Mick F Ranky can be contacted at CIMware by email: cimware@cimwareukandusa.com

Paul G. Ranky can be contacted at ADAM or at NJIT, USA, Department of Industrial and Manufacturing Engineering, New Jersey Institute of Technology, NJ 07102, USA, Email: ranky@admin.njit.edu

• Abstract
• Keywords
• An introduction to our educational objectives...
• The ABET professional component requirements...
• Introduction to standard pneumatic positioning solutions...
• An overview of servo pneumatic components & systems...
• The assembly of a servo system: Testing the assembly...
• The importance of detail at component level
• Summary and conclusions
• Acknowledgements
• References

Abstract

Go to top

Servo pneumatics retains the advantages of standard pneumatics and adds the opportunity for closed loop controlled, programmable positioning to within fractions of a millimeter in systems in which positions can be approached rapidly and without overshoot, stability under variable loads and conditions, and adaptive control for optimized positioning.

Our challenge was to create an interactive multimedia program that could communicate exciting technical material to interested parties, including students and academia, professional design, industrial and manufacturing systems engineers, marketing and sales engineers and managers in a non-linear, enjoyable fashion. Our approach was that of interactive multimedia on CD-ROM, allowing the integration of text, color images, videos and animation for the purpose of following an engineering problem solving approach, both when modeling, as well as when illustrating real-world solutions with interactive digital videos.

Furthermore, this article introduces Outcome - Driven Assessment principles (as defined by ABET - The American Accreditation Board of Engineering Education), as the key to our educational multimedia design objectives. It illustrates open loop controlled pneumatic and closed loop-controlled servo pneumatic positioning systems, their components, their programming and some of their applications.

Keywords

Engineering education, Interactive multimedia education, Pneumatic positioning and control, Servo pneumatics control, Programming and applications of servo pneumatic systems, Outcome - Driven Assessment, ABET (American Accreditation Board of Engineering and Technology)

An introduction to our educational objectives with a strong emphasis on Outcome Driven Assessment

Go to top

In terms of our educational design and development goals we have followed the principles of Outcome - Driven Assessment and created an interactive educational package that is compatible with many of the requirements set by The American Accreditation Board of Engineering and Technology (ABET).

In order to gain an insight into what these Outcome - Driven Assessment Principles are, and how we have followed them with our interactive engineering multimedia design let us first outline the philosophy and the requirements that relate to our educational multimedia development, and then give a list (with examples) of the way our interactive multimedia design supports these educational principles and requirements ([1] to [4]).

As stated by ABET, The Accreditation Board for Engineering and Technology is recognized in the United States as the sole agency responsible for accreditation of educational programs leading to degrees in engineering. The first statement of the Engineers' Council for Professional Development (ECPD, now ABET) relating to accreditation of engineering educational programs was proposed by the Committee on Engineering Schools and approved by the Council in 1933.

The original statement, with subsequent amendments, was the basis for accreditation until 2000. (Kindly note, that he statement partially presented here is required of engineering programs beginning in 2001 in the USA).

Similarly to the various European Engineering Accreditation Systems, the USA/ ABET accreditation process is a voluntary system of accreditation that

• Assures that graduates of an accredited program are prepared adequately to enter and continue the practice of engineering
• Stimulates the improvement of engineering education
• Encourages new and innovative approaches to engineering education, and
• Identifies these engineering education programs to the public. 

According to ABET, engineering programs must demonstrate that their graduates have

• an ability to apply knowledge of mathematics, science, and engineering
• an ability to design and conduct experiments, as well as to analyze and interpret data
• an ability to design a system, component, or process to meet desired needs
• an ability to function in multi-disciplinary teams
• an ability to identify, formulate, and solve engineering problems
• an understanding of professional and ethical responsibility
• an ability to communicate effectively
• the broad education necessary to understand the impact of engineering solutions in a global and societal context
• a recognition of the need for, and an ability to engage in life-long learning
• a knowledge of contemporary issues
• an ability to use the techniques, skills, and modern engineering tools necessary for engineering practice.

