U3 Flashcards
1
Q
A firm can use many techniques to follow requirements or perform to what has been previously specified. This unit outlines seven elementary quality tools (“Q7”) used to?
A
monitor quality, e.g., on the production floor.
2
Q
The unit also explains seven management tools that are?
A
used by managers to control quality (“M7”).
3
Q
The unit ends with more complex quality techniques, which help
firms ?
A
capture, visualize, and analyze problems.
The term quality technique is rather broad and includes quality tools, management tools, and further techniques.
4
Q
Many of the tools, especially the Q7 and M7 tools, are easy to use by?
A
assembly workers or line managers without in-depth knowledge of quality control or complex computer software.
5
Q
The visualization tools can be implemented by using a standard spreadsheet program and can be?
A
adapted to different types of problems.
6
Q
Many of these techniques have their origin in?
A
the 1960s
when Japanese firms wanted to increase the quality of their products.
7
Q
A lot of companies were successful in finding and eliminating?
A
problems in the production process.
8
Q
tools were kept as simple as possible?
A
Because many of the tools used were developed for workers in production plants.
9
Q
Tools. They are also called “seven tools,” “seven new tools,” “quality control tools,” and “creativity techniques”?
A
-These were used to capture errors,
=find problems,
=assess the impact of errors,
=check error sources,
= visualize connections,
=and confirm the effects of improvements.
10
Q
An error collection list (or data collection sheet) is either a piece of paper or part of a software that is used to?
A
document and display errors.
11
Q
It is helpful to detect causes or patterns of problems. Before it can be used, typical errors should be ?
A
noted and clearly described.
12
Q
The person who documents the error needs be able to do so without?
A
adding more errors.
13
Q
Moreover, it is not very helpful to have a separate open category in which “other” errors are ————. This vague category does not help with future
—————————————-.
A
documented
improvement or prevention
14
Q
If an “other” category is indeed added, it is better to ?
and ?
A
document the type of error to track its frequency
and decide whether it should be added to the typical error list.
15
Q
The error list should also contain a time frame in which the error should be documented, e.g.,?
A
every hour, day, or week.
16
Q
It should ideally contain information on:
A
the process,
component or faulty part,
date, time,
and person who documented the error.
17
Q
Also helpful is a graph that shows?
A
the checked component and the typical errors that usually occur.
18
Q
Overall, error collection lists are very easy to use and provide information about?
A
the problem to help find the cause.
19
Q
table
A
20
Q
The table above shows an example of an error collection list of ?
A
a Silgranit kitchen sink without a picture or graphic.
21
Q
Silgranit is :
A
a durable, scratch-proof material containing a mixture of about four-fifths granite and one-fifth acrylic and ceramic (Blanco, n.d.).
22
Q
The error list contains:
A
information on the product, process, place, and examiner.
23
Q
The effort of using error collection lists is very low, because?
A
errors are simply counted and documented, and the benefit is great.
24
Q
Statistics, especially histograms, can be compiled from ——————–very easily
A
the data
25
Flow chart
A flow chart is a diagram that describes and represents a process or system.
26
Business processes contain:
input,
activity or value-added,
and output.
27
A flow chart is
a graphical representation of these business process and shows how numerous different sub-processes interact with each other to complete the whole process.
28
Flow charts are commonly used in business because?
they are easy to use and very helpful to see the “big picture” of a business process. Some even call it “one of the best techniques of quality control” .
29
Besides providing the big picture, a flow chart can also?
A simple flow chart is laid out the following way.
a lot of detail. Flow charts can be used in quality control and in the planning process.
It contains an input (e.g., a document or someone placing an order of raw material) and always ends with an output (e.g., customer receives meal or a product is manufactured).
30
In between, there are:
-numerous activities that need to be performed, -decisions to be made,
-sub-processes to perform,
-and checks to undertake.
31
The input and output are:
processes displayed in an oval shape,
activities in a rectangle,
and decisions in a diamond.
32
The representation is standardized and explained in DIN 66001
table
33
The graph shows a hypothetical simple process.
It shows that the machine should only be started once it is on.
34
The start button should not be pressed when?
the machine is not turned on,
and therefore a decision loop is included to make sure that the machine is turned on.
35
Pressing the start button before the machine is turned on could harm the machine; thus,?
turning the machine on beforehand is part of quality control.
36
This is a simple example,
yet flow charts are very helpful for quality management, e.g., when new personnel are hired, they can get a good understanding of processes and tasks.
37
To create a flow chart, use the following steps
=Understand and identify all steps in the process. Order the steps chronologically.
= Lay out the steps in the flow chart.
=Review the chart with someone experienced with the process.
=In addition, we can also assign responsibilities for the processes in a flow chart if that is desired or needed.
38
There are many software programs that ------------the representation of flow charts. A quick search in an internet browser provides several ----------------------------------------.
facilitate
free solutions
39
Histogram
A histogram is a type of graph that displays rectangles of different lengths to show how frequently each value in a group of data occurs within different ranges.
40
A histogram is a ?
column diagram and a basic tool for displaying statistics.
It shows the frequencies of quantitative data.
Histograms are used to display continuous numerical data.
41
The goal is to ?
the data are distributed symmetrically or whether they are skewed to the left or right. The graph also shows the maximum and minimum value in the graph (Luthra et al., 2021, p. 41).
represent the distribution of the data and to understand the data properties.
42
After analyzing the histogram, we see whether?
the data are distributed symmetrically
or whether they are skewed to the left or right.
