Mechanical engineering and issues on teaching mechanical engineering design in Turkey

Abstract

Students with relatively low affinity and/or weak ability for science and mathematics have been presently acknowledged into Mechanical Engineering (ME) departments around the world. This has resulted in apparent lowering of fully competent graduate engineers, due to insufficient comprehension and its concomitant cognitive issues. Now, the complexity and the demand of ME education have been extremely unbalanced with recruited students. This conflict between the education process and less knowledgeable students has been adequately acknowledged, but remedies for this global issue are not yet available. This is no longer sustainable. The paper gives insight into (individual and combined) plausible reasons for fewer fully competent graduate engineers, taking the specific case study in Turkey. It proposes a generic approach, which can be extended to courses of any university/degree subject. Findings on student learning are provided using a hierarchical decomposition. A proposed remedy for this issue has been thoroughly evaluated, and accountability measures, qualitative data and a survey has been conducted for the ME design course taught in Turkey. The findings indicate that the new recruits are not fully to blame for the conflict, because there have also been other reasons for the issues within teaching. It identified multiple instances of the reasons such as unnecessary complexity of textbooks, unsolved contradictions even between the technical component design standards and etc. If these are considered by educators, this will help to reduce the perceived degree of teaching difficulty, and have a positive effect on the quality of graduates. It may even assist in attracting higher ability students into ME.

Full text

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Mechanical engineering and issues on teaching mechanical engineering design in Turkey
Necdet Geren, Cagrı Uzay, Melih Bayramoglu
University of Çukurova, Faculty of Engineering and Architecture, Mechanical Engineering
Department, 01330 Balcalı-Adana, Turkey
This is a preprint of an article whose final and
definitive form has been published in the
Int J Technol Des Educ (2018) 28:843–866
"The final publication is available at link.springer.com”.
It is
available online at:
https://link.springer.com/article/10.1007/s10798-017-9409-0
To cite this article:
Geren N., Uzay C. and Bayramoglu M., “Mechanical engineering and
issues on teaching mechanical engineering design in Turkey”, Int J
Technol Des Educ (2018) Vol 28:843-866,
https://doi.org/10.1007/s10798-017-9409-0
Int J Technol Des Educ (2018) 28:843–866
https://doi.org/10.1007/s10798-017-9409-0
DOI 10.1007/s10798-017-9409-0

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Mechanical engineering and issues on teaching mechanical engineering design in Turkey
Necdet Geren* Çağrı Uzay Melih Bayramoğlu
Mechanical Engineering Department, Çukurova University, Adana, Turkey
*e-mail:gerendr@cu.edu.tr Tel: 90 322 338 6084/2726 Fax: 90 322 338 6126
Abstract
Students with relatively low affinity and/or weak ability for science and mathematics (Sci&Maths) have been
presently acknowledged into Mechanical Engineering (ME) departments around the world. This has resulted in
apparent lowering of fully competent graduate engineers, due to insufficient comprehension and its concomitant
cognitive issues. Now, the complexity and the demand of ME education have been extremely unbalanced with
recruited students. This conflict between the education process and less knowledgeable students has been
adequately acknowledged, but remedies for this global issue are not yet available. This is no longer sustainable.
The paper gives insight into (individual and combined) plausible reasons for fewer fully competent graduate
engineers, taking the specific case study in Turkey. It proposes a generic approach, which can be extended to
courses of any university/degree subject. Findings on student learning are provided using a hierarchical
decomposition. A proposed remedy for this issue has been thoroughly evaluated, and accountability measures,
qualitative data and a survey has been conducted for the ME design course taught in Turkey. The findings indicate
that the new recruits are not fully to blame for the conflict, because there have also been other reasons for the
issues within teaching. It identified multiple instances of the reasons such as unnecessary complexity of textbooks,
unsolved contradictions even between the technical component design standards and etc. If these are considered
by educators, this will help to reduce the perceived degree of teaching difficulty, and have a positive effect on the
quality of graduates. It may even assist in attracting higher ability students into ME.
Keywords Mechanical engineering education; Quality of graduates; Attracting young people; Student problems;
Engineering complexity.
Introduction
Authorities such as the European Commission in EU states, the national science board in the USA, the ministry of
education in China have been studying young people’s general attitudes towards science and technology for several
years. Reports of educational authorities and multiple research studies in the literature indicate a growing decline
of pupils’ interest in science, technology, engineering and mathematics (STEM) subjects in industrialized countries
including Japanese students in the far east (Eurobarometer 2008; The IET 2008; OECD 2014) and (Salas-Morera
et al. 2013; Rohaan et al. 2010). It is stated that students in industrially developed countries including Japanese
students generally undervalue the STEM subjects and careers more than any other young people (The IET 2008).
On the contrary, recent studies stated that generally students in developing countries articulate a much more
positive view towards science and technology than the students in wealthier countries (The IET 2008). According
to the latest PISA (2012), Shanghai-China has the highest scores in science and mathematics with a mean score of
613 points (119 points above the OECD average), or the equivalent of nearly 3 years of schooling (OECD 2014).
It is also stated that the rate of improvement in the mathematics performance of the average student observed in
the 2009 to 2012 period was higher than that observed in the 2003 to 2006 period. Countries like Brazil, Mexico,
Tunisia and Turkey achieved major improvements compared to the previously low levels of performance (OECD
2014), which supports the above.
A great deal of work has also been carried out in Europe too. A significant study (produced by the Institution
of Engineering and Technology (IET)) reports a global consensus on the decline for more than a decade of the
enrolment for STEM studies and/or careers (The IET 2008). The latest Eurobarometer survey conducted on 25,000
young people (aged between 15 and 25) across the 27 EU Member States revealed that in a majority of the EU
countries, at least half of the respondents said that they would definitely not consider studying engineering. This
ratio is even higher in some EU countries. Approximately six out of 10 young people in Spain, Malta, Greece,
Slovakia, the Czech Republic, France and the UK, stated that they would definitely not study engineering
(Eurobarometer 2008).
A report published by IET in the UK identified five barriers or ‘switch-off’ factors which caused students to
lose interest in STEM subjects (The IET 2008). The five factors identified by pupils aged between 11 and 15
thinking about their future careers noted; teaching, perceived degree of difficulty, the transition from primary to
secondary school, gender, and perceptions about careers and future opportunities.
Even though interests of students to STEM subjects and careers are higher in developing countries than
industrialised countries, the perceived degree of difficulty in both contexts is the same, and this is likely to
continue.