Furthermore, ABET clearly states, that each engineering program must have an assessment process with documented results, in which evidence must be given that the results are applied to the further development and improvement of the program.

The assessment process must demonstrate that the outcomes important to the mission of the institution and the objectives of the program, including those listed above, are being measured.

The ABET Professional Component requirements and their satisfaction by means of interactive multimedia design

Go to top

In terms of important criterion, that had a major effect on our engineering multimedia design, let us discuss in more detail what ABET refers to as the "Professional Component". The Professional Component requirements specify subject areas appropriate to engineering but do not prescribe specific courses.

Amongst others, it states, that the engineering faculty must assure that the program curriculum devotes adequate attention and time to each component, consistent with the objectives of the program and institution. Students must be prepared for engineering practice through the curriculum culminating in a major design experience based on the knowledge and skills acquired in earlier coursework and incorporating engineering standards and realistic constraints that include most of the following considerations: economic; environmental; sustainability; manufacturability; ethical; health and safety; social; and political.

To summarize, according to ABET, the professional component must include the following:

• One year of a combination of college level mathematics and basic sciences (some with experimental experience) appropriate to the discipline
• One and one-half years of engineering topics, to include engineering sciences and engineering design appropriate to the student's field of study
• A general education component that complements the technical content of the curriculum and is consistent with the program and institution objectives.

In terms of facilities, ABET states and implies, that classrooms, laboratories, and associated equipment must be adequate to accomplish the program objectives and provide an atmosphere conducive to learning.

Appropriate facilities must be available to foster faculty-student interaction and to create a climate that encourages professional development and professional activities. Programs must provide opportunities for students to learn the use of modern engineering tools. Computing and information infrastructures (including multimedia and the Internet) must be in place to support the scholarly activities of the students and faculty and the educational objectives of the institution.

Following the ABET requirements and the principles of Outcome - Driven Assessment in our educational multimedia design, the issue was to be able to structure and story-board the several hundred photos, over 50 minutes of interactive, digital videos, animation and text on the CD-ROM in such a way that the final educational package satisfied the following criteria:

• Engineering science principles should be introduced and discussed in a simple, easily graspable way using modeling, animation as well as real-world systems and examples.
• The program could be viewed both in a sequential way (i.e. following our programmed path, from the introduction to the end), as well as in a non-linear (or in other words direct access fashion) following a "multimedia talking book" format, using literally any multimedia PC or Mac.
• Data/ information could be found quickly and easily even for any non-linear navigator either by just clicking with the mouse and interrogating various screens, or by going through the index and navigating back-and- forth between the integrated material and the index entries.
• The CD-ROM should employ fast object linking methods, both when running it as an integrated program, as well as when accessing individual objects, such as individual images, videos, or animation.

As examples, consider that in our CD-ROM we have included an explanation to the way pneumatic components can be used for building various engineering systems, the way such systems are integrated by means of open-loop and/ or closed loop control by means of PLCs, we have covered some of the most important aspects of their programming, the way multi-disciplinary teams should assess such system developments covering the economic as well as technical aspects, the way such components and systems are applied in industry, touching on the engineering problem solving and design experience, and others, such as the assembly, commissioning and maintenance aspects of such systems ([5] to [8]).