43
The graph also shows the maximum and minimum value in the graph.
graph
44
The data are divided into smaller sections (classes). The frequency of the data is then?
counted in a frequency distribution table or taken from the error collection list.
45
From this table, vertical bars are formed on the x-axis.
The frequency is shown on the y-axis, and the height is proportional to the frequency of occurrence in the data.
46
The histogram in the graph above was constructed with statistical software.
47
It shows the frequencies of 250 average process times (N=250).
The distribution has a mean process time of 162.29 minutes and a standard deviation of 46.57 minutes.
The y-axis on the left shows the frequencies: The higher the bar, the greater the frequency.
The x-axis shows the average duration of process times in designated classes.
48
There are several guidelines to follow when constructing a histogram (Foster, 2017, p. 273):
-The width of the histogram bars must be identical (e.g., 0—4, 5—9, 10—14).
-The classes must be mutually exclusive (e.g., 0—5 and 5—10 are not possible because 5 would be assigned to two histogram bars) and all-inclusive (e.g., 0—4 and 6—11 are not possible, because 5 is not included in the class representation).
-The minimum number of classes in a histogram is calculated with the following formula: \n\n\n\n\n\n\n\n \n \n \n \n\n where n represents number of raw data values and k represents the number of classes.
49
The number of classes can be retrieved by restructuring the formula to the equation:
picture
50
In the example above, 250 average process times were measured. By applying the formula, we receive at least eight classes (as shown in the graph)
picture
51
Generally, the number of classes should be above
--------------. When using fewer than five classes, the form of distribution does not make much ---------------------------------------------.
five
sense or add value
52
The width of the classes is calculated by dividing the range (maximum value – minimum value) by the number of classes:
picture
53
The classes are then built by starting with the minimum value (here usually a slightly lower value is used to?
start the first class) and adding the class width: class 1 [53—88], class 2 [88.1—123.1], class 3 [123.2—158.2], class 4 [158.3—193.3], class 5 [193.4—228.4], class 6 [228.5—263.5], class 7 [263.6—298.6], and class 8 [298.7—233.7].
54
Statistical programs, like SPSS, or spreadsheet software, like Excel, help with the representation of histograms. Because?
Excel or comparable spreadsheet programs are installed on almost every computer and free alternatives exist (e.g., OpenOffice), there are virtually no costs to using histograms for quality control.
55
A Pareto chart (or dual axis graph) is used to?
analyze causes of problems, e.g., in the production process.
56
The Pareto principle is sometimes also called the
-----------------------, which means that ---------- percent of the causes lead to -------- precent of the problems.
20\/80 rule
20
80
57
it is beneficial to sort problems or errors by their occurrence frequency.
Because of this rule,(The Pareto principle)
58
The few causes that lead to the majority of problems should ideally be?
improved or eliminated.
59
picture
60
The dual axis graph above refers to the errors in the production of kitchen sinks previously discussed in this unit. It shows the error types (missing part, color deviation, scratch, dent, and inaccurate drilling) on the x-axis. The y-axis on the left side refers to
61
the number of errors, represented by the blue bars, which are ordered by the number of errors in descending order from left to right. The y-axis on the right side refers to the cumulative percentage of errors, represented by the black line. The red dotted line is drawn for easier understanding of the Pareto chart.
62
It intercepts the y-axis line at 80 percent cumulative percentage. It seems as if most of the errors are due to missing parts and color deviations.
To be more precise, 80 percent of the errors are to the left of the dotted line, and 20 percent of the errors on the right of the dotted line.
Scratches, dents, and inaccurate drilling make up about 20 percent of the errors.
63
After looking at this Pareto chart, the firm should try to improve the processes, specifically to reduce the number of missing parts and to improve the number of kitchen sinks that deviate in color.
64
The Pareto chart is used widely because?
firms can expend little effort and receive a high value in using it.
They can set priorities for improvement and justify the order objectively
65
The graph can either be constructed with --------------------------------------------------, so again, the tool can be easily applied by virtually ----------------------.
statistical software or with Excel
every firm
66
A correlation is a statistical analysis that measures ?
the linear relationship between two variables. The correlation analysis helps explain the strengths and the direction of the relationship.
67
For example,
age and body height correlate positively with one another.
68
A correlation only gives information about the strengths and direction of the relationship between?
the variables and does not draw any conclusions about the causation (cause-and-effect).
69
With a correlation analysis, one cannot predict the influence of one variable on another. One needs a sufficiently large sample of at least ?
30 measurements.
70
Yet, larger samples of at least------------------------------ measurements are preferred.
A scatter plot can provide a ------------------------------ of how the data are distributed and predict the relationship.
50 to 100
first indication
71
picture
72
If we require more than a simple prediction, it is possible to measure ?
the relationship between the two variables. Pearson’s correlation coefficient is used to calculate the linear relationship of two variables, statistically.
73
The Pearson’s correlation coefficient is the covariance of both variables divided by?
the product of their standard deviations.
74
the product of their standard deviations. For a sample, the formula is ?
picture
75
picture
76
The coefficient can take a value between?
—1 and +1. Values around 0 indicate that there is no correlation between the variables.
77
Values between +\/—0.1 and +\/—0.3 indicate a
---------- correlation; values between +\/—0.3 and +\/—0.7 are ------------------ correlations; and high values in -------------- terms (either close to +1 or —1) indicate a strong correlation between the two ----------------.
weak
medium
absolute
variables
78
The correlation can easily be calculated with?
