task 1: fundamentals of mathematical statistics (20 … · task 1: fundamentals of mathematical...

Quality Management Exam 2011/07/26 of 41

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St.-ID no. :

Points :

Task 1: Fundamentals of mathematical statistics (20 points)

You are quality manager of a company called SOCCGO that produces soccer goals for the FIFA

women’s world cup 2011 in Germany. After the first matches of the tournament have been

played, you are informed that many players have severe trouble scoring. This leads to the

undesirable fact that more and more spectators are losing interest in this great sports event. You

assume that the space between the goalposts might be too small and you want to examine if this

is actually the cause of the difficulties (picture 1-1). Since you are not able to measure every

single goal you want to take a sample out of your current production. However, before taking the

sample, you need to explain some basics of statistics.

b

Picture 1-1: Space between goalposts

1.1 Basics of statistics (5.5 points)

Please describe the different types of statistics. Complete table 1-1.


Name :

St.-ID no. :

Points :

Table 1-1: Different types of statistics

Type of statistics Description

A Descriptive

statistics

B Inductive

statistics

Please sketch the distribution function F(x) corresponding to the probability density function of a

normal distribution f(x) shown in picture 1-2.

y y

x xf(x) F(x)

Picture 1-2: Normal distribution

Deming’s experiment illustrates the statistical spread of measured data. Using the experimental

setup shown in picture 1-3 a ball is thrown through the funnel onto a sticky board, which the ball

adheres to. The objective is to hit the center of the hairline cross which is painted on the board.

To this end, the distance between the ball (which got stuck on the board) and the center of the

hairline cross will be measured in x- and y-direction. The experimental setup is then readjusted in

accordance with these measurements, so as to improve accuracy. The experiment can be

executed in two different ways.


Name :

St.-ID no. :

Points :

Picture 1-3: Deming’s experiment

Experiment A: The x- and y-distance from the ball to the center of the hairline cross is measured

after each throw and the experimental setup will also be readjusted after each throw.

Experiment B: 10 balls in a row are thrown through the funnel without moving the experimental

setup. After the 10 balls have landed on the board and gotten stuck on it, the distance from each

ball to the target is measured in the x- and y-directions. Afterwards, the mean of the x- and y-

distances is calculated and the experimental setup is readjusted. Thus, the experimental setup is

readjusted after n throws.

Explain the influence of the two different experimental setups on the spread/standard deviation

of the measured data within the experiment (table 1-2).


Name :

St.-ID no. :

Points :

Table 1-2: Influence of the different experimental setups

Experiment Influence on the spread of the measured data

A

B

Why does it make more sense not to readjust a process immediately after each measurement?

Answer:


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St.-ID no. :

Points :

1.2 Calculation of the variance and the standard deviation (3.5 points)

You are now aware of the fundamentals of statistics. In the next step, you take a sample of 12

soccer goals out of the current production. Please calculate the variance and the standard

deviation of this sample and write down the formulas used. You can find the measured widths

of the goals in table 1-3.

Note: The sample follows a normal distribution. Please round the results to integers.

Table 1-3: Measured widths of the goals

Goal [n] Space between

the goalposts

[mm]

1 7000

2 7283

3 7673

4 7750

5 7079

6 7251

7 7050

8 7205

9 7458

10 7600

11 7200

12 7250


Name :

St.-ID no. :

Points :

Space for your calculations:


Name :

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Points :

1.3 Histograms (4 points)

The data has to be presented within a graphic. In order to create a histogram, you need to know

the number of classes (k), the class limits (the range) and the absolute frequency. Please fill in

table 1-4 (the number of classes may differ from the number of lines in table 1-4). For the

calculation of the number of classes, please round down to the nearest integer. Please round the

result of the class width to integers. Please mark the limits of the classes clearly. The classes

must not overlap.

Hint: k

xxH

)( width Class minmax −==

Table 1-4: Data needed to create a histogram

Class no. Class limits (range) Absolute frequency

Furthermore, calculate the median of the individual values and the mode for the classes and

round these, if necessary, to one decimal place. Complete table 1-5.