To summarize the above in a more systematic way, we have attempted to fulfill the following educational goals and requirements for our learners (i.e. for "the student"):

• Have the choice and the freedom to learn
• Be supported by the multimedia based learning materials and technology and that
• Offer the best use of learning objectives, in a user-friendly style, environment and flexibility (time, place and pace)
• Enable tutor marked assignments, and/or self-assessment
• Provide an education process and experience that, as far as possible, is designed and delivered to satisfy individual needs while being controlled by the individuals themselves

In this context, the benefits of using interactive multimedia to the learners/ users include the following ([9] and [10]):

• Multimedia is inexpensive. Literally all new PCs and Macs are powerful multimedia machines with, CD-ROM, video, sound and networking capabilities (including the Internet)
• Students can study at their own time, place and pace
• In the case of CD-ROMs learning is conducted in a non-linear (or in other words direct access) fashion, compared to the traditional linear mode of delivery. This enables learners to learn by exploring versus learn as told!
• The entire learning process becomes more student versus lecture centered
• Multimedia is easy to use and is interactive. Most programs are "hot-spot" driven, enabling the user to move the cursor on the screen with the mouse and interrogate new areas of information by clicking on the selected object
• The "explore & act" nature of the learning process satisfies the young generation's appetite for learning at their own pace and sequence, under their own control
• Students can have as many goes at solving a problem, or exploring an idea, taking as much time as desired or is available
• Mistakes made can be corrected without penalties
• Multimedia tools, or a subset of such technology and a variety of media is available during the learning process
• Self-assessment is possible. This means that students become more self-critical, they participate directly in their own learning process, it eliminates "hidden curriculum" and self-assessment questions give instant assessment and response
• Tutorial support is available if required. In the case of an up-to-date learning program on-line help is available on the Internet. This means, that the relatively fast CD-ROM technology (typically 12x =1800 to 24x = 3600 Kbytes/sec transfer rates) offers the bulk of the material using the CD-ROM as a mass storage media (650 Mbytes, max.) and the Internet (a relatively slow technology with relatively slow transfer rates; typically 1.8 Kbytes/sec (14.4 modem) to 16 Kbytes/sec (ISDN)) supports real-time learning needs, or very frequently changing information
• When using multimedia learning tools, students are better motivated, because they can learn by exploring versus being told
• With multimedia the entire education process is more suited to satisfy individual needs and small-team oriented activities because it can both satisfy synchronous as well as asynchronous collaboration between team members, even if the teams are apart physically
• Interactive multimedia supports the concept of "telepresence", meaning, that despite the fact that the learner(s) and the tutor(s) are physically apart, they are electronically linked by sharing the same material they are exploring on CD-ROMs and the Internet. Furthermore, this means, that the "telepresence"-type of collaboration supports both performance as well as learning
• Groups (i.e. small teams) can solve more interesting and more complex problems than can an individual working alone. This is most effective if all members of the team can "speak the same language" - meaning that they are brought up to the same level of understanding of the basics related to the particular area. Interactive Multimedia can do an excellent job in supporting this process effectively and at a low cost

Last but not least, there is an other very important issue: since failure is not exposed in Open/ Distance Learning situations, fear is not part of the learning and testing process. Multimedia supports student performance.

Student motivation can quickly diminish if students aren't confident that they can solve authentic problems. The learning process, for all parties involved, is the most successful if students have the opportunity to succeed ([11] to [16]).

Following the above outlined principles, according to our experiences in classrooms, laboratories, and associated facilities interactive multimedia fosters faculty-student interaction and creates a climate that encourages professional development and professional activities.

Such educational programs, preferably coupled with real-life experiments, provide opportunities for students to learn the use of modern engineering tools, including computing and information infrastructures.

Introduction to standard pneumatic positioning solutions and the instability of open loop pneumatic systems

Go to top

In order to introduce and discuss engineering science principles in a simple, easily graspable way using modeling, animation as well as real-world systems and examples, we have chosen open-loop as well as closed loop controlled pneumatics.

In industry, pneumatics is selected for automation and handling tasks as a preferred medium because it is relatively inexpensive, simple to install and maintain, offers robust design and operation, is available in a wide range of standard sizes and design alternatives and offers high operating speeds and cycle rates.

Positioning with standard pneumatics is possible but with limitations. One of the limitations of compressed air as a positioning medium is the difficulty of obtaining movement other than those of a binary type: In/ Out, Retracted/ Extended, Raised/ Lowered, etc.

