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
Make Candy
Make Candy
Mix
Package
Put in big bags
Wrong wt.
Wrong wt.
Make Candy
Mix %
Make Candy
Make Candy
Candy irregularity
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 colors
1.
2.
3.
4.
5.
6.
7.
Write Name on form
Write weight on form
Write Package # on form
Count # of each color and
write on form
Count total # of candies
and write on form
(Advanced only): Eat
candies
Turn in forms and
complete wrappers
Your Job

Write down package #



Optional:





Weigh package and candies, all together, in grams and
ounces
Write down weights on form
Open package, count total # candies
Count # of each color
Write down
Eat candies
Turn in form and empty complete wrappers for
weighing
Grams or Ounces?
The effects of rounding
25.00
0.80
24.00
g - rounded
oz - rounded
23.00
0.7 Ounces
0.70
Rounded Weight - Ounces
Rounded Weight - grams
22.00
21 grams
21.00
20 grams
20.00
0.6 Ounces
0.60
19 grams
19.00
18 grams
18.00
17.00
0.50
14.5
15.0
15.5
16.0
16.5
17.0
17.5
18.0
18.5
19.0
Original Weight in grams
19.5
20.0
20.5
21.0
21.5
22.0
22.5
Peanut Candy Weights
Avg. 2.18, stdv 0.242, c.v. = 0.111
Peanut Individuals
9
8
7
6
Count

5
4
3
2
1
0
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
Mass (g)
2.4
2.5
2.6
2.7
2.8
2.9
3
Plain Candy Weights
Avg 0.858, StDev 0.035, C.V. 0.0413
Individual Plain Candies
16
14
12
10
8
6
4
2
0
0.
78
0.
79
0.
8
0.
81
0.
82
0.
83
0.
84
0.
85
0.
86
0.
87
0.
88
0.
89
0.
9
0.
91
0.
92
0.
93
0.
94
0.
95
0.
96
0.
97
Count

Mass (g)
Mini Candy Weights
Avg 0.288, StDev 0.020, C.V. 0.070

M&M Mini Individual Candy Weights
30%
25%
Percentage
20%
15%
10%
5%
0%
0.23
0.24
0.25
0.26
0.27
0.28
0.29
Weight (in grams)
0.3
0.31
0.32
0.33
0.34
Peanut Color Mix






Brown 17.7%
Yellow 8.2%
Red
9.5%
Blue 15.4%
Orange 26.4%
Green 22.7%
website
20%
20%
20%
20%
10%
10%
Plain Color Mix






Brown
Yellow
Red
Blue
Orange
Green
Class
12.1%
14.7%
11.4%
19.5%
21.2%
21.2%
website
30%
20%
20%
10%
10%
10%
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?
264.8g /36g = 7.35 servings
267.9g /45g = 5.95 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
25%
20%
15%
10%
5%
0%
15
15.5
16
16.5
17
17.5
18
18.5
19
19.5
10.9% of sample below 16.2g!
20
20.5
21
21.5
22
22.5
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