Excel, other common spreadsheet programs, as well as statistical software.
79
Correlation analysis is sometimes used to?
start the error elimination process, even if no cause-and-effect can be found by using this method.
80
Cause-and-effect diagrams are also called Ishikawa diagrams because?
they were developed by the Japanese quality expert Ishikawa.
81
The graph is sometimes referred to as?
the fishbone diagram, because of its shape.
82
The main idea is to?
find solutions to problems and portray these in a structured way.
83
The diagram thus displays suspected or proven causes of a problem and distinguishes between?
main causes and reasons.
84
To construct this type of diagram, :
-we first place the problem on the right side of a piece of paper.
-The second step is to either create categories or use Ishikawaʼs.
equipment, process, people, and raw material.
85
-Originally, Ishikawa used four main causes when applying the cause-and-effect diagram in the context of production:
equipment, process, people, and raw material.
86
Today, the environment and management are often added as?
potential categories.
87
An adequate template of the model is shown in the diagram below.
88
Next, a brainstorming session is?
conducted to identify the root causes of the problem and assign them to the categories.
One needs to assess each cause carefully and plot these in the diagram.
89
After the diagram is completed, it needs to be?
analyzed.
90
If the same cause appears several times, it is easy to see?
how to proceed with quality improvement.
91
In addition, a weight assessment can be used to?
prioritize problem diagnosis, where each person in the team can give points to solutions; the solution with the most points is selected.
92
The diagram is combined with other quality tools to either?
first diagnose the problem or find the causes.
93
There is no special software tool or expert knowledge required to?
construct cause-and-effect diagrams.
94
Quality control charts are among the oldest and most important tools to?
control quality.
95
These graphics display a series of statistical numbers (e.g.,?
upper and lower limits) taken from a sample
96
The goal is to visualize sample parameters, e.g., ?
mean values and data spread, and examine the behavior of a process.
97
With the help of the graph, it is easy to see if the process is under control. If the process is not under control, we can?
react quickly, find the cause, and eliminate the problem.
98
A sample may be taken, for example,
on a regular basis in the production process.
The x-axis represents the time when the sample is taken (e.g., 1, 2, 3, and 4).
The time frame depends on how often variations take place, e.g., hourly, daily, or weekly. The values from the sample are then plotted on the y-axis of the graph. If the deviation from the specified limits is too big, it is possible to correct or regulate the process.
99
picture
100
The center line (CL) is determined by?
previous data, e.g., a run in the test phase.
101
The upper (UCL) and lower control limits (LCL) are:
determined statistically by the accepted error rate and required specifications.
102
When a kitchen sink is produced and its size is beyond the upper specification limit, as seen at sample time 8 in the graph, it is considered ?
scrap and needs to be reworked or discarded. UCL and LCL are often the
103
mean value +\/—3 sigma (σ standard deviations) around the target mean.
104
Values below LCL and above UCL are typically seen as ---------------, which means that something is out ---------------------.
problematic
of control.
105
The upper (UWL) and lower warning limits (LWL) are often set to?
the mean value +\/—2 sigma (σ standard deviations) around the target mean.
106
The upper specification limit and the lower specification limit usually lie +\/—6 sigma (σ standard deviations) around?
the target mean and therefore represent nearly zero defects.
107
Quality control charts need to be?
examined after every entry, otherwise it is impossible to react to deviations quickly.
108
The main objective of using process control charts is to ?
“ensure the quality of the process,” especially when there is variation in the process, and thus tolerance limits are helpful.
109
If the warning line or control limit is exceeded in?
a sample or if an upward or downward trend is recognized, it is advised to sample more regularly to check whether the action to eliminate the problem was successful.
110
Ideally, the quality control chart also includes:
flow charts with decision rules, so that common problems can be eliminated quickly
111
Although quality control charts are helpful to spot problems, they are?
a reactive tool
112
The problems can only be eliminated after?
limits have been breached and the problems have already occurred.
113
Only if trends are visible, can one foresee future problems and eliminate them before?
they occur.
114
Managers have a variety of tools they can use to improve?
processes and products.
115
This section explains several management tools that help?
support a firm to solve problems.
116
first introduced these primarily visual tools (also called M7) in Japan in 1978 was?
The Japanese Union of Scientists and Engineers (JUSE).
117
These tools are also called?
the “new seven tools for quality control” or “new seven”.
118
They are usually applied during group work in the planning and development phase of a project when?
numerical data are not yet available.
119
In addition, the tools support the quality control tools that were discussed in ?
the previous section.
120
Brainstorming
The process of finding the (best) solution to a problem by collecting spontaneous ideas is commonly known as brainstorming.
121
When teams use the brainstorming technique to develop ideas, these are initially rather?
unstructured, and there is need to put them in order.
122
An affinity diagram helps :
structure ideas, see relationships, and develop new approaches toward solutions.
123
table
124
According to Foster and Benes and Groh, there are a series of steps to create an affinity diagram in a team environment after material has been collected in a brainstorming session:
1-Identify and spell out the problem in a short and clear statement that everyone in the group understands.
2-Give group members about ten minutes to write issues related to the problem on note cards. Make sure only one idea is written on each card.
3-Lay out note cards on a flat surface and let team members quickly group the cards into similar themes or clusters silently (without discussion).
Continue to move cards silently into piles until consensus is reached.