Movements are usually obtained from a double acting pneumatic cylinder actuated by a five port, two position (5/2) valve. Stroke movements are made along the full length of the cylinder.

Furthermore, open loop pneumatic systems are not stable, because the stop position depends upon external variables, such as the speed of the cylinder, the mass being moved, the external forces acting on the system, the system pressure, the leakage across the piston, the valves, or fittings and to a lesser extent, the repeatability of response within the PLC (Programmable Logic Controller) and the repeatability of the response of the valve.

Servo pneumatics retains the advantages of standard pneumatics and adds the opportunity for closed loop controlled, programmable positioning to within fractions of a millimeter in systems in which positions can be approached rapidly and without overshoot, stability under variable loads and conditions, and adaptive control for optimized positioning.

In open loop pneumatic systems the stop position depends upon external variables, such as the speed of the cylinder, the mass being moved, the external forces acting on the system, the system pressure, the leakage across the piston, valves, or fittings and to a lesser extent, the repeatability of response within the PLC and the repeatability of the response of the valve.

Several of these factors vary in most industrial applications therefore in most cases the stopped mid stroke position of a pneumatic actuator is not accurate, repeatable or stable. As an example consider a vertically mounted cylinder in a stop position, with and without an external load. The air in the cylinder is compressible, therefore the load force causes the lower chamber in the cylinder to be further compressed, while the upper chamber expands.

In order to explain the simplest possible open loop controlled pneumatic system we have created an interactive animation sequence on digital video. The animation shows the control sequence using a standard configuration.

The fact, that the animation is interactive, meaning it can be controlled frame-by-frame, standard speed play, and fast forward (and all above in reverse) functions, enables the learner, or user to analyze the most important transition points in the entire sequence. This animated model, coupled with a real-world interactive digital video example provides the engineering experience on how such systems work.

An overview of servo pneumatic components & systems with particular interest towards comparing it with standard, open loop controlled pneumatic positioning solutions

Go to top

Servopneumatics is an electro-pneumatic solution to accurate and fast positioning. It is an alternative to "electric only" positioning, since it eliminates electric motors with their relatively expensive maintenance procedures and power supplies, as well as offers the often crucial "clean air, zero sparks" solution to positioning.

Note, that in the digital, interactive video put on this screen, the economic aspects of this new technology are discussed. From an educational point of view, this was very important to illustrate that a professional designer will consider and then chose a new technological solution on the basis of not just technical, but also other merits, including cost.

Servo pneumatic actuators use proportional pneumatic valves and rely on the integration of electronic, closed- loop controlled servo techniques. The heart of the system is the axis controller, that continuously processes motion information in the form of positioning control signals, as well as fulfills diagnostic and other functions.

The positioning control signals are sent to the servopneumatic valve, where they are converted to a flow output, proportional to the input signal. This output is fed to the pneumatic actuator, which moves to the pre-programmed (i.e. "to be") stop position.

The actual position (i.e. "as is") is read by the position transducer (a sensor), and a signal is fed to the controller for comparison with the programmed position. If there is a difference (i.e. error) in the actual (i.e. "as is") position, the axis controller sends a correction signal to the valve and the movement is executed - in a similar fashion to a closed loop a numerically controlled, CNC system.

There are four main components within the FESTO Servo Pneumatic Positioning System. These being:

1. Actuator

2. Measuring device

3. Servo (Dynamic Control) valve

4. Controller

In order to provide a comprehensive overview to both the academic as well as the professional engineering community, in the CD-ROM, we classify and discuss the main servo-pneumatic components as follows:

• Types of standard actuators for use with servo pneumatics
  • Standard
  • Rodless cylinders
• Types of measuring devices
  • Analogue potentiometer
  • Digital Temposonic
  • Integrated Temposonic
• Valves
  • Servo (Dynamic Control) valve
  • Function & characteristics
• Controllers & Interfaces
• Selection & sizing of components for optimum system performance
• Advantages of Servo Pneumatic Control

Let us give some examples of the above, with particular interest towards the educational challenges on how we have communicated the information to the learners/ users of our system. Note, that in order to illustrate our educational and multimedia design solutions, we are discussing this topic in the Figures attached to this paper. These are actual screen shots taken from the CD-ROM itself. (Note, that the original screens are in full color, and that the images are digitized in thousands of colors, offering clear colors and edges. In this Internet-based article we have reduced the resolution and the number of colours to support typical transfer rates over the net).