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Li et al. (2008) analysed the possible reasons for the quantitative decline in engineering graduates. Cognitive
issues related to development of engineering knowledge and technical skills cause the decline in enrolments.
Increase in a number of drop outs of engineering degree programmes were also stated as responsible for the decline.
There is a consensus that many engineering students feel that STEM related careers (The IET 2008) and
engineering subjects are too demanding (Felder and Brent 2005; Li et al. 2008). Student attrition is another research
topic in the field of higher education concerned internationally (Letseka and Cosser 2010; Caroni 2011; Ahmed et
al. 2015). Student attrition rates in engineering degrees have risen to 50% in Germany (Wolffram et al. 2009) and
Austria (Günther and Koeszegi 2012), over 20% in the UK (MacGillivray 2009), 40% and 48% in Australia for
females and males respectively (MacGillivray 2009), and 20% in Ireland (Morgan et al. 2001).
The qualitative research carried out by Seymour and Hewitt (1997) has revealed that teaching approaches
undermined students’ confidence and progress so much so that many students quit their degree programmes.
Lesser interest in mathematics and science (Besterfield-Sacre et al. 1997; French et al. 2005), higher workloads
than expected and high demand or pressure within the courses, the teaching approach, useless tutorials,
overcrowded classes (Bailie and Fitzgerald 2000), perceived difficulty of engineering degree (Ahmed et al. 2015),
and bad grades and insufficient comprehension (Wolffram et al. 2009) are some of the underlying reasons for
students to drop-out of engineering degree programmes.
Contrary to the above, engineering textbooks and curriculum have been overloaded with a higher level of
knowledge than ever before. Presently, the complexity of engineering education does not match with the existing
knowledge level of most recruited students when they are accepted into engineering departments.
Except China, India and few developing countries like Turkey, engineering degree enrolments are constantly
decreasing. This is a well-accepted issue in most parts of the world (Prietoa et al. 2009; Davis et al. 2012; Salas-
Morera et al. 2013; Li et al 2008; Gattis et al. 2003; Alpay 2013). China, India (The IET 2008; Gereffi et al. 2008,)
and Turkey (CoHE 2014) have increased the number of engineering enrolments of their universities by taking
concrete policies. For example, in 2011, Turkey’s higher education gross enrolment ratio is reported to be 61%.
This ratio was 61% in UK, 57% in France, 95% in USA, 76% in Russia (based on 2009), 101% in South Korea
in 2011 (Çetinsaya 2014).
The increased engineering enrolments in developing countries including China, India and Turkey are facilitated
by the reduction of entry qualifications to engineering degrees. This resulted in accepting students with relatively
weak in mathematics and sciences to engineering departments. The overall result is less qualified engineering
graduates. This is demonstrated in India by the results of AMCAT tests. According to National Employability
Report by Aspiring Minds of India (2011), 30% of the country’s engineers cannot solve a simple probability
problem and 42% lack mathematical skills for simple transactions, such as counting and arranging, and would
probably face difficulty in doing basic engineering calculations (Report by Aspiring Minds 2011; As of May 6,
2012, Mail Online India stated on its website).
A decline in the numbers of qualified students enrolling to engineering degrees in developed countries also
resulted in accepting students with relatively weak math and sciences into engineering departments. As a result of
this, the discussion on methods to improve mathematical skills of engineers in the workforce has been opened at
late 2000s (MEI/IET joint conference 2007). Prieto et al. (2009) stated that there has been a decline in the study
of engineering and the enabling sciences in universities and schools in many western nations. They concluded that
the continuing drop in high school student enrolments in higher level mathematics exacerbated the situation and
caused a shortfall in scientific and technical capabilities.
This conflict between the education process and the student ability has been adequately accepted, and the
literature has discussed the issues, but it has not provided remedies. Now, less qualified engineering graduates
are becoming prevalent in most parts of the world including Turkey. Actually, the underlying reasons can be
investigated by breaking down the problem into subcomponents. Then some remedies and solutions could be
identified and applied to solve the issues. Therefore, in this paper, it is aimed to reveal the reasons for the issues
at the course level that affect the qualification of mechanical engineers (MEs) so that these can be addressed
properly to re-balance the conflicting situation. However, the main intention is not only to identify and address
the issues of a specific course but also to provide a systematic method that may be applied to refine and simplify
courses of ME curriculum, and provide better structural integrity for students’ success in profession.
The specific university course explored in this work is the ME design (MED) course (MEDco). The term
“course”, used throughout in this work, refers to a particular module within the programme. MEDco, which is
called as Machine Elements, is a two-semester (ME-351 and ME-356 in the fall and spring semesters respectively)
compulsory course in the 3rd year of the Bachelor’s Degree program of ME education globally. On average across
countries, this is a three hours of lecture per week in the classroom and/or laboratory. It aims to teach how to
design the basic components of a machine, such as the design of gears, shafts, brakes etc. During the design activity
of a particular component, the components are sized by relating stress to geometry and load (Force, moment etc.)
considering safety and cost. MEDco was selected because;
 Most courses of ME education are burdensome and demanding for students and MEDco is typical.

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 It synthesises courses taught earlier within the mechanical engineering degree curriculum, such as Engineering
Drawing, Materials Science, Strength of Materials, Mechanics including statics and dynamics.
 The difficulties encountered by students whilst applying their MEDco theoretical knowledge to a complete
machine design project in ME project (MEP) course (rather than the design of a particular component) can
be evaluated in a machine design project course as an output of MEDco.
In this work, ME has been specifically looked into at top-down manner in Turkey. It investigates the possible
reasons for the reduced knowledge level of engineering graduates using a systematic method that relies on
hierarchically decomposing MEDco into its subassemblies. The issues related to the difficulties encountered in the
latest version of the textbooks have been examined in this work. These are handled through four levels. The level
1 contains “textbooks”, “MEDco success”, “project ability/adequacy” and “success factors”, each of which has
also components at low levels. Level 2 contains 8 subassemblies. Level 3 is the top-down design, which is machine
design level, while level 4 is the bottom design that is component design level. This work only concentrates
“textbooks”, “MEDco success”, and “project ability/adequacy”.
In addition, all the empirical evidences of the work are verified using three sets of data; accountability
measures, a qualitative data and a survey. The qualitative data obtained from 98 ME students, aged between 22
and 26, participated in the study voluntarily from the year of 2005 to 2015 periods. 91% of students were male,
and 9% of them were female. A total of 85 ME students in the spring term of 2016, aged between 22 and 27
contributed to the survey study out of 419. 11% of them were female. Finally, we conclude that students cannot
be held totally responsible and fully to blame for the reduced qualifications in engineering education as most of
the low level factors contribute to the issues that are related to various authorities. Bearing in mind the lack of
studies concerning the reasons for the issues at the course level, this study could be regarded as the first attempt to
reveal the issues in engineering by looking into the problem from the student’s perspective.
Mechanical engineering education in Turkey
ME is the discipline that applies the principles of engineering, physics, and materials science for the design,
analysis, manufacturing, and maintenance of mechanical systems. According to Budynas and Nisbett (2011),
“mechanical engineers are associated with the production and processing of energy and with providing the means
of production, the tools of transportation, and the techniques of automation”.
Course contents in ME are usually set according to ME requirements by accreditation societies of each
countries such as ABET in the USA, EUR-ACE system in the European Union and MUDEK in Turkey. Even
though there may be some differences in course structure diagram, the core courses of ME subject include MED,
mechanics, kinematics, thermodynamics, materials science, structural analysis, production and energy.
Universities in Turkey integrated into the Bologna Process in 2011. MED course is taught in the third year of
ME education at the ME department in the University of Çukurova, Turkey (Website of Information
Package/Course Catalogue). Mode of Delivery in all courses is face-to-face and the medium of instruction is
English. The department provides both day time (from 08:00 to 17:00) and evening education program (start after
17:00 till 23:00), each accepts 80 students.
Method used to identify and verify the possible reasons for the issues in MEDco
Process decomposition method is applied to MEDco for the identification of the possible reasons of the conflict
between the education process and the ability level of recruited students. Then accountability measures are used
to investigate pass grade percentages. Finally, the empirical findings of the work are verified using a two stage
case study, and a survey data obtained from ME students in Turkey.
The method of hierarchical process decomposition, which is a well-known technique to solve complex
engineering problems, is adapted here. The method relies on decomposing a process (parent diagram) into
subcomponents (child), and then into its components (or child diagram of its own) at lower level. In this way, each
process box of a decomposition may also be decomposed into another full decomposition for a better investigation
of issues. This can then be used to reveal the possible reasons for the issues in order to analyse these at the bottom
level. Then remedies to the related issues can easily be obtained.
Fig. 1 illustrates the application of the method to ME curriculum, which consists of various courses. This means
that it is already hierarchically decomposed into its subassemblies for teaching ME degree. As the work
concentrates in MED course, then it is decomposed into another full decomposition to show greater detail. For
example, the factors that may directly affect the MEDco are considered as “Textbooks (1)”, “MEDco success (2)”,
“Project ability/adequacy (3)” and “Success factors (4)” at level 1. Each of these has also components at lower
levels. Based on the method, the issues of MEDco are revealed at four levels.