Table 1-5: Median and mode

Median

Mode


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St.-ID no. :

Points :

1.4 Confidence intervals (3 points)

Please calculate the confidence interval for the mean (average) with a 5 % probability of error for

a two-sided test using the values calculated in 1.2. In case you were not able to solve task 1.2,

please use the following values for the next tasks:

Use the distribution function according to table 1-6 in the appendix of task 1 and the following

formula for your calculations:

Hint : Round the intermediary results and the final result to integers.

There are different influences on the size of the confidence interval. Please fill in the blanks:

A) The smaller the sample, the the size of the confidence interval.

B) The larger the probability of error, the the size of the confidence interval.

n

stxµ

n

stx

αn

αn

21;1

21;1 −−−−

+≤≤−

220s ,7500x ==


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Points :

1.5 Sample size (4 points)

You want to analyze if the sample size used is sufficiently large to make a significant statement

about the process. Calculate the necessary sample size under the assumption of a t-distribution

with 90 % confidence and a demanded accuracy of 90 mm.

Please note that a two-sided test is needed.

Hint :

2

21;1

*

∆=

−−

µ

α

α

st

nn

Is the current sample size sufficient?

Answer:

Reason:


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St.-ID no. :

Points :

Table 1-6: Distribution function of the t-distributions

1-αn 0,6 0,8 0,9 0,95 0,975 0,995 0,999 0,9995

1 0,325 1,376 3,078 6,314 2,447 63,657 318,309 636,6192 0,289 1,061 1,886 2,920 4,303 9,925 22,327 31,5993 0,277 0,978 1,638 2,353 3,182 5,841 10,215 12,9244 0,271 0,941 1,533 2,132 2,776 4,604 7,173 8,6105 0,267 0,920 1,476 2,015 2,571 4,032 5,893 6,8696 0,265 0,906 1,440 1,943 2,447 3,707 5,208 5,9597 0,263 0,896 1,415 1,895 2,365 3,499 4,785 5,4088 0,262 0,889 1,397 1,860 2,306 3,355 4,501 5,0419 0,261 0,883 1,383 1,833 2,262 3,250 4,297 4,781

10 0,260 0,879 1,372 1,812 2,228 3,169 4,144 4,58711 0,260 0,876 1,363 1,796 2,201 3,106 4,025 4,43712 0,259 0,873 1,356 1,782 2,179 3,055 3,930 4,31813 0,259 0,870 1,350 1,771 2,160 3,012 3,852 4,22114 0,258 0,868 1,345 1,761 2,145 2,977 3,787 4,14015 0,258 0,866 1,341 1,753 2,131 2,947 3,733 4,07316 0,258 0,865 1,337 1,746 2,120 2,921 3,686 4,01517 0,257 0,863 1,333 1,740 2,110 2,898 3,646 3,96518 0,257 0,862 1,330 1,734 2,101 2,878 3,610 3,92219 0,257 0,861 1,328 1,729 2,093 2,861 3,579 3,88320 0,257 0,860 1,325 1,725 2,086 2,845 3,552 3,85021 0,257 0,859 1,323 1,721 2,080 2,831 3,527 3,81922 0,256 0,858 1,321 1,717 2,074 2,819 3,505 3,79223 0,256 0,858 1,319 1,714 2,069 2,807 3,485 3,76824 0,256 0,857 1,318 1,711 2,064 2,797 3,467 3,74525 0,256 0,856 1,316 1,708 2,060 2,787 3,450 3,72526 0,256 0,856 1,315 1,706 2,056 2,779 3,435 3,70727 0,256 0,855 1,314 1,703 2,052 2,771 3,421 3,69028 0,256 0,855 1,313 1,701 2,048 2,763 3,408 3,67429 0,256 0,854 1,311 1,699 2,045 2,756 3,396 3,65930 0,256 0,854 1,310 1,697 2,042 2,750 3,385 3,646

z 0,253 0,842 1,282 1,645 1,96 2,576 3,09 3,291

1-αn 0,6 0,8 0,9 0,95 0,975 0,995 0,999 0,9995

1 0,325 1,376 3,078 6,314 2,447 63,657 318,309 636,6192 0,289 1,061 1,886 2,920 4,303 9,925 22,327 31,5993 0,277 0,978 1,638 2,353 3,182 5,841 10,215 12,9244 0,271 0,941 1,533 2,132 2,776 4,604 7,173 8,6105 0,267 0,920 1,476 2,015 2,571 4,032 5,893 6,8696 0,265 0,906 1,440 1,943 2,447 3,707 5,208 5,9597 0,263 0,896 1,415 1,895 2,365 3,499 4,785 5,4088 0,262 0,889 1,397 1,860 2,306 3,355 4,501 5,0419 0,261 0,883 1,383 1,833 2,262 3,250 4,297 4,781

