EENG 1920 Chapter 1

The Engineering Design Process

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Chapter Objectives

• By the end of this chapter, you should:– Understand what is meant by engineering design.– Understand the phases of the engineering design process.– Be familiar with the attributes of successful engineers.– Understand the objectives of this course

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Engineering Design

• The process of devising a system, component, or process to meet desired needs.

• It is a decision-making process (often iterative), in which the basic sciences, mathematics, and engineering sciences are applied to convert resources optimally to meet a stated objective.

• Among the fundamental elements of the design process are the establishment of objectives and criteria, synthesis, analysis, construction, testing, and evaluation.

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General Types of Design Processes

• Prescriptive– Prescribe an exact sequence of steps and decisions for

realizing a design.– Often algorithmic in nature– Expressed on flow charts with decision logic

• Descriptive– Describes general steps needed to achieve a design– Does not explicitly layout steps to achieve a design– Less formal than prescriptive process

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A Prescriptive Process

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Identify Problem& Needs

DetermineRequirements

Dorequirementssatisfy needs?

Yes

No

A Descriptive Process(Elements of the Design Process)

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ProblemIdentification

Research

RequirementsSpecification

ConceptGeneration

Prototypeand

Construct

SystemIntegration

SystemTest

Deliveryand

Acceptance

Maintenanceand

Upgrade

Design

Phases of the Design Process• Problem Identification• Research Phase• Requirements Specification• Concept Generation• Design Phase• Prototyping and Construction Phase• System Integration• System Test• Maintenance Phase

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Problem Identification• First phase

– Correctly Identify the problem or– Correctly Identify the customer’s needs

• Failure to correctly identify needs results in– Negative ramifications for entire project– Abandonment of the project– Costly redesigns

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Cost toimplementchanges

Project lifetime

Research Phase

• Research team conducts research on– Basic engineering and scientific principles– Related technologies– Existing solutions

• Become an expert on the problem– Do not reinvent the wheel– Develop new and innovative solutions

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Requirements Specification• Mission statement that guides the entire project• Articulates what the system must do to be:

– successful– accepted by the customer

• Focuses on what the system must do– Engineers tend to focus on solutions and propose

early implementation of solutions – Most Engineering education focuses on solving

problems instead of specifying them

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Concept Generation• Many possible solutions to the problem• Develop the best one that satisfies requirements

Design Phase• Team develops a technical solution• Produces a detail system design

– Describes all major systems and subsystems– Depends upon the particular technology being used

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Prototyping and Construction Phase

• Elements of The prototype system are constructed. – The objective of building a prototype system is to model

some aspect of the system.– Prototype model may not work: Testing is needed.

System Integration• All subsystems are combined to produce a complete

production model system.– Challenging and time-consuming– Teams must work together– Production model may not work: Testing is needed.

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System Integration

• All subsystems are combined to produce a complete system.– Challenging and time-consuming– Teams must work together

• Production model OT&E– Installed on-site: system delivery– Perform operational tests– Evaluate test results

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System Test

• Prototype operation testing and evaluation (OT&E)– Demonstrate the prototype meets requirements– Prototype may be discarded or modified

• Production model OT&E– Tested in-house first– Installed on-site: system delivery– Perform operational tests– Evaluate test results

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Maintenance Phase

• Design problems are corrected.• Maintenance is performed.• System up-grades are made.

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Successful Engineers

• Aware of the world: alert to market opportunities• Solidly grounded: Thoroughly trained• Technically broad: Conversant in several disciplines • Effective in group operations:

– Willing to seek and use expert advice– Cooperative with group members– Effective in written and oral communication

• Versatile: innovative in the development of products and services• Customer oriented: satisfied customers guarantees business

success

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Technical Design Tools

• LABVIEW– Laboratory Virtual Instrumentation Engineering Workbench

(LABVIEW) is a graphical programming environment based on the concept of data flow programming.

– Widely adopted by industry, academia, and research laboratories around the world as the standard for data acquisition and instrument control.

• MATLAB– Matrix Laboratory (MATLAB) is a numerical computational software for

engineering and scientific calculations.– Primarily a tool for matrix calculations– Has a rich set of plotting capabilities– Has a large collection of toolboxes

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Technical Design Tools

• VHDL– VHSIC Hardware Descriptive Language (VHDL) is an industry-

standard language for PLD design.• VHSIC : Very High Speed integrated Circuit• PLD: Programmable Logic Device• Programmed in Xilinx software program

• PSPICE – Simulation Program with Integrated Circuit Emphasis (SPICE) is

a simulation program that enables you to design a circuit and then simulate the design on a computer.

– PSPICE is a SPICE program produced by the OrCAD company.

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VLSI System Design Process• VLSI – Very Large Scale Integration

– System specification is used to develop the system architecture.

– System architecture is composed of major functional unit– Functional units designed at the

• Gate logic level• Circuit level• Circuit elements laid out on a silicon chip

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SpecificationSystem

ArchitectureLogic Design Circuit Design Layout

Is this prescriptive or descriptive?

Embedded System Design Process• Embedded systems are combined

hardware/software embedded in a large system to perform dedicate application-specific operations.

• Employed in automobiles, DVD players, and digital cameras

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Software Design Application Operating System Compiler

Hardware Design Architecture Synthesis Compiler

RequirementsAnalysis

Specifications

SystemArchitecture

Interface Design Software Drivers Hardware Drivers

Integrationand Test

Descriptive or Prescriptive?

Waterfall Software Development

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RequirementsAnalysis

SpecificationDevelopment

Software Design

Test andVerification

Maintenance

Descriptive or Prescriptive?

While the waterfall methodology offers an orderly structure for software development, demands for reduced time-to-market make its series steps inappropriate.

Spiral Methodology

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The spiral methodology reflects the relationship of tasks with rapid prototyping, increased parallelism, and concurrency in design and build activities. The spiral method should still be planned methodically, with tasks and deliverables identified for each step in the spiral.

Success In Executing The Engineering Design Process

• Understanding of the design process• Able to use strong technical design tools• Professional skills

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Course Objectives

• Understand a project’s life cycle. • Gain proficiency with LABVIEW,

MATLAB, VHDL and PSpice software.• Know project report procedures.• Appreciate oral presentations

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Chapter 1 Homework

1. Define Engineering Design.2. Name the phases of the design process.3. Describe the Technical Design Tools described

in this chapter.

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