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Fig. 1 Hierarchical process decomposition of ME for revealing reasons of issues in MEDco.
The work concentrates on the textbooks, which is the first process box of the parent process. It closely inspects
and evaluates the textbooks of MEDco considering their number of chapters and corresponding pages, the time
allocated for teaching, type of teaching examples used for the overall completeness of teaching. 3
The specific course explored in this study is MEDco, but MEP course (MEPco) related issues are also
considered as seen in Fig. 1. This is because students apply their MEDco knowledge in MEPco for combining of
separate elements of a machine to form a coherent whole. Hence performances of students in MEPco are mirrors
of understanding or cognition issues, and it is the indicator of the teaching performance in MEDco. Three different
sets of data are collected for both courses. The first data set was obtained by using the records of yearly assessment
results of MEDco. It gives percentage of students gaining a pass grade of MEDco. These are discussed under the
second process box of the parent process which is “MEDco success”. Furthermore, preferences by students on the
use of (textbook or American Gear Manufacturing Association (AGMA)) gear design approaches for gearbox
design in MEPco were obtained.
“Project ability/adequacy”, which is the third process box of the parent process, is decomposed into two at
Level 2. One of them is “machine projects (3.1)” in MEPco. Studies for this part aim to illustrate the complexity
of a complete machine design process for the students. This is demonstrated on a gearbox as machine design
example. Level 4 studies are then carried out to reveal the issues on the design of three main components of the
gearbox such as gears, shafts and rolling contact bearings (RCBs) by deeply searching MEDco textbooks and
technical standards for the variety or the types of design approaches, their cognitive and computational workloads.
In addition to the above, coherencies on the design results of five gear design approaches are investigated using
dimensionless numbers to show relative gear tooth volume percentage differences on the results of gear design.
This part of the study intends to show contradictions on the design approaches that cause dilemma for the students.
Furthermore, overall difficulties confronted by students during the design of a shaft and selection of a RCB are
briefly highlighted.
Verification of level 1 to 4 studies cannot be truly made only relying solely on accountability measure for pass
grade percentages (class success rates). Hence, the second sets of data, which provide difficulties confronted by
students during the machine design/projects, were collected from the students based on the informed consent
Bottom Design
Level (BDL)
Top-Down
Design Level
(TDL)
Common
Factors for
BDL
Level (4)
VERIFICATIONS BY STUDENTS
Component
1.3.2.1
Complete
Machine
1.3.2.2
Process/
Flowchart
Availability
Technical
Standards
Computational
Loads
Textbooks
Approaches
Simplicity/
Difficulty
Coherency
of Results
Validity/acce
ptability of
approaches
Course Level (0)
Level (2)
Level (1)
ME Education
- - - - -
Mechanics
Kinematics
Thermodyn.
MEDco (0)
Materials Sc.
- - - - -
Textbooks
(1)
MEDco Success
(2)
Project
ability/adequacy (3)
Success Factors
(4)
MEPco
Success
(3.2)
Curriculum
& others
(4.1)
Social
Factors
(4.2)
Placement
scores
(4.3)
Machine
Projects
(3.1)
Number/
Chapters, etc.
(1.1)
Contents and
Term Time
(1.2)
Example
Types
(1.3)
Analysis
(1.3.1)
Design
(1.3.2)
- - - - -
Gearbox
Design
(3.1.1)
- - - - -
Component
1.3.1.1
Complete
Machine
1.3.1.2
Gear
Design
3.1.1.1
Shaft
Design
3.1.1.2
Bearing Selec.
/Des.
3.1.1.3
Level (3)

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process. 98 MEPco students participated voluntarily in the study. Written statements of students as qualitative
data were collected and classified properly. Then percentages (%) of response frequencies of each class of the
statements provided by students were also determined. These allowed the derivation of a list of issues from the
perspective of students without the risk of influencing attitudes of students (as this could happen with a survey).
In the next stage of the study, written statements of students as classified “qualitative data” obtained from the
MEPco, was included in a survey as statements (in the “Gear design approaches” section (4) of the survey) together
with the empirical evidence obtained during the decomposition. Both were used in a voluntary survey to show
whether the findings were sensible or meaningful. This allowed obtaining the third set of data that is used to verify
most of the empirical findings of the work.
The survey has 6 sections, starting from a more general to very specific one. These are “1-General” 2-Related
to “Design of shafts”, “3-Selection of rolling contact bearings”, “4-Gear design approaches”, “5-Design of a
gearbox” and “6-Additional comments”. It also contains a short aim, and a return address printed on it.
The survey based on the informed consent process without requiring names of contributors was introduced to
third year MEDco and fourth year (85) ME students in 2016 including night classes. All the participants were
asked to fill in the “General” section of the survey. However, as the survey was asking quite details regarding
various topics, the students were requested to contribute only to the sections in which they have prior experience.
As a result of this, the number of participants (provided at the last column of the tables) varies for each statement
accordingly. This meant that students who carried out compulsory shaft design project in MEDco only contributed
to the survey sections from 1 (General) to 3 (Selection of rolling contact bearings) and to the section 6 (Additional
comments). Those students, who carried out gearbox design project in MEPco, found themselves eligible for the
all sections of the survey.
The survey questions ranked each statement on a 5-point Likert scales (strongly agree (SA), agree (A), neutral
(N), disagree (D) and strongly disagree (SD)) were used to examine how strongly the students agree or disagree
with the statements. Responses of “SA” and “A” are classified as favourable (F), and “D” and “SD” as
unfavourable (U). Each of the responses of students was assigned to the appropriate category by counting the
responses. Frequency distributions for each category are then used to find the percentages for the each category.
The followings provide the application of the method to identify the possible reasons for issues at each level.
Textbooks (1)
Before handling the issues at the textbook level, first of all, the differences between “the machine design” and “the
MEDco” are identified. “Machine design” refers to a much wider context including the use of knowledge obtained
from “MEDco” together with the knowledge of other particular technical courses of ME such as fluid power, heat
transfer, thermodynamics, etc.
Most MEDco textbooks provide a reasonably simple design approach together with a design approach of
international or national technical standards such as International Standards of Organisations (ISO) or AGMA
standards depending on the nation or target readers of the textbook writer.
During the design, designer/students use many mathematical expressions, design knowledge and engineering
data provided in MEDco textbooks. Two of the well accepted and utilised international main textbooks considered
in the study are listed in Table 1. Considering the process decomposition, “Textbooks (1)” of Fig. 1 is further
decomposed into three subassemblies to reveal issues. These are “Number of chapters etc. (1.1)”, “Contents and
term time (1.2)”, and “Example types (1.3)”.
Number of chapters, etc. (1.1)
The rapid ongoing developments have led to the expansion of contents of two well accepted and utilised
international main textbooks for the course, which is provided in Table 1 with a summary of their total number
of chapters and numbers of pages in each version.
Table 1 The length of well accepted international main textbooks for MED courses
Shigley’s Mechanical Engineering Design
Juvinall & Marshek’s Fund. of Machine Comp. Design
Version and Year
No.of Chapters / Total Pages
Version and Year
No.of Chapters / Total Pages
1st-1986
17 / 699
2nd-1991
20/ 804
5th-1989
18 / 779
3rd-2000
20 / 888
6th-2003
18 / 1299
4th-2006
19 / 832
7th-2004
18 / 1030
5th-2011
20 / 899
8th-2008
20 / 1055
9th-2011
20 / 1088