The assembly of a servo system: Testing the assembly - a preparation for recognizing the way systems can be integrated

Go to top

When assembling servopneumatic systems the engineer/ technician must follow strict technical instructions and guidelines - as listed below.

In order to explain these instructions in detail as well as to make sure, that all important principles and techniques are well understood, we have included several interactive digital videos into the CD-ROM that can be studied in detail, played even frame-by frame - if necessary. (One should note, that such visually attractive problems as the assembly of complex systems lends itself to interactive multimedia education).

• The critical technical instructions we had to communicate in our educational program are as follows:
• All mechanical assemblies are complete and checked to ensure free running throughout their stroke length
• Electrical connections can then be completed
• The wiring connections must be made to the sensor, the valve and the power supply
• A battery to back-up RAM program memory must be attached to the controller and connected to the pin strips
• Certain inputs are also required to allow the controller to pass beyond the initialization stage. These depend upon the selected mode of operation required. Once all connections have been made it is possible to check the controller status, the valve connections / operation, and the sensor connections / operation.
• Pneumatic supply pressure should be slowly "bled" in to the system after ensuring that all areas are safe, that there are no loose components, all parts have unrestricted movement, no personnel can be hurt and machinery or parts damaged
• When using mechanically coupled rodless cylinders the sealing strip should be orientated downwards to prevent the ingress of dust or liquids
• Standard cylinders should be guided to ensure relatively constant friction throughout their stroke length
• Ensure that the measuring device is correctly set or protected from bearing the force of the actuator in the event of an accident
• External shock absorbers and end of stroke stops are recommended where a sensor has been selected shorter then the cylinder stroke length.
  • Fit the servo valve as close as possible to the actuator
  • The air supply should be dry and unlubricated
• A maximum size 5-micron filter should be fitted in the air supply line
• Use a large bore tubing run to the servo valve - with a minimum bore greater or equal to the nominal bore of the servo valve
• Straight fittings and matched pipe runs enhance system performance
• Where the air supply fluctuates an in-line air reservoir smoothes out variations and again enhances system performance
• Consideration should be given to the required actions under emergency stop or air dump / failure conditions
• Standard circuits are available in the event of an emergency stop to:
  • De-pressurize the cylinder
  • Clamp the piston by trapping the air on both sides
  • Pressurize either side of the piston thus causing the cylinder to go to a 'safe' position - left, right, up or down.
• The servo valve has a very high flow and switching rates. This causes it to be noisy unless silencers are used. It is recommended that a re-classifier or exhaust air reservoir manifold is used. These allow the exhausting air a very free flow path at the same time as significantly dropping the exhaust air velocity.

The importance of detail at component level

Go to top

In order to increase the awarenes of our engineering students, and/or maintenance engineers of the importance of detail at component level, specifically regarding the electrical connection, we had to emphasize the following:

• If the cylinder body is mounted to the machine and the rod or carriage moves the valve port nearest solenoid head (port-2) connects to 'zero or home end' of cylinder. (The electrical connection of the measuring device is at the same end of cylinder)
• If the cylinder body moves and the rod or carriage is mounted to the machine frame the valve port furthest from the solenoid head (port-4) connects to 'zero or home end' of cylinder. (The electrical connection of the measuring device is at the same end of cylinder)
• Connecting cables can be cut to length before assembling to the screw in terminals. All connections should be checked to ensure good electrical continuity.
• Screened cables are required in control systems handling analogue signals. Therefore the servo valve cable and the potentiometer cable are screened. In noisy electrical environments it is particularly important that these are terminated on the spade connections provided at the rear of the axis controller to prevent interference.
• There is an impedance balancing device incorporated in the cable near the plug on the potentiometer system. This should not be tampered with, the cable should be reduced in length from the free end. 