10 0,260 0,879 1,372 1,812 2,228 3,169 4,144 4,58711 0,260 0,876 1,363 1,796 2,201 3,106 4,025 4,43712 0,259 0,873 1,356 1,782 2,179 3,055 3,930 4,31813 0,259 0,870 1,350 1,771 2,160 3,012 3,852 4,22114 0,258 0,868 1,345 1,761 2,145 2,977 3,787 4,14015 0,258 0,866 1,341 1,753 2,131 2,947 3,733 4,07316 0,258 0,865 1,337 1,746 2,120 2,921 3,686 4,01517 0,257 0,863 1,333 1,740 2,110 2,898 3,646 3,96518 0,257 0,862 1,330 1,734 2,101 2,878 3,610 3,92219 0,257 0,861 1,328 1,729 2,093 2,861 3,579 3,88320 0,257 0,860 1,325 1,725 2,086 2,845 3,552 3,85021 0,257 0,859 1,323 1,721 2,080 2,831 3,527 3,81922 0,256 0,858 1,321 1,717 2,074 2,819 3,505 3,79223 0,256 0,858 1,319 1,714 2,069 2,807 3,485 3,76824 0,256 0,857 1,318 1,711 2,064 2,797 3,467 3,74525 0,256 0,856 1,316 1,708 2,060 2,787 3,450 3,72526 0,256 0,856 1,315 1,706 2,056 2,779 3,435 3,70727 0,256 0,855 1,314 1,703 2,052 2,771 3,421 3,69028 0,256 0,855 1,313 1,701 2,048 2,763 3,408 3,67429 0,256 0,854 1,311 1,699 2,045 2,756 3,396 3,65930 0,256 0,854 1,310 1,697 2,042 2,750 3,385 3,646

z 0,253 0,842 1,282 1,645 1,96 2,576 3,09 3,291


Name :

St.-ID no. :

Points :

Task 2: Quality in the early phases – focus product (20 points)

You’ve just started your job as an engineer in the product development department of Worldcar

Corp., an automotive OEM, which is right now focussing on electric mobility and the future of

the automobile. To leave a good impression with your supervisor, you start off with some well-

meant advice concerning the importance and accomplishments of quality management in the

early phases of product development.

As you remember from your studies, customer orientation is the key for the development of

successful products. For this purpose, the knowledge of customer requirements and wishes, the

solution of conflicts within construction as well as the prioritization of tasks are essential.

Moreover, an early elimination of constructive and manufacturing-based risks saves costs.

2.1 Balancing targets and risks in product development (15 points)

Worldcar Corp. plans the introduction of a new electric car for 2014. As several OEMs plan to

develop and release electric cars within the next years, the market will be highly competitive and

differentiation counts. To stand out from the competition Worldcar Corp. is collecting ideas for

additional product features. These are

- AAA-slots for common batteries to go some extra miles,

- pedals as a “range-extender”,

- candles as an battery-saving alternative for display lighting and the cigarette lighter, and

- hiking boots as a give-away, if the battery runs out.


Name :

St.-ID no. :

Points :

The targets, which Worldcar Corp. pursues with each of its products, shall also apply to the new

product generation. Therefore, the products shall

- attract attention,

- have a dynamic appearance,

- carry a low risk of injuries, for the user as well as bystanders and

- bear low production costs which can be passed on to the customer.

In a first step, these targets are to be ranked using a pairwise comparison. Please calculate the

absolute and relative rankings of the targets in table 2-1. Please write down the necessary

formula for the relative ranking at least once and use a 1 to 5 scale (round to whole numbers)

[You will find space for your calculations on the last page of this task.].

