My slides for the Ritz case.

1. Homework 3 – Ritz Carlton
Question 1

2. Ritz Service Defects P-Chart
0.0350
0.0300
0.0250
0.0200
0.0150
0.0100
0.0050
-
1-Jan-97 1-Feb-97 1-Mar-97 1-Apr-97 1-May-97 1-Jun-97 1-Jul-97 1-Aug-97 1-Sep-97 1-Oct-97 1-Nov-97
Average Defect %
UCL *Denominator for % defects is occupancy; essentially
Daily Defect % assuming a maximum of 1 defect per occupant

3. Notably Defective Days
% defects
ph not answr
wake-up call
want double
res incorrec
newspaper
Deviation
rm assign
check-out
Standard
want king
msg light
rm clean
rm delay
check-in
Totals
UCL
Date Day of week Occupancy
7-Jan-97 Tuesday 442 4 4 1 9 0.020 0.003 0.012
12-Jan-97 Sunday 277 2 1 4 1 8 0.029 0.004 0.014
14-Jan-97 Tuesday 442 1 1 2 2 1 7 0.016 0.003 0.012
15-Jan-97 Wednesday 470 1 1 2 2 1 7 0.015 0.003 0.012
17-Feb-97 Monday 359 2 1 1 1 5 0.014 0.003 0.013
12-Mar-97 Wednesday 470 14 1 15 0.032 0.003 0.012
20-Apr-97 Sunday 277 3 3 6 0.022 0.004 0.014
27-Apr-97 Sunday 277 2 1 1 1 5 0.018 0.004 0.014
15-May-97 Thursday 470 1 4 1 1 7 0.015 0.003 0.012
4-Jul-97 Friday 525 2 1 2 2 2 1 10 0.019 0.003 0.011
13-Jul-97 Sunday 277 2 2 1 5 0.018 0.004 0.014
25-Sep-97 Thursday 470 3 3 1 7 0.015 0.003 0.012
1-Oct-97 Wednesday 470 1 3 3 7 0.015 0.003 0.012
7-Nov-97 Friday 525 1 1 1 3 1 7 0.013 0.003 0.011
Totals: 5751 6 3 0 0 17 21 13 25 6 9 4 1 105
• Chart above shows days when % defects exceeded the upper control limit (UCL)
• Most numerous defects on these days:
– Reservation Incorrect  14 defects on 12 March 1997
– Room Assignment
– Room Clean  Present consistently in notably defective days
– Phone not Answered