In terms of following our educational design and development goals based on the principles of Outcome - Driven Assessment, in this section students have to face real-life problem solving situations and with the aid of multimedia, immediately get answers to illustrated problems ([17] to [21]).

Summary and conclusions

Go to top

In order to increase the ability to apply knowledge of mathematics, science, and engineering, to design and conduct experiments, as well as to analyze and interpret data, to design a system, component, or process to meet desired needs, to work in multi-disciplinary teams, to identify, formulate, and solve engineering problems, to understand the impact of engineering solutions in a global and societal context, and to use the techniques, skills, and modern engineering tools necessary for engineering practice we have developed the "Introduction to Servo Pneumatic Positioning" interactive multimedia program.

The combined results of various independent surveys conducted by the FESTO Forum members in the UK, the University of Abertay Dundee (Scotland), by the University of East London (England), and by NJIT (New Jersey Institute of Technology, USA) support the discussed benefits of multimedia and open learning in general.

Based on the responses, it is obvious that both students as well as academics have rated interactive multimedia to be on the top of the list of advanced learning tools, in comparison to traditional methods, such as wall charts, the black-board, the white board, overheads, and others.

Interactive multimedia is not against able faculty. On the contrary, it supports both students as well as the faculty that teaches a particular course.

As amongst others, ABET puts the importance of faculty the following way: the faculty is the heart of any educational program. The faculty must be of sufficient number and must have the competencies to cover all of the curricular areas of the program.

There must be sufficient faculty to accommodate adequate levels of student-faculty interaction, student advising and counseling, university service activities, professional development, and interactions with industrial and professional practitioners, as well as employers of students.

The faculty must have sufficient qualifications and must ensure the proper guidance of the program and its evaluation and development. The overall competence of the faculty may be judged by such factors as education, diversity of backgrounds, engineering experience, teaching experience, ability to communicate, enthusiasm for developing more effective programs, level of scholarship, participation in professional societies, and registration as Professional Engineers.

Educating others as well as ourselves is not a simple task. Since each of us is unique, it is necessary to find out more about us as well as about the "art and science" based methods, tools and technologies that relate to modern education. Open/ Distance Learning, Open/ Distance Access Flexible Learning, Distance Learning and Interactive Multimedia represent some of these methods, tools and technologies.

The world is moving away from rigid mass production systems, because industry has discovered that customers want different products that satisfy their individual or small group needs and not, as in the past necessarily those of the accountants, managers, designer, or manufacturer, therefore it is strategically important to renovate the pedagogical methods and environment in the educational institutions and stimulate the diffusion of good multimedia- based lifelong educational practices and solutions.

Acknowledgments

We hereby would like to express our thanks to FESTO, NSF (The National Science Foundation, USA), NJIT (New Jersey Institute of Technology, Newark, USA), ABET in the USA, The National Council for Educational Technology (NCET, UK), and The University of East London (UK) for their support in our multimedia developments.

References and Further Reading

Go to top

[1] Ranky, P. G, Ranky, M. F, Flaherty, M, Sands, S and Stratful, S: FESTO: Servo Pneumatic Positioning, an Interactive Multimedia CD-ROM with Internet support. Over 330 interactive screens, 650 Mbytes, CIMware & FESTO Automation joint development 1996, 1998, Interactive Multimedia Design & Programming by Ranky P G and Ranky M F. Internet Web site: www.cimwareukandusa.com

[2] Servo Pneumatic Positioning & Control Programming Manuals, by FESTO, 1996, 1998.

