object-Oriented Software Engineering Practical Software development using uml and Java Chapter 1: Software and Software Engineering www.oseng.com
Object-Oriented Software Engineering Practical Software Development using UML and Java Chapter 1: Software and Software Engineering
1.1 The nature of software Software is intangible Hard to understand development effort Software is easy to reproduce Cost is in its development in other engineering products manufacturing is the costly stage The industry is labor-intensive Hard to automate www.oseng.com O Lethbridge/Laganiere 2001 Chapter 1: Software and Software Engineering
© Lethbridge/Laganière 2001 Chapter 1: Software and Software Engineering 2 1.1 The Nature of Software... Software is intangible • Hard to understand development effort Software is easy to reproduce • Cost is in its development —in other engineering products, manufacturing is the costly stage The industry is labor-intensive • Hard to automate
The nature of software Untrained people can hack something together Quality problems are hard to notice Software is easy to modify People make changes without fully understanding it Software does not wear out It deteriorates by having its design changed -erroneously, or -in ways that were not anticipated, thus making it complex www.oseng.com O Lethbridge/Laganiere 2001 Chapter 1: Software and Software Engineering
© Lethbridge/Laganière 2001 Chapter 1: Software and Software Engineering 3 The Nature of Software ... Untrained people can hack something together • Quality problems are hard to notice Software is easy to modify • People make changes without fully understanding it Software does not ‘wear out’ • It deteriorates by having its design changed: —erroneously, or —in ways that were not anticipated, thus making it complex
The nature of software Conclusions Much software has poor design and is getting worse Demand for software is high and rising We are in a perpetual software crisis We have to learn to engineer software www.oseng.com O Lethbridge/Laganiere 2001 Chapter 1: Software and Software Engineering 4
© Lethbridge/Laganière 2001 Chapter 1: Software and Software Engineering 4 The Nature of Software Conclusions • Much software has poor design and is getting worse • Demand for software is high and rising • We are in a perpetual ‘software crisis’ • We have to learn to ‘engineer’ software
Types of Software Custom For a specific customer Generic Sold on open market Often called -COTS( Commercial Off The Shelf Shrink-wrapped Embedded Built into hardware Hard to change www.oseng.com O Lethbridge/Laganiere 2001 Chapter 1: Software and Software Engineering
© Lethbridge/Laganière 2001 Chapter 1: Software and Software Engineering 5 Types of Software... Custom • For a specific customer Generic • Sold on open market • Often called —COTS (Commercial Off The Shelf) —Shrink-wrapped Embedded • Built into hardware • Hard to change