Table 2-1: Pairwise comparison of targets

Attracting attention

Dynam

ic appearance

Low risk of injuries

Low production costs

Absolute ranking

Relative ranking

Attracting Attention X 0 0 1

Dynamic appearance 2 X 0 1

Low risk of injuries 2 2 X 1

Low production costs 1 1 1 X

2 - more important than1 - as important as0 - less important than

Formula: ___________________________________________________________________


Name :

St.-ID no. :

Points :

Beside the targets, there are also entrepreneurial risks attached to each new product development.

Worldcar Corp. identified three main risks for their product ideas:

- Time-to-Market: Due to high production volumes and the associated efforts for

distribution, the development as well as function and acceptance tests must be completed

in time.

- Feasibility: The new products of Worldcar Corp. must be simple and must employ - but

not exceed - the company’s development resources.

- Bad for business: The products must not be bad for the company’s image or reputation.

Please calculate and write down the absolute and relative rankings of the risks in table 2-2.

Please use a 1 to 5 scale for the relative ranking (round to whole numbers) [You will find space

for your calculations on the last page of this task.].

Table 2-2: Pairwise comparison of risks

Time-to-M

arket

Feasibility

Bad for business

Absolute ranking

Relative ranking

Time-to-Market X 0 0

Feasibility 2 X 0

Bad for business 2 2 x

2 - more important than1 - as important as0 - less important than


Name :

St.-ID no. :

Points :

In a next step, the product ideas are to be evaluated by the ranked targets and risks. Please copy

your relative rankings from tables 2-1 & 2-2 to table 2-3 and calculate the individual absolute

and relative ranking of targets and risks for the product ideas in table 2-3. For the relative

ranking, please use a 1 to 10 scale (round to whole numbers) [You will find space for your

calculations on the last page of this task.].

If you haven’t been able to solve the prior tasks, please use the following rankings:

Targets: Ranking: Risks: Ranking:

Attracting attention 2 Time-to-Market 5

Dynamic appearance 1 Feasibility 3

Low risk of injuries 3 Bad for business 1

Low production costs 5


Name :

St.-ID no. :

Points :

Table 2-3: Evaluation of product ideas

Targets/Risks Ideas

Relative ranking

AA

A-S

lots

Pedals

Candles

Hiking boots

Targets

Attracting attention

Dynamic appearance

Low risk of injuries

Low production costs

Risks

Time-to-Market

Feasibility

Bad for business

Absolute ranking Targets

Relative ranking Targets

Absolute ranking Risks

Relative ranking Risks

Legend: = 1

= 3

= 9

Worldcar Corp. knows that it is crucial to contrast targets with risks and focus development

resources on those product ideas that have the best ratio of targets and risks and to avoid high

risks.

One possibility to do that is to depict both targets and risks in a portfolio. Please position the

product ideas in the portfolio in picture 2-1 with the help of the targets/risks evaluation from

table 2-3.


Name :

St.-ID no. :

Points :

0 5 10

5

10

?

Targ

ets

Risks

Picture 2-1: Targets/risks-portfolio

According to the portfolio in picture 2-2, which product idea should not be realized by Worldcar

Corp.?

Answer: ______________________________________


Name :

St.-ID no. :

Points :

2.2 Over- and under-fulfillment of quality expectations (5 points)

During the planning of product quality it is essential to fulfill the customer’s expectations and

requirements as precisely as possible to increase the value of the product for the customer. To

dimension a certain quality characteristic of a product it is important to consider the specific

grades of expectations. For dimensioning the velocity of an electric car, the intended field of use

is important. Please plot in the given diagram (picture 2-2) an exemplary value function for both

a “town car” and a “sports car” regarding their velocity. Label the graphs and mark the areas

of over-fulfillment and under-fulfillment (non-conformance).

100%

150%

50%

Value

Velocity

Picture 2-2: Grades of customer expectations

Which effect does an under-fulfillment resp. an over-fulfillment have concerning the value for

the customer?

Under-fulfillment: ________________________________________________________

_______________________________________________________________________

Over-fulfillment: _________________________________________________________

_______________________________________________________________________


Name :

St.-ID no. :

Points :

Space for your calculations:


Name :

St.-ID no. :

Points :

Task 3: Quality in the early phases – focus deviation (20 points)

3.1 FMEA (8 points)

The objective of performing an FMEA is to reveal potential failures during the development of a

product or new production method at the planning stage and to initiate appropriate action to

avoid them.

