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Chapter 2 Systems Development and The Software Crisis

Chapter 2 Systems Development and The Software Crisis. Chapter 2 Systems Dev. & the S/W Crisis.  Brief History  Need for a New Approach  Costs and Benefits of Objects.  Brief History. 1950s and 1960s, Systems Analysis was unstructured, unorganized It was not done well.

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Chapter 2 Systems Development and The Software Crisis

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  1. Chapter 2Systems Development and The Software Crisis

  2. Chapter 2 Systems Dev. & the S/W Crisis Brief History Need for a New Approach Costs and Benefits of Objects

  3. Brief History • 1950s and 1960s, Systems Analysis was unstructured, unorganized • It was not done well. • Over the last 30 years there have been many improvements • But software still has just as many bugs! • But back then a large project was a few thousand lines of code • Nowadays largemeans several millionlines of code.

  4. Brief History Maintenance changes have always been a problem.

  5. Brief History • Backlogs • At any time there has been about a 5-year backlog • Plus there has also been a 5-year invisiblebacklog. • This has had two effects: • A move to end-user computing • A constant search for better ways to develop software systems.

  6. Brief History • Reliability • What caused all the maintenance and backlogs? • Poor initial design led to problems of • Flexibility, the ability of a system to handle unforeseen events or transactions • Resilience, the ability to handle changes during maintenance without other problems happening with every little change.

  7. Need for a New Approach to Systems Development • Many business managers do not realize how complex software development can be • Many use amateurs and hackers • Others hire out-of-date “professionals” • There are good ways and bad ways to do it • Good consultants are expensive • Because that’s what they are worth in ROI (Return on Investment)

  8. “The Dead COBOL Programmers’ Society.”

  9. Costs and Benefits of Objects Benefits of Objects: • System Stability • Maintainability • Reusable software components • Reality-based systems • Data accessibility • User involvement and ownership

  10. Costs and Benefits of Objects Costs of Objects: • Installed software base • COBOL • Legacy Systems: Out-of-date systems that already exist and must continue to exist for the foreseeable future. • Retraining • Not just a new language, but • A whole new way of thinking • Need a carefully-planned conversion • See Chapter 15, “Moving to O-O Techniques”

  11. End of Chapter 2

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