mar-18	4.18
Apr-18	3.47
May-18	3.78
Jun-18	4.33
Jul-18	4.05
Aug-18	3.9
Sep-18	4.18
Oct-18	3.81
Nov-18	3.88
Dec-18	3.85
Jan-19	3.62
Feb-19	3.71
Mar-19	3.83
Apr-19	3.66
May-19	3.79

Answer 1

Month	Yield Loss (%)
Jun-17	3.74
Jul-17	4.8
Aug-17	3.51
Sep-17	3.48
Oct-17	4.31
Nov-17	4.99
Dec-17	4.03
Jan-18	4.5
Feb-18	4.26
Mar-18	4.18
Apr-18	3.47
May-18	3.78
Jun-18	4.33
Jul-18	4.05
Aug-18	3.9
Sep-18	4.18
Oct-18	3.81
Nov-18	3.88
Dec-18	3.85
Jan-19	3.62
Feb-19	3.71
Mar-19	3.83
Apr-19	3.66
May-19	3.79

Min	3.47
Average	3.99
Max	4.99

Historically, your percent scrap has been around 4%

Conclusion:

Need to find out rootcause analysis in month of red Highlighted

since a new widget making machine was installed Oct 1, 2018 after that process is runnin proper anf below the historiacal % scrap 4%.