Name the formula to calculate the risk priority number (RPN). (1 point)

____________________________________________________________________

Name all possible measures for risk minimization and the corresponding risk number (RnX).

Table 3-1: Measure types for FMEA

Measure type Risk number

(0.5 points for each correct entry)

Which measure would you choose in the given example? (1 point)

Table 3-2: Risk numbers

RNA RNS RND

2 4 8

____________________________________________________________________


Name :

St.-ID no. :

Points :

As a consequence of the FMEA, the numbers of occurring failures of specific products (positions

1 to 5 in table 3-3) were counted. This data is to be used for a Pareto analysis. Calculate the

missing values (one decimal place) and insert them into the table. (1 point)

Table 3-3: Analysis of failure numbers

Position Number Number of

failures

[%] Sum [%]

1 2 200

2 1 140

3 5 80

4 4 35

5 3 15

470

Transfer the calculated values from the table into the Pareto diagram below. (1 point)

______

90

80

70

60

40

30

20

10

100

50

0Nr. ________________________

Picture 3-1: Pareto analysis

No.


Name :

St.-ID no. :

Points :

Choose the products for which – based on the Pareto analysis – measures have to be initiated.

Mark each chosen number with a cross in the table below. (1 point)

Table 3-4: Products

No. 1 No. 2 No. 3 No. 4 No. 5

3.2 Definitions and terms for methods of quality assurance before start of serial production (12 points)

a) (4 points)

Quality Management includes several methods and tools to ensure a high-quality standard prior

to the start of serial production (SOP), e.g. Quality Assessment and Fault Tree Analysis. Define

both methods and write down the required goals.

Method: Quality Assessment

Definition: __________________________________________________________________

__________________________________________________________________

__________________________________________________________________

Goal: 1. ________________________________________________________________

__________________________________________________________________

Method: Fault Tree Analysis

Definition: __________________________________________________________________

__________________________________________________________________

__________________________________________________________________


Name :

St.-ID no. :

Points :

Goals: 1. ________________________________________________________________

2. ________________________________________________________________

3.________________________________________________________________

b) (5 points)

There are different types of Design Reviews corresponding to different phases and items.

Complete the table according to picture 3-2.

Finalize

functional spec.Decision for

a draftRelease of prototype

Series

Release of series

Definition

Project start

Usage

DR:

Item:

SD

R

CD

R

MD

R1

2

3

4

5

6

7

8

910

Picture 3-2: Phases and items of types of Design Reviews


Name :

St.-ID no. :

Points :

1

2 Functional spec.

3 Development

4 Lab sample (component)

5

6 Prototype

7

8

9 Pilot lot

10

c) (3 points)

Name the three steps of a Quality Assessment and the respective review item. (3 points)

Table 3-5: Steps of the QA

Name of the step Review item

QA 1

QA 2

QA 3

(0.5 points for each correct entry)


Name :

St.-ID no. :

Points :

Task 4: Quality Management in Procurement (20 points)

4.1 Procurement strategies (3 points)

In procurement, portfolios are used to choose the procurement strategy for different products and

suppliers. The portfolio shown below displays the different types of suppliers and procured

goods. Please fill in the missing strategies (1 to 3). (3 points)

Strategicgoods

Leveragegoods

Bottleneck-goods

Standardgoods

Standardsources

Bottleneck-sources

Leveragesources

Strategicsources

Displacement1.

2.

Using market potential,then cooperation in

partnership

3.Supplier development or

displacement to strategic orleverage sources

Picture 4-1: Portfolio of different types of suppliers and procured goods

1: ___________________________________________________________________________

2: ___________________________________________________________________________

3: ___________________________________________________________________________


Name :

St.-ID no. :

Points :

4.2 Procurement and supply strategies (8 points)

Please name one quality advantage and three quality disadvantages for the procurement and

supply strategies listed below.