4-Discuss headings of the sub-issues thoroughly and create header cards.
5-These headers then create options for the problem solution.
6-Draw an affinity diagram of the solution and order the solutions according to their importance using a color-coded sticker, e.g., red (extremely important), yellow (important), and green (less important).
7-Provide each team member with a copy of the diagram, e.g., take a picture of the original and attach it to the protocol.
An affinity diagram can be constructed in a team session and improve team quality. No extra software is necessary for its development. It is a very quick and easy way to find ideas in a communicative way.
125
The interrelationship diagraph helps?
identify solutions to problems.
126
Like the affinity diagram, it is another graphical representation to :
combine facts,
relationships,
and arguments that cannot be displayed with numerical numbers.
127
In particular, the interrelationship diagraph allows the connection of?
dependencies and their weighting as driving forces or outcomes.
128
To construct an interrelationship diagraph, follow these steps (Benes & Groh, 2017, p. 281; Foster, 1996, 2017, p. 286):
1-Phrase the problem in a clear sentence and place it in the middle of a bulletin board. The prior construction of an affinity diagram helps to identify all the issues that relate to the problem. Put these issues on sticky notes or note cards and add these to the bulletin board.
2-Examine the issues and create the graph. Use one note card at a time and check if there is a relationship between issues on the bulletin board, e.g., ask “what other issues on this diagraph are caused or influenced by this issues?” (Foster, 2017, p. 286). Draw arrows for the identified causes and effects. Never use double-pointed arrows. Continue working until all issues are addressed. It is helpful to first draw a cause-and-effect (fishbone) diagram to be clear on the relationships (Herrmann & Fritz, 2018, p. 163).
3-Quantify the issues by counting how many arrows point toward the note. The card with the most arrows pointed toward it is a “key factor” (Foster, 2017, p. 286). Evaluate the key factors. Note that performance indicators are those with many incoming paths, and root causes are those with many outgoing paths (Foster, 2017, p. 286).
129
picture
The interrelationship graph shows an example of a firm that wants to introduce new interactive whiteboards in their meeting rooms.
130
In the past, hardware updates were frequent and poorly communicated. Employees were therefore?
skeptical and feared the change from traditional whiteboards to the new interactive board.
131
knowledge. The interrelationship diagraph shows that the main performance indicator is?
the successful introduction of new whiteboards with five incoming arrows.
132
The root cause with four outgoing arrows is?
the provision of good training material.
133
Overall, the interrelationship diagraph is a useful tool that provides:
a clear, structured visualization of a problem.
134
The main difficulty in applying the tool is to precisely identify all. Therefore?
careful preparation is needed, e.g., the use of an affinity diagram or a cause-and-effect (fishbone) analysis.
135
The effort of constructing such a graph is?
low, and no software is necessary.
136
A tree diagram is “useful to?
identify the steps needed to address the given problem”.
It can display relationships and hierarchies using different layers; the complexity of the graph increases with each additional layer.
137
The name of the diagram derives from?
its typical branches.
138
A tree diagram is used to investigate a ---------------------------------------in several consecutive steps by looking into causes and possible solutions. It can be used as part of----------------------------------------- to develop measures and means to achieve a goal.
problem systematically
process management
139
Therefore, it is also known as?
a means-ends diagram.
140
Like the relationship diagraph, it also is built by?
writing and pinning note cards on a board.
141
According to Benes and Groh (2017, p. 284), four steps should be undertaken to construct the tree diagram:
==The problem is formulated, written on a note card, and pinned on a board.
==The first layer with causes of the problem is constructed. Typically´, this first level contains three to five branches.
==In the next layers, the causes can be explained in more detail. To get to the next level of detail, ask the following question: “What are the steps required to resolve or achieve this major objective or goal?”.
==Each sub-item is then investigated further. The previous question is asked again until the process is exhausted.
142
table
143
table
The graph shows a tree diagram for a firm that wants to introduce an interactive whiteboard successfully.
144
(The example has been used previously, but the graphs are not ---------------. The topic just serves as an illustrative example.)
linked
145
The problem is phrased on the left.
Causes are identified and further details are collected.
The means to an end are presented on the right-hand side of the diagram.
146
The tree diagram is also rather?
simple to use,
and no further software or skills are required.
147
Sometimes problems are too complex and require people to think in more than one dimension. The matrix diagram is a systematic representation of?
relationships and structures information that contain two or more dimensions in one graph.
148
The matrix diagram is used to present the relationship between ?
two or more groups of information.
149
Although the goal of using matrix diagrams is to find?
solutions to problems, it is also possible to link tasks and responsibilities.
150
The following steps need to be followed to construct a matrix diagram:
==The number of dimensions is chosen. The type of matrix is selected.
==The dimensions either come from a brainstorming session or are taken from an affinity diagram (Benes & Groh, 2017, p. 283).
== The matrix is filled with appropriate symbols. These show the relationship and responsibilities and can even assign actions (Benes & Groh, 2017, p. 283).
151
There are various types of matrix forms because?
each problem is unique.
152
Very common is the use of a two-dimensional
------------------, which is typically used when applying the house of ----------------------, e.g., to assess design demands and customer demands. T-matrix, which is
L-matrix
quality
a combination of two L-matrices.
153
Three dimensions are displayed in a?
T-matrix.
154
T-matrix, which is?
a combination of two L-matrices.
155
There could be two dimensions of a problem (e.g., ?
error feature,
corrective action,
and a third dimension like problem cause).