[3] ABET documents and Correspondence on Outcome - Driven Assessment, ABET 2000. The Accreditation Board of Engineering and Technology, USA, 1996.

[4] Ranky, P G: Interactive Multimedia for Engineering Education, European Journal of Engineering Education, Vol. 21, No. 3, 1996, p.273-293.

[5] Ranky, P G: An Introduction to Concurrent Engineering, an Interactive Multimedia CD-ROM with off-line and on-line Internet support, over 700 interactive screens following an Interactive Multimedia Talking Book format, CIMware 1996, Interactive Multimedia Design & Programming by Ranky, P G and Ranky, M F. Web site: www.cimwareukandusa.com

[6] Ranky, P G: An Introduction to Computer Networks, an Interactive Multimedia CD-ROM with off-line and on-line Internet support, over 700 interactive screens following an Interactive Multimedia Talking Book format, CIMware 1996, Interactive Multimedia Design & Programming by Ranky, P G and Ranky, M F. Web site: www.cimwareukandusa.com

[7] Ranky, P G: An Introduction to Flexible Manufacturing, Automation & Assembly, an Interactive Multimedia CD-ROM with off-line and on-line Internet support, over 700 interactive screens following an Interactive Multimedia Talking Book format, CIMware 1996, Interactive Multimedia Design & Programming by Ranky, P G and Ranky, M F. Web site: www.cimwareukandusa.com

[8] Ranky, P G: An Introduction to Total Quality (including ISO9001), an Interactive Multimedia CD-ROM with off-line and on-line Internet support, over 700 interactive screens following an Interactive Multimedia Talking Book format, CIMware 1997, Interactive Multimedia Design & Programming by Ranky, P G and Ranky, M F. Web site: www.cimwareukandusa.com

[9] Mager, Robert F.: Preparing Instructional Objectives, Kogan Page 1992

[10] Kayfetz, Janet L. and Stice, Randy L.: Academically speaking, Wadsworth, Boston, 1987

[11] Ranky, P G: Flexible manufacturing cells and systems in CIM, Book/CD combo, CIMware Ltd., 1990, 1998. 233 pp. and the CD-ROM with over 700 interactive screens

[12] Ranky P G: A methodology for supporting the product innovation process, USA/Japan International IEEE Conference on Factory Automation, Kobe, Japan, 1994. p. 234-239

[13] Norman, D.A and Spohner, J.C: Learner-centered Education, Communications of the ACM, April 1996/ Vol. 39. No.4, p.24-27.

[14] Shipley, T A and Armacost, R L: Systematic approach to new product development, Computers and Industrial Engineering, Sep 1993 25(9) 333-336p

[15] Bessant, J: The lessons of failure: learning to manage new manufacturing technology, Int Jnl Technology Management, 1993 8(3/4/5) 197-215p

[16] McCahon, C S, Rys, M J and Ward, K H: The Impact of Training Technique on the Difficulty of Quality Improvement Solving, Industrial Management & Data Systems, 1996 96(7) 24-31

[17] Senker, P: The Development and Implementation of National Vocational Qualifications: An Engineering Case Study, New Technology, Work & Employment, 1996 11(2) 83-95

[18] Forbes, D A and Spence, J: An Experiment in Assessment for a Large Group, Innovative Teaching in Engineering (Sheffield, Horwood), 1991.

[19] Mannison, M, Patton, W and Lemon, G: Interactive Teaching Goes to University: Keeping Studenyts Awake and Learning Alive, Higher Education Research and Development, 1994, Vol. 13, pp 35-47.

[20] Murray, R and Brightman, J R: Interactive Teaching, European Journal of Engineering Education, Vol. 21, No. 3, 1996, p.295-308.

[21] Somers, C B: Correlates of Engineering Freshman Academic Performance, European Journal of Engineering Education, Vol. 21, No. 3, 1996, p.317- 327.

Go to top