Single & Local Sourcing (4 points)

Quality advantage for the procuring company:

1: ___________________________________________________________________________

Quality disadvantages for the procuring company:

1: ___________________________________________________________________________

2: ___________________________________________________________________________

3: ___________________________________________________________________________

Just in Sequence (4 points)

Quality advantage for the procuring company:

1: ___________________________________________________________________________

Quality disadvantages for the procuring company:

1: ___________________________________________________________________________

2: ___________________________________________________________________________

3: ___________________________________________________________________________


Name :

St.-ID no. :

Points :

4.3 Continuous supplier assessment (9 points)

The company Jazz-Ing produces guitars and procures the strings from the supplier R&B

Productions. The suppliers are assessed by the given categories in picture 4-2. Picture 4-3

shows the structure for the sub-category “Procurement” and picture 4-4 the structure for the sub-

category “Quality”.

Procurement Quality Logistics Technology

Price Quality performanceLogisticsperformance

Current technology position

Initiative for costreduction

QM system Logistics systemCompliance withrequirements

Soft facts

Cooperation

RMAmanagement70 40

603080

2010

9085

15

40 30 20 5 5

Proportion in total index

Proportion in sub area index(here: technology)

Picture 4-2: Categories for the continuous supplier assessment

Price

In comparison withtarget value

In comparison withother suppliers

Tendency

Price < 85% thantarget

Price 86 to 90% from target


Price 96 to 100 % from target65

25

10Initiative for cost

reduction

100

95

90

80

85

15

Part of theevaluation

Procurement

Part on theevaluation

Price

Absolutepercentage

on the lowestlevel

> 5% cheaper thanother suppliers

+/- 5% of othersuppliers

100

90

> 5% higher thanother suppliers

60

Price

In comparison withtarget value

In comparison withother suppliers

Tendency

Price < 85% thantarget



Price 96 to 100 % from target65

25

10Initiative for cost

reduction

100

95

90

80

85

15

Part of theevaluation

Procurement

Part on theevaluation

Price

Absolutepercentage

on the lowestlevel

> 5% cheaper thanother suppliers

+/- 5% of othersuppliers

100

90

> 5% higher thanother suppliers

60

Picture 4-3: Sub-category „Procurement“ for the continuous supplier assessment


Name :

St.-ID no. :

Points :

Quality performanceRecognized failures

in assembly

Field failures of brought-in parts

80

20QM-system

90

10

Picture 4-4: Sub-category „Quality“ for the continuous supplier assessment

Please conduct an assessment of the supplier R&B Productions in the sub-categories

“Procurement” and “Quality” for the 4th quarter of the year. To this end, the following

information is available:

- The average price of strings on the market is 30 cents.

- R&B Productions offers the strings for 25 cents.

- The target price for the strings is 28 cents.

- The price tendency of R&B Productions was rated 96%.

- The initiative for cost reduction was rated 100%.

- Soft facts were rated 99%.

- The category technology was rated 95%.

- The category logistics was rated 99%.

- In the 4th quarter of the year 20,000 strings were delivered and assembled.

- One string was detected to be defect already during assembly.

- The QM-System of R&B Productions was rated 95%.

Further information is contained in pictures 4-5 to 4-7:


Name :

St.-ID no. :

Points :

recognized failures during assembly[ppm]

degree ofperformance

[%]

10090

80

7060

5040

30

2010

0 100 200 300 500 600 700 800 1000900400

ppm = parts per million

Recognized failures during assembly from the 4th quarter

recognized failures during assembly[ppm]

degree ofperformance

[%]

10090

80

7060

5040

30

2010

0 100 200 300 500 600 700 800 1000900400


Recognized failures during assembly from the 4th quarter

Picture 4-5: Recognized failures during assembly in the 4th quarter

Field failures of procured parts

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

5

1.Quarter

2.Quarter

3.Quarter

4.Quarter

R&BProductionsMusicFactoryString AG

Nu

mb

ero

f fi

eld

failu

res

Picture 4-6: Field failures of procured parts


Name :

St.-ID no. :

Points :

Field failure evaluation of procured parts from the 4th quarter

field failures[ppm]

deg

ree

of

per

form

ance

[%]

10090

80

7060

5040

30

2010

0 200 400 600 1000800


Picture 4-7: Field failure evaluation of procured parts in the 4th quarter

Key performance index for “Procurement”:

Calculation of the sub-category “Price“ (3 points):

Calculation of the sub-category “Initiative for cost reduction“ (1 point):


