candy capability operations management dr. ron lembke
TRANSCRIPT
Candy Capability
Operations Management
Dr. Ron Lembke
Tolerance Limits for food? Underfilling who
would notice? Overfilling – would
anyone care?
Packaged Goods What are the Tolerance Levels? What we have to do to measure capability? What are the sources of variability?
Production Process
Make Candy
Package Put in big bagsMake Candy
Make Candy
Make Candy
Make Candy
Make Candy
Mix
Mix %
Candy irregularity
Wrong wt. Wrong wt.
Weighing Package and all candies Before placing candy
on scale, press “ON/TARE” button
Wait for 0.00 to appear If it doesn’t say “g”,
press Cal/Mode button a few times
Write weight down on form
Candy colors1. Write Name on form
2. Write weight on form
3. Write Package # on form
4. Count # of each color and write on form
5. Count total # of candies and write on form
6. (Advanced only): Eat candies
7. Turn in forms and complete wrappers
Your Job Write down package #
Weigh package and candies, all together, in grams and ounces
Write down weights on form Optional:
Open package, count total # candies Count # of each color Write down Eat candies
Turn in form and empty complete wrappers for weighing
The effects of rounding
17.00
18.00
19.00
20.00
21.00
22.00
23.00
24.00
25.00
14.5 15.0 15.5 16.0 16.5 17.0 17.5 18.0 18.5 19.0 19.5 20.0 20.5 21.0 21.5 22.0 22.5
Original Weight in grams
Ro
un
de
d W
eig
ht
- g
ram
s
0.50
0.60
0.70
0.80
Ro
un
de
d W
eig
ht
- O
un
ce
s
g - rounded
oz - rounded 0.7 Ounces
20 grams
0.6 Ounces
19 grams
18 grams
21 grams
Grams or Ounces?
Peanut Candy Weights Avg. 2.18, stdv 0.242, c.v. = 0.111
Peanut Individuals
0
1
2
3
4
5
6
7
8
9
1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3
Mass (g)
Co
un
t
Plain Candy Weights Avg 0.858, StDev 0.035, C.V. 0.0413
Individual Plain Candies
0
2
4
6
8
10
12
14
16
Mass (g)
Co
un
t
Mini Candy Weights
0.23 0.24 0.25 0.26 0.27 0.28 0.29 0.3 0.31 0.32 0.33 0.340%
5%
10%
15%
20%
25%
30%
M&M Mini Individual Candy Weights
Weight (in grams)
Per
cent
age
Avg 0.288, StDev 0.020, C.V. 0.070
Peanut Color Mix website
Brown 17.7% 20% Yellow 8.2% 20% Red 9.5% 20% Blue 15.4% 20% Orange 26.4% 10% Green 22.7% 10%
Classwebsite
Brown 12.1% 30% Yellow 14.7% 20% Red 11.4% 20% Blue 19.5% 10% Orange 21.2% 10% Green 21.2% 10%
Plain Color Mix
So who cares? Dept. of Commerce National Institutes of Standards & Technology NIST Handbook 133 Fair Packaging and Labeling Act
NIST Fines
Don’t get caught It’s embarassing You’ll look dumb
How Many Servings?
267.9g /45g = 5.95 servings
264.8g /36g = 7.35 servings
Not for Retail Sale
Why Not?• Ingredients• Nutritional information• Peanut/allergy information• Need room for cute pics• Process variability?
Acceptable?
Sampling Plans for Category A
Package Weight “Not Labeled for Individual Retail Sale” If individual is 18g MAV is 10% = 1.8g Nothing can be below 18g – 1.8g = 16.2g
Too Much Variability
15 15.5 16 16.5 17 17.5 18 18.5 19 19.5 20 20.5 21 21.5 22 22.50%
5%
10%
15%
20%
25%
10.9% of sample below 16.2g! Avg= 17.57, stdev 1.42
Suppose they wanted to Stated weight = 18g, MAV = 16.2g Suppose want 99.7% chance nothing below MAV Set the average to be 3σ above MAV
σ = 1.42g, so set Avg = 16.2 + 3*1.42 = 20.46 You pay for 18g, they give you 20.46g! 13.7% Free! They have to give away 1/7th of the
candy! Clearly, they aren’t going to do this!
Summary Many reasons M&M’s “Not for Individual
Sale” Process variability seems to be an important
one, if not the major one Process variability is a very important
consideration for companies. BTW, one bag was 223.6g < 264.8