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Total pages for ‘Shigley’s Mechanical Engineering Design’ increased by more than 66% from the 5th version
(1989) to the version 6th (2003). In 7th version, a year later, there was a reduction of about 21% in the printed pages
(maintaining the same page size, form and font sizes of the earlier version). The reduction on the text was made
by removing non-essential elements, such as statistical oriented examples and problems, and advanced topics. For
allowing students to quickly gain a basic requirement in the subject matter, the chapters were also condensed and
some practical examples were added in the same version (Shigley et al. 2004). It is stated that the modifications
were made by reducing ME knowledge detail. This was possibly to compensate for the reduced science and
mathematics competencies of the recruits. However, when the first and the last versions in Table 1 are compared,
it is seen that the last version of the most popular textbook contains an additional 3 chapters and more than 300
pages. This brings out a question; as the entry qualifications are steadily being reduced, is this content still
appropriate? Furthermore, the studies of this work showed that the textbook related issues still prevails even though
the modifications made on the last versions of the textbooks. Therefore, the textbook related issues are investigated
in this work considering the latest versions.
Contents and term time (1.2)
MED course textbooks contain about 20 chapters, each averaging over 50 pages but 28 weeks per year excluding
examinations are available for teaching. This is more or less the same in most USA universities and all EU
countries that are included in the Bologna process. The allocated time is obviously not sufficient to raise the new
recruitments competence, and it brings out some cognition issues resulting in high attrition rates as discussed
previously.
Example types (1.3)
The textbooks used in the field have been analysed for the types of examples provided for the students. Many of
the textbooks contain examples generally concentrating on the use of formulas in simple problems. Most of the
examples are based on the analysis of a “design problem”. In this type of problem, students carry out the problem
using related expressions and formulas to evaluate how “safe” the design is. This is the easiest problem because
the problem contains many inputs except one or two unknown parameters either size or factor of safety. However,
graduates in the professional career are employed to design various machine components. Most of these design
problems require many decisions, assumptions or selections of various parameters requiring iterative solutions.
Then the types of design and analysis examples are further scrutinized. As seen in the Level 3, this is first
subdivided into two as “Analysis (1.3.1)” and “Design (1.3.2)”, and then each again subdivided into two at Level
4. Contrary to the expectations, the studies at this level showed that majority of well accepted textbooks either do
not contain complete machine design examples or only contain limited examples in each chapter devoted to
teaching of the design of a particular mechanical component. Moreover, each of the particular component design
is taught separately in isolation from the context of a complete machine.
MEDco success (2)
“MEDco success (2)” is the second subassemblies (child) of MEDco at level (1) in Fig. 2. MEDco success of
students will reveal issues at lecture level. A pilot study was conducted to obtain the first set of data by checking
the percentage (%) of students gaining a pass grade (success rates) in both terms. The pass grade percentages for
ME-351 were found to be lower than ME-356 (see Figure 2). Most of the students find first term course (ME-351)
more difficult than ME-356. An important reason stated by students for the MEDco is “Theories available for
static and fatigue design of mechanical components are not easy to internalize, and when it comes to apply the
theories into design problems, we are getting lost”. Students stated that main reason of low success for both term
courses is “The course heavily depends on earlier courses. By the time we realised this, it was the time for midterm
exam”. This is true. The first term course heavily depend on sophomore year courses such as “Engineering
Mechanics” (Statics & Dynamics), “Strength of Materials”, “Materials Science” and even to fundamentals of
“Technical Drawing”. In addition, the second term course is connected to both the sophomore year and to the ME-
351. Similarly, percentage of students gaining a pass grade in the final exam are worse than the resit exams in each
course. As a result, the number of attending students raised from 80 to 159 for fall and 131 for spring term lectures
respectively in 2015, even though relative evaluation system has been used.
In the last five years, the lowest marks for the pass grade are gradually reduced due to lowering success
performance of students in the exams. For the first time in the last 20 years of teaching experience, RES grading
system further lowered the value of passing mark of DD in 0 to100 grading scale in spring term of 2014. When a
student receives DC or DD in a course, s/he is considered as successful only if her/his (general) grade point average
(GPA) is 2,00 or above.

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Fig. 2 Percentage of students gaining a pass grade in ME-351 and ME-356 obtained in level 4 studies.
Project ability/adequacy (3)
The abilities of students in projects were searched to see the issues and outcomes of MEDco in MEPco. “Project
ability/adequacy (3)” of Fig. 1 is further decomposed into its own child or subassembly diagrams. These are
machine projects (3.1) and MEPco Success (3.2). The findings of both child diagrams discussed below will reveal
issues related to project ability/adequacy of students.
Machine projects (3.1)
Students perform a number of machine design projects during ME education. An engineering design student has
to produce a solution to the machine design problem, which has many boundary conditions, some of which are
either abstract or variable. Machine design process, which is initiated as top-down design activity, is an open ended
process. As an example of a complete design process, a gearbox is considered in this work. Therefore, a sub-
parent diagram of “Machine projects (3.1)” is decomposed into child diagrams to consider “Gearbox design
(3.1.1)”, for the selected project as given in Fig. 3.
Gearbox design (3.1.1)
Simplified design process of a simple spur gearbox is given in Fig. 3 to illustrate the complexity of the process,
and to emphasise the concealed issues that have to be confronted by the students. In each step of the process,
specific design considerations must be determined. The current teaching curriculum relies on student learning
(with class projects/homework or projects given in MEPco) to teach the process given in Fig. 3 rather than
providing this knowledge in the MEDco textbooks in the form of process flow charts.
Most students without experience of a similar project cannot envisage the activities of the design process
outlined above. As a consequence, they can barely carry out a successful machine design. For example, most
students are not aware of how and where the forces, shown in step 6 of Fig. 3, come into a shaft in order to be able
to design it. Design steps of Fig. 3 are indicated below to analyse each step in the gearbox design process to obtain
empirical evidences for the issues that directly affect success of students.
Gearbox design is further decomposed into three diagrams following the steps given in Fig. 2. Complexity at
the bottom design level will be highlighted to reveal the issues on the design of three main components of the
gearbox that are “Gear design (3.1.1.1)”,” Shaft design (3.1.1.2)”, and “Bearing selection/design (3.1.1.3)”. The
findings are discussed below.
Gear design (3.1.1.1)
In order to perform a gear design, varieties of national and international standards and/or MEDco textbooks having
different levels of difficulty are available. There are vast numbers of sources of gear design approaches. Table 2
provides some of the well-known and most commonly used sources of gear design approaches. Other textbooks
are also available (see Childs P.R.N., 2013; Ugural A.C., 2003; Jelaska D.T, 2012; Mott R.L., 2003; Babalık F.C.,
2010). In this study, three MEDco textbooks (Shigley’s Mechanical Engineering Design 1st Metric Edition and 9th
Edition, Juvinall & Marshek’s Fundamentals of Machine Component Design 5th Edition) and two standards
(American National Standards Institute (ANSI)/AGMA Standards and ISO Standards have been considered to
provide challenges, which students can experience.
0
10
20
30
40
50
60
70
80
2010 2011 2012 2013 2014
Percent (%) of students gaining
a pass grade
Years
ME351 Final ME351 Re-Final ME356 Final ME356 Re-Final