Name :

St.-ID no. :

Points :

Final calculation of the category “Procurement” (1 point):

Key performance index for “Quality”:

Calculation of the sub-category “Quality performance“ (2 points):

Calculation of the sub-category “QM system“(1 point):

Final calculation of the category “Quality” (1 point):


Name :

St.-ID no. :

Points :

Task 5: Quality programs and quality management systems (20 points)

5.1 Quality management and standards (6 points)

The DIN EN ISO 9000 ff. is the most popular series of standards for quality management

systems. Please name the three essential standards (0.5 points each) and give short explanations

of their content in table 5-1 (0.5 points each):

Table 5-1: The three essential standards of the DIN EN ISO 9000 ff. series of standards

Name Content DIN EN ISO

DIN EN ISO

DIN EN ISO

The DIN EN ISO 9000 contains eight quality management principles which can be used by

management to improve the performance of an organization. Please name six (0.5 points each; 3

points max.) of the eight principles (table 5-2):

Table 5-2: The principles of quality management

1

2

3

4

5

6


Name :

St.-ID no. :

Points :

5.2 Process-based quality management (4 points)

The basis of the DIN EN ISO 9001 is a process model, which brings the elements of a quality

management system into a structured context. Please complete the model of process-based

quality management (picture 5-1) by naming the numbered fields in table 5-3 (0.5 points each):

Customers

Customers

7.

2. 4.

8. 5.

1.

3.

6.

Input

Output

Source: ISO 9001Value added

Information

Picture 5-1: Process model of DIN EN ISO 9001

Table 5-3: Elements of the DIN EN ISO 9001 process model 1

2

3

4

5

6

7

8


Name :

St.-ID no. :

Points :

5.3 Process-Structure-Matrix (7 points)

After finishing your studies you got a job as project manager at a famous dockyard in Hamburg.

The company supplies custom-built sailing-boats and has established itself as a well-known

contract manufacturer in its sector. Unfortunately, there have been some complaints due to late

deliveries in the recent past. In order to prevent image damage and a decline in sales,

management wants to analyze the interfaces in the business process. Your superior asks you to

present the entire process graphically. You decide to map the process using a Process-Structure-

Matrix. For your preparations, you receive the following process description:

In the beginning, the sales department advises the customer. Afterwards, the order is entered into

the system by a sales manager and the production manager is informed about the new order. He

informs the sales department about the estimated start of production as well as its completion

taking the current capacity utilization into account. The sales department passes the information

concerning the date of completion on to the delivery department. There, the date for delivery is

determined. Concurrently, the purchasing department uses the data from the sales department to

order the needed parts from suppliers. These are then checked by the stock receipt. Defects are

reported back to the purchase department to allow for supplier assessment. Checked parts are

made available to the production department, which starts manufacturing the customized sailing-

boat. Finally, the completed sailing-boat is handed over to the customer in a festive ceremony by

the delivery department.

The following chart (picture 5-2) shows the process described above with its sub-processes and

their respective interfaces:


Name :

St.-ID no. :

Points :

Picture 5-2: Depiction of the sub-processes and their interfaces

Please complete the Process-Structure-Matrix by filling in the missing sub-processes. Please

regard the logical order. Extract the necessary information from the process description on the

preceding page and the picture above. Then, please clearly mark the appropriate fields that show

the interfaces of the sub-processes according to the chart above with an X (picture 5-3):

Picture 5-3: Process-Structure-Matrix


Name :

St.-ID no. :

Points :

For each correctly answered line in the Process-Structure-Matrix you receive 1 point. Lines filled

out incorrectly receive 0 points.

5.4 Multiple choice (3 points)

Please check the following statements in picture 5-4 for correctness and show your decision

clearly by marking the appropriate field with a cross. Each correct answer leads to 0.5 points,

incorrect as well as no answers lead to 0 points.

Correct?

yes no

1 The DIN EN ISO 9001 contains requirements for the product.

2 The certification of a quality management system is based on a first-party

audit.

3 The DIN EN ISO 9001 indicates industry-sector-specific requirements.

4 The ISO-9001-certificate is valid without any time limitations.

5 The ISO TS 16949 contains requirements for a quality management system

for the automotive sector.

