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Java, the Web, and Software Development

Edward YourdonComputer, Aug96

text 535-540

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The BIG Deal

“the big deal is the elimination of “fatware” and the growth of a global cottage industry associated with the creation of Java components.”

“The real paradigm shift, in my opinion, will be the replacement of purchased software packages with transaction-oriented rental of Java applets attached to web pages”

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Group Discussion Is Yourdon’s rental view correct?

Yourdon is not the only one with the rental view. Another author suggested that if we enforce per-use charges, many developers will package small algorithms for market. Developers will re-use these in other code and pass the use charges on to the original developers

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Managing Domain-Specific, Product-Line Development

Macala, etalIEEE Software May 96

text pp548-557

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Product-line Development

“seeks to achieve reuse across a domain, or family, of systems”

“separates the software-development process into two separate life cycles: domain engineering, which aims to create reusable assets, and application engineering, which fields systems using those assets”

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RSP

Software Productivity Consortium’s Reuse-Driven Software Process

– “A method for defining, analyzing, specifying, and implementing a domain that encompasses a software product line”

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Domain Engineering

“grows the domain through a series of iterations in response to the needs of the application-engineering organizations”

Significant investment

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Lessons Learned (1)

1. Don’t skip analysis and planning 2. Don’t compromise your skill

requirements 3. Adding staff during iterations slows

progress 4. The lack of standard development

practices inhibits progress

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Lessons Learned (2)

5. There is no adequate substitute for experience when learning RSP (ojt)

6. Existing procurement models do not readily support product-line development

7. Existing software organizational structures conflict with a product-line focus

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Class Discussion

Is product-line development useful as a general approach?

What economic/environmental factors would favor product-line development?

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Experiences of a Software Reuse Project

IsodaJ. of Systems and Software, Sep95

text pp558-573

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Re-use Ratio

Reused / (new + reused + modified)– Based on size of modules

New = newly developed Reused = taken from reuse library Modified = modified units of base program No change = unmodified units of base

program

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Average reuse ratio

Initially 3%

16% in 4th year (below goal)

Average size of reused module increased to 600 loc

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Library usage

Reuse frequency – ratio of yearly sum of reuse frequencies to number of modules stored

1st – 0.18 to 4th - 0.28 Active module ratio – ratio of number used

at least once to number of modules stored Stayed at 0.18

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Fig 15 p568

Total costs of conventional and reuse-based development

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Class Discussion

What was different between this reuse and product-line development?

What economic/environmental factors encourage reuse?