9
Fig. 3 Simplified illustration showing the complexity of a gearbox design steps used for the studies of level 1 to
4.
Cognitive and Computational work loads
The five selected gear design approaches for bending fatigue failure were analysed to obtain the prescribed amount
of cognitive and computational work. Table 2 also presents the cognitive loads of the approaches for spur gear
design considering the number of relevant pages, design and sub-design variables. It is easily seen on Table 2 that
the knowledge of textbook approaches is shorter in terms of the number of pages with limited number of design
and sub-design variables, which are simple and easy to understand. In contrast, the national and international
standards are extremely long in terms of the number of pages including more challenging, complicated and time
consuming design and sub design variables to obtain and work with.
Table 2 Cognitive work load of the gear design approaches for bending fatigue failure
DESIGN APPROACHES
Number of
relevant pages
Number of Design
Variables+Sub
Design Variables
Mechanical Engineering Design 1st Metric Edition (Shigley’s J.E.,
1985)** (SH1)
13
6+0
Shigley’s Mechanical Engineering Design 9th Edition (Budynas
R.G. and Nisbett J.K., 2011) (B&N)
11
4+0
Fundamentals of Machine Component Design 5th Edition (Juvinall
R.C., Marshek K.M., 2011) (J&M)
9
6+0
ISO 6336 Standards (ISO)
225
16+23
ANSI/AGMA 2010-D04 Standards (AGMA)
59
11+19
** Introduces the design of a spur gear clearly
To highlight the computational complication for the design of each gear couple, the related equations are
arranged for the purpose of design iterations to find face width (F or b) as presented in Table 3. The parameters,
some of which are variable, presented in Table 3 correspond to the referred literature. One of the main problems
here is that the design is iterative, and any selected design approach of Table 3 needs to be repeated number of
times to find gear module (m). At each iteration, all variables have also to be changed by the designer until suitable
face width has to be obtained for a selected gear module that directly determines tooth size. As seen from the Table
2 and 3, the amount of computational and cognitive work load is extremely high for ISO and AGMA technical
standards.
ITERATIVE
DESIGN
(1) Select a design approach
(3) Design Gears (find face width
and module)
(2) Determine gear
box design concepts
(4) Find gear forces
and reactions forcers
(5) Initiate shaft design by using
gear bearing forces
(6) Find reaction forces on a shaft
(7) Design shaft(s)
(8) Use reaction forces to select
bearings for shafts
(9) Assembly all components
to finalize design
SPUR GEAR DESIGN
CONCEPT
CREATION
ITERATIVE
DESIGN
USE OF CREATIVITY AND ENGINEERING KNOWLEDGE

10
Table 3 Complexity of equations under bending fatigue failure to determine design outputs for face width
Design
Approaches
To obtain face width
SH1
F= Wt.nd.Ko.Km
Kv.m.J.𝑆𝑒
B&N
F= Kv.Wt.nd
m.Y.𝑆𝑒
J&M
b= nd.Ft
m.J.𝑆𝑒
.Kv.Ko.Km
ISO
b= SFmin.Ft
σFlim.YST .YNT.Yδ rel T.YR rel T .YX.mn
.YF.YS.Y.YB.YDT. KA.KV.KF.KF
AGMA
b= SF.Ft
σFP.mt.YJ
.Yθ.YZ
YN
.KO.KV.KS.KH.KB
The detail given above is only the half of the design process; this is because the results of the design must also
be checked for surface fatigue failure, requiring different set of expressions that are more ambiguous than those
given in Table 3. Additionally, if the design results for surface fatigue failure are not satisfactory, the design is
iterated until all conditions are satisfied.
Coherence of the design results
This part intends to reveal the coherence of the results of gear design approaches which also creates issues for
students. Dividing the design results of any textbook design approach by the results of a national or international
gear standard, relative comparisons are possible. This is made by performing iterative design calculations to
generate design data for module (mi or m0) and face width (Fi or Fo) for each selected approach. Then
multiplications of module and face width values are combined to obtain a geometrical value (GV) at the cross-
sectional area of the pitch diameter. This is because half of the circular pitch (p/2=π.m/2) approximately equals to
tooth thickness in SI units. The design results of the simple textbook approaches (mi times Fi) were rated to the
design results of AGMA Standards (m0 times F0). Thus, it provided a new dimensionless parameter which is called
as “Geometric Rating Number” (GRi). It is defined specifically as GRi= (mi.Fi) / (mo.Fo).
This allowed ranking the design approaches. Table 4 provides the mean rankings that were obtained using 0.5-
1000 kW power range for spur pinions with the most common pressure angle of 200 under bending fatigue failure
and with interference-free minimum pinion teeth numbers for comparison purposes of gear design approaches.
Two sets of GRi numbers for the gear design were obtained using the lowest and the highest strengths of the
materials given in Table 4.
Table 4 Minimum mean GRi numbers for the gear design approaches (Uzay 2014)
Geometric Rating Numbers for the Approaches with
Two Types of Material:
GRi
Min. strength
Max. strength
SH1, GRSH1
B&N, GRB&N
0.93
0.46
0.67
0.45
ISO 6336 Standards, GRISO
0.63
0.61
J&M, GRJ&M
0.88
0.86
ANSI/AGMA 2101-D04 Standards, GRAGMA
1.00
1.00
GRi results given in Table 4 vary between 0.45 to 1.00, which indicates considerable relative gear tooth volume
percentage difference or weight variations amongst the design approaches. This highlighted a lack of coherency
of the design results given by the gear design approaches. In contrary, finite element analysis carried on the spur
gear design well-matched to the design results of ISO gear standards based on the bending fatigue failure (Uzay
2014). This means that ISO gear design will give 39% less volume than AGMA as the relative volume percentage
difference (GRi) between the design results of AGMA standard and ISO standard found to be (1-0.61) 0.39%. This
brings another problem on the reliability of available gear standards. This will indicate that there are still unsolved
contradictions between the standards.
Shaft design (3.1.1.2)
Issues for students also exist for the design of shafts. Shaft design problems requiring many design decisions are
also iterative. Similar to gear design approaches at least eight design approaches containing different expressions
are available for the shaft design within the course textbooks, ignoring brittle materials (Budynas and Nisbett