6 “Management decisions“ and “Identify requirements“ are steps of the top-

down-approach during the implementation of a quality management

system.

Picture 5-4: Multiple choice


Name :

St.-ID no. :

Points :

Task 6: Quality management in manufacturing (20 points)

The production process of “milling a flute” is being controlled by the statistical process control

method (SPC). Key factor is the depth of the flute to be milled. The desired depth value is

65.00 mm und for the subsequent assembling process a tolerance of +3.0 mm / -3.0 mm is

acceptable. First step of the SPC is to prove process ability by means of a first running of the

process. The values measured during this first running are shown in table 6-1 below:

Table 6-1: Measured depth values Nr. Time Mean Standard

Deviationi ti x1i x2i x3i x4i x5i si

1 08:00 65,18 64,05 64,72 65,63 66,12 65,14 0,8012 08:15 64 65,65 65,09 63,89 65,22 64,77 0,7823 08:30 65,99 64,57 65,85 65,46 65,33 65,44 ?4 08:45 65,85 66,18 64,86 64,15 65,42 65,29 0,8075 09:00 65,22 64,82 65,03 65,63 65,98 65,34 0,4686 09:15 64,09 65,26 64,45 65,54 65,69 65,01 0,7017 09:30 64,44 65,89 66,01 65,29 65 65,33 0,6488 09:45 65,46 65,1 65,47 66,5 64,62 65,43 0,6919 10:00 64,55 64,02 63,79 64,58 65,26 64,44 0,571

10 10:15 65,28 65,78 64,23 64,59 65,74 65,12 0,693

Values

x i

Advice: As for your calculations please use the formulas and the table provided at the end of this task! As

for your results, three decimal places suffice!

6.1 Process variation (1 point) Please calculate the value 3s missing in table 6-1!

Calculation:

Result 3s : (1 point)


Name :

St.-ID no. :

Points :

6.2 Process capability (8 points)

To be able to make a quantified statement about process capability independent of the process, standardized capability indices pc and pkc are calculated.

Please calculate pc und pkc . Might this process be considered capable? Please, justify your answer!

Calculations:


Name :

St.-ID no. :

Points :

Result pc : (4 points)

Result pkc : (2.5 points)

Process capability including justification:

(1.5 points)

6.3 Control limits (4 points)

Next step of the SPC is to calculate the control limits of the process based upon the measured

values given!

Calculations:


Name :

St.-ID no. :

Points :

Result x

UAL : (1 point)

Result x

LAL : (1 point)

Result sUAL : (1 point)

Result sLAL : (1 point)

6.4 Mean/standard-deviation control chart (1 point)

Please name two standard test procedures for non-random progressions in the mean/standard-

deviation control chart!

1. (0.5 points)

2. (0.5 points)

6.5 Prevention of waste (2 points)

An important issue of quality management in production is prevention of waste. Please name

four starting points for the detection of waste!

1. (0.5 points)

2. (0.5 points)

3. (0.5 points)

4. (0.5 points)


Name :

St.-ID no. :

Points :

6.6 Stocks (1.5 points)

Please name three problems caused by high stocks!

1. (0.5 points)

2. (0.5 points)

3. (0.5 points)

6.7 5S (2.5 points)

In Japanese, the 5S stand for SEIRI, SEITON, SEISO, SEIKETSU und SHITSUKE. What are

the English equivalents for the 5S?

1. (0.5 points)

2. (0.5 points)

3. (0.5 points)

4. (0.5 points)

5. (0.5 points)


Name :

St.-ID no. :

Points :

Formulas:

n an bn cn

2 0,798 3,267 0,000

3 0,886 2,568 0,000

4 0,921 2,266 0,000

5 0,940 2,089 0,000

6 0,952 1,970 0,030

7 0,959 1,882 0,118

8 0,965 1,815 0,185

9 0,969 1,761 0,239

10 0,973 1,679 0,284

( )

scLAL

sbUAL

nxLAL

nxUAL

a

s

n

xxs

ns

ns

x

x

n

n

ii

⋅=

⋅=

⋅−=

⋅+=

=

−

−=∑

=

σ

σ

σ

ˆ576,2

ˆ576,2

ˆ

11

2

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