156
The Y-matrix is even more?
complex and can assess four dimensions.
157
The various matrix forms are displayed in the figure below. Although they are not shown here, three-dimensional graphs may also be used.
picture
158
Relationships and responsibilities are represented with symbols. In the example of the L-matrix, there is a weak relationship between?
dimension A3 and B1, a medium relationship between A2 and B2 and A3 and B3, and a strong relationship between A1 and B4.
159
The T-matrix displays relationships between
------------------------ on the top and ------------------at the bottom. Dimension ------- could thus represent functional teams in a company or company departments like ---------------------------------------------------------------------------------------
dimensions
responsibilities
C
research and development,
sales,
production,
and human resources.
160
Overall, it is not difficult to construct a matrix diagram. There is some effort and preparation required, but the diagram can be displayed using ?
a simple spreadsheet program.
161
Matrix diagrams are helpful to display complex relationships between several dimensions. The more dimensions used, the more?
complex and confusing they become.
162
Portfolio
The term originates from the Italian word portafoglio for briefcase (Herrmann & Fritz, 2018).
163
Portfolios provide guidelines for ----------------. They are used to -----------------------------------------objects. A portfolio analysis is also called a --------------------------.
strategists
analyze, compare, and evaluate
matrix analysis
164
After the evaluation of three dimensions, they are displayed in a coordinate system to evaluate ?
potential for development or develop strategies for growth.
165
The portfolio analysis can be used to?
compare products of different companies or different strategic business units within a company.
166
The analysis starts with the current situation and then?
new targets are identified.
167
A well-known portfolio is the Boston-Consulting-Matrix, which displays?
market growth and relative market share of the firm’s strategic business units.
168
A spreadsheet program like ------------------can be used to create a portfolio.
Excel
169
The following steps need to be followed for a portfolio analysis (Benes & Groh, 2017, p. 282):
-- Determine the objects to be compared.
--Choose two attributes that are used for evaluation. Place these on the x- and y-axes.
--Determine the values for the chosen objects.
170
An example of a portfolio analysis in quality management is displayed in?
the graph.
171
A firm might have identified------------------- in a team session. The firm then categorizes these according to -----------------------------. One dimension could be importance (high, low) in terms of estimated decrease in ----------------------------------------. The other dimension could be the urgency of the problem (high, low). The third dimension, which is shown by the size of the------------in the portfolio, portrays how much effort (in terms of estimated working hours) it will take to solve the problem.
five problems
priorities
customer dissatisfaction
bubbles
172
From the portfolio, it is evident that problem three is?
high in urgency and high in importance.
173
Therefore, the firm needs to tackle the problem and should try to?
reduce the urgency and its importance to move the problem into the lower left quadrant.
174
As shown by the bubble size, resolving problem three requires:
the most working hours, but should still be resolved first.
175
picture
176
it is a very useful tool to visualize large amounts of three-dimensional data?
Because no special software is required to build a portfolio
and because the effort in constructing it is low,
177
When a firm undertakes projects, a number of problems usually occur. A problem decision plan allows us to?
collect potential problems and think of potential solutions to these problems ahead of time in the planning phase.
178
A problem decision plan is thus?
a graphical representation of a systematic analysis of potential problems and possible solutions in a project.
179
The goal is to/?
identify time-critical processes
and prevent critical processes from causing problems.
180
It has a similar function to --------------------------------------------------, which is discussed in this unit.
the failure mode and effects analysis (FMEA)
181
picture
182
picture
As shown in the graph, once the goal and the process steps are specified, the project team reflects, identifies, and documents potential problems or disturbances. Countermeasures are then developed to address these problems. Finally, the team documents the countermeasures it implemented.
183
The effort of preparing a problem decision plan is high (Herrmann & Fritz, 2018, p. 170), because?
little help.
the project team needs to think of potential problems and solutions in future contexts.
184
Whether or not the plan is helpful depends on?
how diligent the team is in the preparation phase and whether they can really predict all potential problems.
185
When unforeseen problems arise, the tool is of--------------------
little help.
186
The graph itself can be easily constructed using standard ?
spreadsheet or word-processing software.
187
When analyzing complex problems, it might be helpful to?
split these into several problem decision plans to simplify the analysis and facilitate the evaluation.
188
Activity network diagrams are also called ?
program evaluation and review technique (PERT)
or critical path diagrams.
189
The basis for construction is a?
tree diagram and a table that lists all activities in the tree diagram.
190
The figure below shows a tree diagram and an activity on node (AON) diagram.
pic.
191
table
192
table
193
-The following steps need to be undertaken to construct an activity network diagram:
1-Construct a tree diagram and identify the inputs.
2-Determine how long the tasks will take (activity time in weeks).
3-Determine the relationships between the tasks and identify which items need to be completed before the task can be started.
4-Draw an activity on node (AON) network diagram.
5-Calculate the early start and finish times and complete these in the AON network diagram (these are calculated by starting with 0 on the left and adding the times to the right. Here, the time for the earliest end time is calculated for the project.)
6-Calculate the latest start and finish times and complete these in the AON network diagram. These are calculated going backwards from right to left. Here, the latest possible start- and end times are calculated without having to shift the time schedule of the project. The earliest end date (EED) is the earliest start date (ESD) plus the process duration
7-Compute available slack or reserve time:
pic.
194
pic.
195
The total reserve time is the time span that a process can be?
moved, in respect to its earliest start, without influencing the project end.
