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