11
2011). Furthermore, the approaches give different design results. The multitudinous of each choice obviously
complicates teaching and hinders students understanding and makes teaching more challenging.
Bearing Selection/design (3.1.1.3)
Many rolling contact bearing (RCB) manufacturers provide their own specific formulae. Textbooks usually
select one manufacturer’s information and formulae. This limits the students to choose any other manufacturer.
Worse than that, when other manufacturer’s formulae in a RCB catalogue is chosen, the student is further confused
with the use of different basic load rating that defines the life of a RCB. The life is rated either for 106 revolutions
or 90(106) revolutions depending on the chosen manufacturers. Therefore, moving from a manufacturer to another
or searching to find the equivalent sizes causes problems for the RCB selection due to lack of technical standards
to achieve uniformity.
MEPco Success (3.2)
“MEPco success” takes place in the level 2 of hierarchical process decomposition as seen in Fig. 2. Studies in this
part intend to obtain the second set of data from the students of MEPco. MEPco with a small number of students
up to 8, four lecture hours a week, is compulsory for the senior students in fall and spring terms.
Assessments of student projects were carried out based on the project file, weekly progress shown on MEPco,
and on the oral presentations given at the final exam by the students. Mean class pass grade percentages (success
rates), around 75% to 90% in the last 10 years of MEPco, have not been affected much by the reduced entrance
qualifications but the effort and the work put in to supervising have greatly increased.
Success factors (4)
“Success factors,” which is the fourth child of the parent diagram of Fig. 2, is further decomposed into three
children to reveal issues related to “Curriculum and others (4.1)”, “Social factors (4.2)”, “Placement scores (4.3)”
but it is not discussed in this work.
Verification by a two stage case study and a survey
A two stage case study was carried to evaluate the difficulties encountered by students whilst learning about gear
design from the years of 2005 to 2015. Those students who have selected a gearbox design project are reminded
to scrutinise the related design approaches in the MEDco textbooks.
In the first stage of the case study, ME students, carrying out a gear design project within their MEPco, were
given options to select either a textbook approach or an AGMA gear design approach. The selections of students’
design approaches were collected from the completed projects and documented.
Most of the students preferred textbook design approach due to its ease of use and simplicity. Only 11 students
out of 119, in 10 years period, selected the AGMA gear design approach. This means 10.18% were interested in
learning detailed gear design process of AGMA standards. During the supervising process, all students experienced
problems but those using the AGMA standards got stuck. These were successful if they worked together with the
students using textbook design approach. Those students who selected the use of AGMA design approach were
either highly motivated students or those with good GPA.
In the second stage of the case study, MEPco students were invited voluntarily to list down their confronted
difficulties in their project file as a separate sheet of information. Then, students’ written comments on gear design
approaches were collected. Informal statements of students were interpreted by considering what they signify. For
example, statements provided by a student (İlhan Y.) were; “Not knowing which way to follow comes at the top of
the most important anxieties of mine. Steps must be known absolutely. You must know where to start the
calculations. For example, there must be a flow chart, a tree diagram guide”. It signifies the lack of understanding
and possibly the students’ desperation. Qualitative data, which are similar to the above, have been classified, and
then interpreted to cover all. 98 MEPco students contributed to the study, 11 of whom were from the AGMA
design approach group. Table 5 summarises the qualitative data collected from the students by ignoring
irrespective ones and without considering gender. It also contains percentages of response frequencies provided
by students for each class of the statements, and given in round brackets. The two statements at the top of the Table
5, which are “couldn’t figure out where to start with” and “Design flow chart is not available,” interpret the group
of similar data collected from both (Textbook and AGMA) gear design project groups.

12
Table 5 Students’ data on gear design approaches with their response frequency (%) percentages collected from
98 MEPco students.
Students’ data on the use of gear design approaches
Textbook design approach (87 students)
AGMA design approach (11 students)
(31) Couldn’t figure out where to start with (45)
(29) Design flow chart is not available (36)
(15) The difference between design for bending strength and surface strength are not stated, the designer
does not know where to start and why (36).
 Reasonably easy to carry out design (12)
 The approach is too long, containing 25 modification factors
(27)
 The design is shorter and self-teaching
(14)
 It was not clear to select appropriate sub-factors for modification
factors (18)
 It allows itself to computer
implementation (11)
 Internalization of factors including safety factors are difficult (9)
 Many factors are to be read from table, diagram or be calculated
depending on various other parameters but not clearly indicated
(18)
 Finding of many parameters in iterative design again and again
is really tiring (36)
 Modification factors are not suitable for software
implementation for computer (27)
 Often you forget what you are doing due to the work load of
calculations (27)
The findings of Table 5 were included in the “Gear design approaches” section of the survey as discussed in
the method.
The response of students to the survey statements strongly verified most of the empirical findings obtained for
“Textbooks (1)” related issues in the “General” section of the survey. Table 6 provides survey statements and its
findings. For instance 86.9% (F) of students responded that the lecture is heavily loaded, and 89.4% (F) accepted
that lecture hours are not sufficient for teaching. Overall, over 80% (F) students agreed that the textbooks contain
limited examples usually based on the analysis of the problem and not sufficient for a complete design of machine
without sufficient support so the textbooks do not provide the expected self-confidence to students. Even though
the survey statements, given in Table 6, contained contradictions in item “e” and “f”, the results of respondents
indicated a good agreement for these items too.
The negative effect of the reduced lecture hours in the survey were also measured using the answers given to
item “j”. The survey results, provided in Table 6, verified that 89.4% (F) students agreed that lecture hours were
not sufficient while only 7.1% (N) was neutral and 3.5% (U) disagreed.
Table 6. Surveys statements and findings in percentages related to “General” section
Statements
SA
%
A
%
N
%
D
%
SD
%
NP
a)-In general, the course content is heavily loaded.
44.0
42.9
8.3
2.4
2.4
84
b)-Lecture hours are not sufficient to learn the details of each
chapter.
63.5
25.9
7.1
3.5
0.0
85
c)-The textbooks contain examples generally concentrating on the
use of formulas in simple problems.
36.9
51.2
8.3
1.2
2.4
84
d)-Component design is taught separately as isolated from a
machine.
45.9
40.0
8.2
4.7
1.2
85
e)-Most of the examples are based on the analysis of a “design
problem” rather than “designing a machine” member.
47.1
43.5
5.9
2.4
1.2
85
f)-Most of the examples are based on the “design problems”.
8.2
15.3
12.9
41.2
22.4
85
g)-Majority of textbooks do not contain complete machine design
examples.
63.1
23.8
6.0
4.8
2.4
84
h)-Majority of textbooks contain limited example(s) in each
chapter devoted to teaching of the design of a particular mechanical
component.
41.2
44.7
10.6
3.5
0.0
85
i)-Flow charts describing design steps of a particular machine
element would be extremely useful when designing components.
69.4
23.5
2.4
1.2
3.5
85
j)-Lecture hours are not sufficient to teach details of each chapter.
63.5
25.9
7.1
3.5
0.0
85