196
pic
197
The unused reserve time is the time that the process can be moved forward without delaying the next process:
198
8-Determine the critical path. This path has zero slack or reserve time and is thus the longest path in the process. The critical path is highlighted in red in the activity network diagram below.image
199
pic
200
An activity network diagram can quickly become complex. ?
Therefore, the effort can be reduced by using project management software. It is a very useful quality tool
201
because time critical dependencies can be?
determined in advance. This knowledge is helpful in reducing project delays early on (Herrmann & Fritz, 2018, p. 173).
202
The previous sections addressed elementary tools (Q7) and quality management tools (M7). This section deals with further quality techniques, which ?
they are much more complex and require deep knowledge (Herrmann & Fritz, 2018, p. 178) or quality teams from several departments to provide insight and help with quality improvement.
improve the quality or help solve problems.
203
Many of these techniques cannot be applied as easily as the Q7 or M7 anymore, because ?
they are much more complex and require deep knowledge or quality teams from several departments to provide insight and help with quality improvement.
204
The origin of failure mode and effects analysis (FMEA) dates to?
the middle of the twentieth century.
205
Some authors report that FMEA was originally developed in?
the 1940s, whereas others date its origin to the 1960s, when the aerospace industry used it in six sigma.
206
The Ford Motor Company applied FMEA to analyze its -----------------------------, and continues to use it to
------------------------------------------- . Today, this analysis is established in many industries, and several ----------------------norms (e.g., DIN ISO\/TS 16949) demand its usage.
engineering design
analyze software applications
DIN ISO
207
Failure mode and effect analysis “identif[ies] all the possible causes of failure of a product from?
the very first stage, that is, the design or manufacturing process itself”.
208
Effects are the result of the identified failures. The result of the analysis is ?
a compilation of the failures, their seriousness, and the frequency of occurrence.
209
FMEA can be used in the planning and design phase of a product or during the production planning process, e.g.?
Often, a distinction is made between System FMEA, which looks at errors in the overall system; Design FMEA, which looks at construction errors at the design process; and Process FMEA, which identifies errors in the production process
, when material is selected.
210
In addition, FMEA can be used to increase?
product quality as a tool for continuous improvement at any time during the lifespan of a process .
211
Other authors report FMEA to be used for a systematic analysis of?
five system components .
212
five system components :
-Concept, which analyzes the design conception of a system.
-Process, which analyzes the manufacturing process.
-Design, which analyzes the mass production products before the production starts.
-Service, which analyzes processes before they are first introduced to the customer.
-Equipment, which analyzes equipment used before the purchase.
213
The goal of FMEA is to reduce the occurrence of ?
errors and associated risk by introducing mechanisms for risk reduction.
214
errors and associated risk by introducing mechanisms for risk reduction. Because of?
its systematic approach, it is ideal as part of an ISO 9001 certification.
215
Four steps are necessary to conduct a FMEA (Benes & Groh, 2017, p. 226):
==System analysis. Processes are picked for evaluation, teams are formed, responsibilities are assigned, and dates are set. The task is structured and distributed among team members.
==Error analysis. Potential errors, causes, and effects are identified and measures for improvement are developed. The current situation is evaluated based on severity, occurrence, and possibility of detection.
==Risk evaluation. All weak areas are identified and mechanisms for risk reduction are determined.
==Optimization. The mechanisms are executed, and due date and effectiveness are monitored. The current situation is reevaluated.
216
The most important factor for the evaluation is?
the risk preference number (RPN), which indicates how likely an error and its effects will occur.
217
The score is calculated the following way:
picture
218
Severity refers to?
how important the error is for the customer.
219
If it is unlikely that the error has effects on the customer, the score is -------------. If the error has severe consequences for the customer, the highest score of ------ is given.
1
10
220
Probability of occurrence refers to?
For example, errors that hardly ever or never occurr get a score of 1. When the error is almost certain, the score is 10
how often the error occurs.
221
Here, contrary to the other two dimensions, low values represent ?
a low probability of occurrence.
222
Probability of detection refers to the probability that the error is ?
recognized before the product is delivered.
223
Here values between 1 (high) and 10 (low) are assigned. One could refer to ?
probabilities greater than 99.99 percent and 10 to probabilities below 90 percent with respective values in between.
224
Multiplying the three values will give the risk preference number (RPN), which can have ?
values between 1 and 1000. Low scores represent little risk and high scores correspond to high risks.
225
Scores starting around ?
100 or 150 require action and optimization.
226
picture
227
Normally, it is not advisable to start action based purely on?
the risk preference numbers.
228
As in the table and the mentioned formula, the RPN is a product of-----------------------. Therefore, a high score above, e.g., 100, can be reached by
---------------------------------.
three numbers
using different
229
combinations of numbers for S, O, and D. The graph indicates that the highest risk preference number is for failure mode “color deviations”;
230
if the decision was purely based on ?
numbers, corrective actions on color deviations should be taken.
231
Yet, for the customer, the most serious factor is ?
the delivery of the wrong kitchen sink because it then cannot be assembled on the same day.
232
Thus, the table shows that all failure modes need to be carefully analyzed, even if ?
the risk preference number is low in comparison.
233
It is advisable to determine final decisions on?
appropriate actions based on common sense, or as a result of team discussion, than purely on numbers.
234
Quality function deployment (QFD) is a method for ?
planning quality and helps to implement customer design requirements , which can be applied in all service organizations or firms that work in the manufacturing industry.
