The lesson outcomes are to identify the definitions of ‘design’ and describe the steps in the design process.

1. DESIGNPROCESS
Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial
& Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)
Department of Agricultural Engineering and Soil Science
Rajarata University of Sri Lanka
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Design Philosophy

2. LESSON OUTCOMES
 Identify the definitions of ‘design’
 Describe the steps in the design process
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

3. DESIGN TECHNIQUES
Everything should be made as simple as possible, but not
simpler.
Albert Einstein
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

4. DESIGN TECHNIQUES
All progress, all success springs from thinking.
Thomas Edison
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5. DESIGN
• Engineering Design is a broad subject, which has different opinion on;
• How to design?
• What distinguish good design from bad design?
• Whether the design is more art than science?
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

6. ENGINEERING DESIGN-POSITION
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

7. DESIGN
• Harder the design problem, leads to diversity of solutions and usually a
better design
• Self review and peer review of the design is important
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

8. DEFINITION OF DESIGN
• Accreditation Board for Engineering and Technology (ABET)
“Engineering design is the process of devising a system, component, or
process to meet desired needs.”
• It is a decision-making process (often iterative), in which the engineering
sciences and mathematics are applied to convert resources optimally to meet a
stated objective.
• The fundamental elements of the design process are the establishment of
objectives and criteria, synthesis, analysis, construction, testing and evaluation.
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

9. MECHANICAL DESIGN
• Mechanical Design
“The design of components and systems of a mechanical nature—
machines, products, structures, devices, and instruments.”
• For the most part mechanical design uses mathematics, material, and the
engineering-mechanics sciences.
• Additionally, it uses engineering graphics and the ability to communicate
verbally to clearly express your ideas.
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

10. MECHANICAL ENGINEERING DESIGN
• Includes all mechanical design, but it is a broader study because it
includes all the disciplines of mechanical engineering, such as the
thermal fluids and heat transfer sciences too.
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

11. THE PHILOSOPHY OF ENGINEERING DESIGN
• A set of consistent principles and their logical derivations
• An operational discipline which results in action
• A critical feedback apparatus which measures the advantages, reveals
the shortcomings, and describes the direction of improvement
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

12. ELEMENTS OF ENGINEERING DESIGN PHILOSOPHY
General principles
and inputs concerning
a design
Discipline
of design
Evaluating
scheme
Design
Critical
feedback loop
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

13. TYPES OF DESIGN
• Adaptive design
Based on existing design, for example, standard products or systems adopted for a new application
Ex: Conveyor belts, control system of machines
• Developmental design
Start with an existing design but finally a modified design is obtained
Ex: A new model of a tractor
• New design
Entirely new one but based on existing scientific principles
No scientific invention is involved but requires creative thinking to solve a problem
Ex: designing a fully automated ploughing tractor for a small field
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

14. TYPES OF DESIGN BASED ON METHODS
• Rational design
Based on determining the stresses and strains of components and thereby deciding their
dimensions. Depends on mathematical formulas and principles of mechanics
• Empirical design
Based on empirical formulae which in turn is based on experience and experiments
• Industrial design
Based on industrial considerations and norms viz. market survey, external look, production facilities,
low cost, use of existing standard products
It is the ornamental or aesthetic aspect of an article. It does not have any functional character. An industrial
design may consist of three dimensional features, such as the shape of an article, or two dimensional
features, such as patterns, lines or color (NIPO and WIPO)
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

16. Capacity of upper part
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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)

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Dr. (Ms.) Jayaruwani Fernando, Ph.D. (Ag. & Biosystems Engineering), M.S. (Industrial and Ag. Technology), M.Phil. (Ag. & Biosystems Engineering), B.Sc. (Agriculture)