13
Key: SA: Strongly agree; A:Agree; N:Neutral; D:Disagree; SD:Strongly disagree; NP:Number of participants
The empirical findings of “Shaft Design (3.1.1.2)” were verified in related section (“Design of shafts”) of the
questionnaire. Table 7 provides survey statements and its findings. 91.2% (F) of students responded that too many
shaft design approaches are available and 92.5% (F) agrees that this creates difficulty in learning. Items “c” and
“e” interrogates student’s self confidence in shaft design considering the knowledge provided in the textbooks.
83.8% (F) of respondents are not satisfied with the knowledge provided in the textbook while 77.3% (F) of students
claimed that they could not carry out shaft design project on their own. The finding in item “e” also matches with
finding of item “a” in “Design of a gearbox” section in the survey, given in Table 10. This means that students
cannot carry a design task on their own. Finally, the demand for a flow chart describing design steps of a shaft
design in item “d” is favoured (F) 85.1%.
Table 7. Surveys statements and findings in percentages related to “Design of shafts” section
Statements
SA
%
A
%
N
%
D
%
SD
%
NP
a)-Too many design approaches are available
64.7
26.5
7.4
1.5
0.0
68
b)-Existence of too many design approaches make learning of shaft design
more difficult.
52.2
40.3
1.5
3.0
3.0
67
c)-I am satisfied with the knowledge provided in the textbook for shaft
design so I can carry out perfect shaft design on my own.
4.4
1.5
10.3
38.2
45.6
68
d)-Flow charts describing design steps of a shaft design would be
extremely useful when designing shafts.
59.7
25.4
4.5
9.0
1.5
67
e)- I carried shaft design project on my own without any support
7.1
4.8
10.7
44.0
33.3
84
The empirical findings of “bearing selection/design (3.1.1.3)” were verified at the “Selections of RCBs” section
of the questionnaire. Table 8 provides survey statements and their findings. 80% of students favoured (F) assertion
that the textbooks do not clearly sign post when to use RCB or journal bearings. 52.1% of students agreed with
(F) for item “b”, and 84.5% (F) agrees that flow charts describing selection steps of a RCB would be useful in item
”c”. An overwhelming 95.7% (F) of the students agreed to item “d” while only 1.4% (N) is neutral and 2.9% (U)
is strongly disagree. The result of item “d” may be interpreted as the lack of details in textbooks that may stop
most students to perform proper design projects.
Table 8. Surveys statements and findings in percentages related to “Selections of RCBs” section
Statements
SA
%
A
%
N
%
D
%
SD
%
NP
a)-Textbook clearly signs post when to use RCB or journal bearings.
5.7
4.3
10.0
34.3
45.7
70
b)-The use of different basic load ratings (106 or 90.106 rev.) suggested by
RCB manufacturers creates confusions
28.2
23.9
12.7
21.1
14.1
71
c)-Flow charts describing selection steps of a RCB would be extremely
useful when selecting RCBs.
54.9
29.6
1.4
12.7
1.4
71
d)-I did not know that I would modify shaft dimensions based on the
selection of RCBs until lecturer told us.
58.6
37.1
1.4
0.0
2.9
70
Table 9 provides the statements from item “a” to “p” used under the “Gear design approach” section (4) of the
survey together with the findings obtained from the respondents. 78.6% (F) and 64.3% (F) of students stated that
they couldn’t figure out where to start from when using textbook (in item “a”) and AGMA design approaches (in
item “b”) respectively. The demand for design flow chart is 85.7% (F) for textbook and 84.6% (F) for AGMA
design approach. Similar to the above, students were agreed to statements of “e” and “f” with 92.9% (F) and 71.4%
(F) for textbook and for AGMA design approaches respectively. The agreements to statements “j” to “p” except
“o” were also found to be in between 64.2 (F) and 78.6% (F). Statements of “i” and “o” interrogate computer
implementations of textbook and AGMA design approaches. 50.0% of respondents were neutral (N) in responding
to statement “o” while this is only 28.6% (N) for the statement “i”. This is probably due to the lack of experience
of the respondents on the computer implementation of each of the approaches. Contrary to the expectations, only
14.3% (F) of students in item “g” were in agreement that textbook design approaches were reasonably easy to
carry out. This supports the finding at item “c” where the demand for flow chart is found to be 85.7% (F). However,
most of the respondents (57.1% (F)) agree that textbook gear design approach is shorter and self-teaching for the
statement “h”.
One may argue that the number of respondents to “Gear design approaches” section of the survey is very
limited. This is true, but the statements were elicited from 98 students with reasonably high frequency percentages.

14
Secondly, only the qualified respondents were invited related to “Gear design approaches” and “Design of a
gearbox” sections of the survey.
Table 9. Surveys statements and findings in percentages related to “Gear design approaches” section
Statements
SA
%
A
%
N
%
D
%
SD
%
NP
a)-I couldn’t figure out where to start when using textbook design
approach.
28.6
50.0
7.1
14.3
0.0
14
b)-I couldn’t figure out where to start when using AGMA design
approach.
42.9
21.4
14.3
21.4
0.0
14
c) -Design flow chart is not available for the textbook approach.
71.4
14.3
7.1
7.1
0.0
14
d)-Design flow chart is not available for AGMA design approach.
61.5
23.1
7.7
7.7
0.0
13
e)-The difference between design for bending strength and surface
strength are not stated in textbook design approaches, the designer does
not know where to start and why.
50.0
42.9
0.0
7.1
0.0
14
f)-The difference between design for bending strength and surface
strength are not stated in AGMA design approach, the designer does not
know where to start and why.
35.7
35.7
7.1
21.4
0.0
14
g)-Reasonably easy to carry out textbook design approaches.
0.0
14.3
28.6
50.0
7.1
14
h)-Textbook gear design approach is shorter and self-teaching.
7.1
50.0
28.6
7.1
7.1
14
i)-Textbook gear design approaches allow themselves to computer
implementation.
0.0
28.6
28.6
35.7
7.1
14
j)-AGMA approach is too long, containing 25 modification factors.
42.9
28.6
21.4
0.0
7.1
14
k)-AGMA approach was not clear to select appropriate sub-factors for
modification factors.
28.6
50.0
14.3
0.0
7.1
14
l)-Internalization of modification factors including safety factors are
difficult in AGMA design approach.
7.1
57.1
35.7
0.0
0.0
14
m)-Many factors in AGMA documents are to be read from tables,
diagrams or be calculated depending on various other parameters but not
clearly indicated.
35.7
42.9
21.4
0.0
0.0
14
n)-Finding of many parameters in iterative design again and again is
really tiring in AGMA design approach.
28.6
50.0
14.3
7.1
0.0
14
o)-Modification factors of AGMA are not suitable for software
implementation for computer.
28.6
14.3
50.0
0.0
7.1
14
p)-Often you forget what you are doing in AGMA design iterations due
to the work load of calculations.
14.3
50.0
21.4
7.1
7.1
14
The empirical findings at the top-down design level were also verified at the “Design of a gearbox” section of
the questionnaire. Table 10 provides survey statements and its findings. 78.6% (F) of students responded that they
cannot carry out design projects on their own using only textbooks, and they don’t know the steps of a gearbox
design very well.
Table 10. Surveys statements and findings in percentages related to “Design of a gearbox” section
Statements
SA
%
A
%
N
%
D
%
SD
%
NP
a)-I can carry out design project on my own using only textbooks.
0.0
14.3
7.1
35.7
42.9
14
b)-When I started the gearbox design project, I knew the steps of a
gearbox design very well.
0.0
0.0
21.4
42.9
35.7
14
Results and discussions
Contrary to the global consensus on the enrolments for ME degree; the enrolments in Turkey have not yet
declined. Nevertheless, the ongoing condition will probably lead to it first in low profile departments. This, then,
brings about the closure of evening shift education programs as this is already the case in other engineering subjects
throughout Turkey by the decision of COHE, i.e. Textile, Mining and Geological engineering.