235
Failing to fulfill customer requirements is as ?
problematic as overfulfilling, because customers are not prepared to pay for the extras.
236
Firms are thus interested in?
fulfilling customer requirements on the desired level.
237
QFD “is a method for systematic and comprehensive quality planning based on ?
customer requirements, their importance, and their relationship to the characteristics”.
238
This quality planning involves:
sharing the responsibility with all departments of the firm.
239
image
240
The main idea behind QFD is?
to translate the requirements customers have (voice of the customers [VOC]) into the technical requirements needed for production.
241
The firm goes through a -----------------------------------. The first is product definition, where customer requirements are specified into product
--------------------. In the second step, product development, the functional product attributes are --------------------, and the product is developed.
series of four steps
specifications
specified
242
The third step is ?
process development, where the process and process flow for assembly and services are designed. Lastly, process control is specified.
243
Indeed, the house of quality is the central tool for?
QFD
244
The house of quality is a ?
“planning matrix” and translates the customer voice into product requirements.
245
It is particularly helpful for QFD because?
it uses a systematic approach and displays the results nicely.
246
Often, the tool takes the representation of a
------------. The left wall has the customer requirements, the roof the ---------------------------------; the right wall is a competitive assessment of customer requirements; and the bottom is a ---------------------------assessment of the technical requirements.
house
technical requirements
competitive
247
pic
248
The house of quality, as shown in a simplified form in the figure, corresponds to?
a matrix that answers several questions :
WHAT? What do customers demand? These characteristics or requirements are categorized and weighted based on their importance.
HOW? How are the demands fulfilled? The quality characteristics of the product and technical specifications need to be derived here from the demands.
HOW MUCH? The target objectives are set here and an assignment of target characteristic values to the quality characteristics takes place. Furthermore, the degrees of difficulty in the realization of the quality characteristics is estimated.
WHY? How good do competitive products fulfill the WHAT? Here, an assessment of products from competitors is conducted from the customer perspective. In addition, the technical characteristics of the planned products are compared to competitor products.
249
A quality planning team comprised of experts from all areas of the firm (e.g.,?
research and development,
marketing and sales,
quality management,
production,
customer service,
and general management) is formed to use the firm’s know-how.
250
The input are the compiled customer requirements, e.g.,?
from a market research study. The questions are then answered and quantified.
251
At the end, target values and other key figures are derived to?
make further strategic decisions.
252
Using the house of quality is a challenge for firms:
first because it takes time until results are realized, and second because the application is very complex.
253
Yet, it is a comprehensive method that, if applied accurately, can bring?
forward potential for improvement.
254
Design of experiments (DOE) is a?
method for finding solutions by conducting the smallest possible number of experiments.
255
Foster compares the method to -----------------------.
baking a cake
When someone is baking a cake, there are lots of different ingredients to choose from. The amount of flour, number of eggs, and tablespoons of sugar, for example, can vary. If there is no recipe available, how does one go about experimenting with the recipe?
256
Instead of using trial and error, a product engineer can find?
the best solution by designing and quantifying the experiment.
257
Japanese engineer and expert in quality improvement, Genichi Taguchi invented DOE, which is also called?
the Taguchi method or experiment design
258
His method is helpful to reduce ?
failures and increase customer satisfaction.
259
The main aim is to?
reduce costs that a product generates beyond the production process.
260
The method systematically examines and documents the effect of inputs on?
responses using statistical methods.
261
The method systematically examines and documents the effect of inputs on responses using statistical methods. Thus, ?
one needs to find the relevant parameters that influence the process.
262
This is done by defining the values of desired output variables and plugging the needed input variables into ?
the statistical function to obtain the desired results.
263
ANOVA
An analysis of variance is an extension of the t-test and is used for hypothesis testing. It tests the mean values of more than two groups.
264
Taguchi proposed using quantitative methods, like?
ANOVA and response charts,
and carefully set the number of responses in an experimental design.
265
Orthogonal arrays are typically used when?
setting up these experiments.
266
Excel can help with the calculations, particularly to?
engineers finding optimal parameters.
267
Robust processes
A process is robust if it is designed “defect-free and insensitive to random variation”
268
To find optimal parameters, Taguchi’s method uses?
the principle of robust processes.
269
A robust process is insensitive to?
disturbance variables.
270
To create a robust process, there are three design stages:
1-Concept design is the phase when the product and processes are planned. Technical and scientific knowledge is used to develop a prototype or a concept, e.g., the layout of a service store or the order of processes. In the cake example, the steps of the process are identified here.
2-In parameter design, the development team searches for the optimal parameters, e.g., in terms of process speed or material, to reach the desired output parameters. When referring to cake baking, the parameters refer to the ingredients and their respective amounts (Foster, 2017, p. 382).
3-In tolerance design, tolerance limits are specified and the balance between manufacturing cost and loss are determined (Luthra et al., 2021, p. 10), e.g., process variation is limited because higher quality material is used (Foster, 2017, p. 381).
271
The Taguchi method is based on?
the following quality definition: “Quality is inversely proportional to the loss caused by a product after its delivery”.
272
The Taguchi method is based on the following quality definition: “Quality is inversely proportional to the loss caused by a product after its delivery”. Thus, according to the method, there is?
an ideal quality, so that the product or service performs as intended.
273
This reference point is also labeled?
“target quality”.
274
In an older understanding of tolerance levels, loss in the form of scrap occurs when?
the tolerance levels (upper and lower specification levels) are exceeded.
275
According to Taguchi’s newer understanding, if?
the product does not perform as intended, there is a loss to the firm that produces the good, as well as loss to society overall.
276
Genichi Taguchi thus defined tolerance zones because?
every deviation from the target value leads to loss in some way e.g., because the product is less useful to the customer.
277
Therefore, the goal of process and product development is to?
minimize the tolerance.
278
When the quality characteristic is close to?
the target value, there is little loss.
279
The further the quality characteristic is from the target value, the more?
loss occurs.
280
image
281
We can illustrate the quadratic loss function with bananas.
Most people like bananas when they are bright yellow. This might happen, for example, on day five of the ripening process, the target value. When they are still green at day one, people don’t like to eat them. Below the LSL (e.g., day three), eating them is considered a loss because they don’t taste good. According to Taguchi, eating them slightly green is also a loss, because customer satisfaction is not at the fullest level. The same is true for the USL (e.g., day seven) when they are turning brown and are too sweet and too soft for most people.
282
The quadratic loss function (QLF) computes?
the overall losses to society in two steps.
283
In step 1,
a constant,
K, needs to be calculated with the following equation,
in which C represents the unit repair cost and T the allowed tolerance interval of the parameter:
image
284
In step 2,
L, the economic penalty of the customer that has occurred because of the deviation of product quality is calculated.
V2 represents the mean squared deviation from the target value.
285
K is ?
the constant that was calculated in step 1.
286
pic
287
Assume that the kitchen sink manufacturer has a target tolerance level of 5 mm with a deviation of?
+\/—0.5 mm.
288
The cost to repair the sink with greater deviation is $30. The mean squared deviation from the target is ?
image
289
A deviation from the target standard thus costs?
the firm $4.80 per unit.
290
If the firm knows of defects from other problems, it can now compare and set priorities on?
which problems to tackle.
291
Overall, the quality loss function calculates the exact monetary loss of a deviation from?
a target value.
292
The firm should not take the value of the loss literally, because?
the calculated value is an imaginary loss for society overall.
293
The term poka-yoke is?
a Japanese method to prevent mistakes. It was developed by Shigeo Shingo in the mid-1980s.
294
Shingo, who?
worked at Toyota Production, aimed to achieve zero defects.
295
Poka means ?'
“stupid mistake,” and yoke means the “avoidance” of these mistakes.
296
In sum, the goal is to prevent or correct errors before?
they occur and to develop products or production steps in a way so that avoidable mistakes cannot occur. The concept is also called “fail-safeing”.
297
A good example of the implementation of poka-yoke is?
the changed process order at an automated teller machine (ATM) when customers withdraw money.
298
Because the money is a customer’s primary motivation, many customers forget to take their card with them once they receive the cash?
Thus, banks changed the process steps so that customers must remove their card before they receive the cash.
299
As a consequence, customers no longer tend to leave?
leave the cards in the ATM.
300
Alternatively, the ATM might beep so that ?
customers remember their card.
301
Further examples of this method include:
an automatic toilet flush in public restrooms and attached tank lids on a car that cannot be forgotten at a gas station.
302
Poka-yoke is?
simple technical tool that is error-source oriented.
303
To use poka-yoke, the firm needs to?
identify potential errors, e.g., with the help of a quality technique like FMEA
304
Afterward, a cause-and-effect diagram can determine?
the cause of the error.
305
If the cause of the error is known, the team needs to check?
First, it must be a human error that can be reduced or avoided, and second, it must be true that very thorough check can reduce or avoid the error to 100 percent. If these two criteria are not available, another method for failure elimination is needed
whether the error is capable of being avoided using poka-yoke.
306
The criteria for this are twofold:
-First, it must be a human error that can be reduced or avoided,
-and second, it must be true that very thorough check can reduce or avoid the error to 100 percent.
307
If these two criteria are not available,?
another method for failure elimination is needed.
308
Poka-yoke is an easy method to achieve-------------------------------------------------. It can also save the firm a lot of money if cheap error ---------------------solutions are found.
high impact with little effort
prevention
309
The elementary quality tools (Q7) can help to?
plan processes, collect the necessary data to find errors in these processes and analyze these processes.
310
The tools are easy to?
implement,
and no special software or advanced knowledge is necessary.
311
The seven management tools (M7) are mainly used to ?
control processes and help to find problems to solutions.
312
These tools are often used as part of?
a group session to visualize problems and help address them by finding possible solutions.
313
Further quality techniques like FMEA, QFD, house of quality, DOE, and poka-yoke are ?
more complex tools that analyze in much more depth.
314
These are predominantly used?
for quality improvement and problem-solving.
315
Failure mode and effect analysis (FMEA) :
shows the frequencies of errors
and identifies possible failure causes and their effects.
316
Quality function deployment (QFD) is ?
a method for planning quality and helps to implement customer design requirements.
317
The idea is to ?
listen to the voice of the customer and adopt their requirements.
318
The house of quality is the preferred tool for ?
applying QFD.
319
Design of experiments (DEO) is a method for?
Poka-yoke is a method to prevent mistakes and is error-source oriented. Once the error cause is known, the team tries to find a solution to make the process fail-safe.
finding solutions by conducting the smallest possible number of experiments.
320
Genichi Taguchi invented the------------------ and used the quality loss function to show that -------------------------------- in society overall.
method
failure also leads to losses