15
The complexity of ME education has been very well accepted as student enrolments decline in technologically
intensive industries of countries, and student entry qualifications to ME departments have been reduced globally.
In addition, high attrition rates (up to 50%) are now declared. The risk of having lower quality engineering
graduates and its negative effect on “research and development” activities were already discussed for Europe
(Kolari et al. 2008). In contrast, most of the effort was made to attract pupil’s interests into STEM subjects rather
than balancing the teaching materials, specifically the textbooks, to the ever reduced science and mathematics level
of recruited students. Nevertheless, mostly, recruited students’ low science and mathematics levels are blamed for
the reduced quality of engineering graduates.
Most recent studies have discussed the topic but these don’t go into as much detail as in this study. Hence, the
work in this paper carried out close inspection on the MEDco course, and then its outcomes in MEPco were studied
using the method of hierarchical process decomposition process. Factors that may directly affect the MEDco are
considered as “textbooks”, “MEDco success”, “project ability/adequacy” and “success factors” at the first level of
the decomposition.
The strongly verified survey findings are classified based on the first level decomposition, and these are
summarised below:
The textbook (1) findings are;
 Holism, which makes the textbooks too inclusive in knowledge, is an accepted philosophy.
 Inclusive knowledge in limited term times is not sufficient for full teaching of all chapters.
 Efforts to include the complete product or machine design process are not sufficient.
 Each of the particular mechanical component designs is included in isolation from the rest of the
chapters.
 Expressions are usually provided to perform analysis of machine components, but this hinders students
to perform design related computations.
 The majority of textbooks only contain limited design examples in each chapter, devoted to teaching of
the design of a particular mechanical element. But mostly these kinds of examples do not consider
designing a whole machine which consists of more than one mechanical element.
 As the difference between the “design” and “analysis of design results” are not clearly indicated, students
actually get confused.
 Even the latest versions of the textbooks need refining and simplification to remove unnecessary
complexity.
MEDco success (2) findings are;
 Turkey’s achievements in science and mathematics levels in PISA are getting better, similar to
technological countries, but a number of a share of the best students entering into ME departments are
constantly being reduced.
 The pass grade percentages of students in MEDco are in a decrease.
 The curriculum time table for MEDco is overloaded by many chapters, each of which contains a machine
member, is taught separately in isolation from the context of a complete machine.
 Constrained time table in MEDco is not sufficient for students to internalize the subject.
 Overcrowded classes reduce the yielding of teaching.
 The pass grade percentages rates are low even after resit exams, and this finding is in line with the
international findings provided in the literature.
 RES grading for the lowest passing marks of DD is extremely reduced in parallel to reduced placement
scores of the ME department.
 Three lecture hours per week of teaching MEDco is insufficient for the content of the MED.
Project ability/adequacy (3) findings are provided below for “machine projects (3.1)” at the top-down and bottom
design levels and “MEPco success (3.2)”;
Findings for “machine projects (3.1)” at the top-down design level (3) are:
 Design process of a mechanical element (part) and inclusive design process of a part in a machine/product
are not included in MEDco textbooks as flow charts. This is in line with the literature as shift from
teaching “focused on knowledge” towards teaching “about the process of engineering” are also advised
(i.e. engineering design & professional practice) (Report of MEI/IET 2007).
 Component design knowledge taught or learned in different courses are fragmented to carry out complete
machine design successfully.
Findings for “machine projects (3.1)” at the bottom design level (4) are:

16
 Expressions or equations used in design of machine members are overcrowded with many challenging
modifiers often causing confusion.
 Many design approaches, some of which are redundant, are provided in the same textbook for the same
mechanical component causes confusion.
 Case study of gears indicated that the complexity may not increase the accuracy of engineering
calculations. In some cases it may even bring out reliability issues including technical standards.
 There is a lack of coherence between the design results for the same mechanical component.
 As there are unsolved contradictions even between the technical component design standards, there may
not be any point including them and teaching them to undergraduates.
As seen in the findings of level 4 in Fig. 1, common issues, encountered by students in MEDco, have been found
related to process/flow chart availability, computational loads, coherency of the results, simplicity/difficulty,
textbook approaches, technical standards and validity/acceptability of approaches.
Findings for MEPco success (3.2) are;
 Excessive pressure of work load causes majority of students to select easy projects from less demanding
supervisors.
 Easier design approaches containing relatively simple mathematical expressions are preferred by the
students.
First two findings of MEPco success may be related to reduced qualifications or it may be general instinctive
behaviour or behaviour due to reduced qualifications. Even though an environment where practical exploration of
assembled, dis-assembled and cross-sectioned gearboxes are provided as an active learning environment to
students carrying on their projects, it did not cause any improvement on their projects due to the reduced
competence. The following findings show the specific issues that are still major factors effecting student success.
 Most students don’t know where to start when it comes to applying their knowledge on a complete
machine design project.
 The number of design project assignments is not sufficient to unite fragmented knowledge accumulated
over the four years of engineering education.
Teaching based on decomposing a degree subject into courses is essential and has been successful for decades.
However, it seems that structural integrity of ME education has also not been properly established yet.
Level 1 to 4 findings are mostly related to the unnecessary complicacy, and high demands of a ME education,
which is incompatible with ever reducing science and mathematics competence amongst recruited degree students.
All the reasons stated for level 1 to 4 can be solved by the authors of MED textbooks. Nevertheless, support is
needed for design codes and technical standards from related institutes such as Society of MEs, National Science
Boards, and educational authorities.
Conclusions
In this work, underlying reasons for the aforementioned issues on European and international perspective were
found as a common set of issues. The majority of the outcomes are also found to be irrespective of nation, even
though different economic, cultural, and social factors influence the education. Next, the “MEDco success findings
(2)” showed that the outcomes obtained from Turkish students match with the findings of the literature review
on the other countries. This indicates that reasons (or factors) for the issues have intercultural dimension. Now,
the reasons for issues that can be resolved are addressed to responsible authorities and now, waiting for a solution.
Decomposition of the course into subcomponents and into low level of its components worked well. It provided
many reasons for various issues, and found to be useful way to analyse issues of ME. The main findings indicate
that many factors, which contribute to the issues, are more related to teaching materials and policy makers than
students. The systems worldview of holistic philosophy seem to be more accepted than the Newtonian worldview
of reductionism in textbooks of MEDco as it is the same on the most of the ME course textbooks. This should be
changed as soon as possible to reduce the unnecessary complexity of engineering education. Therefore, reasonable
reduction on the text, considerable simplification of expressions and removing of redundant approaches appear to
be essential for the MEDco the textbooks. Additionally, tidying of the textbooks may be required by considering
reliability issues, ease of use, and contradictions. Furthermore, uniform structural integrity of all courses in ME
degree should have to be fully established.
The above in turn may possibly eliminate;
 Cognitive issues
 Drop-outs and attritions
 Ruined confidence of students.

17
Micro studies, which provided the reasons for the issues in a particular course, are the precursor of macro ones
for university degrees. This is because the design of other mechanical elements and other courses of ME may
suffer from the similar issues.
The above evidences indicate that engineering students’ reduced science and mathematics competencies are
not to be fully blamed for the reduced quality of ME graduates.
If the method is extended to other courses of ME, it may eliminate most of the issues and integrate courses for
student’s success in profession. Finally, as it is also stated by Li (2008), reform is inevitable in ME education in
order to reduce above issues and improve quality of graduates. In long term, it may reduce the perceived degree
of difficulty of ME education.
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