Java the Web and Software Development Edward Yourdon

Java, the Web, and Software Development Edward Yourdon Computer, Aug 96 text 535 -540 newmethod 18 a 1

The BIG Deal u “the big deal is the elimination of “fatware” and the growth of a global cottage industry associated with the creation of Java components. ” u “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” newmethod 18 a 2

Group Discussion u Is Yourdon’s rental view correct? u Yourdon is not the only one with the rental view. Another author suggested that if we enforce peruse 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 newmethod 18 a 3

Managing Domain-Specific, Product-Line Development Macala, etal IEEE Software May 96 text pp 548 -557 newmethod 18 a 4

Product-line Development u “seeks to achieve reuse across a domain, or family, of systems” u “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” newmethod 18 a 5

RSP u Software Productivity Consortium’s Reuse. Driven Software Process – “A method for defining, analyzing, specifying, and implementing a domain that encompasses a software product line” newmethod 18 a 6

Domain Engineering u “grows the domain through a series of iterations in response to the needs of the application-engineering organizations” u Significant investment newmethod 18 a 7

Lessons Learned (1) u 1. Don’t skip analysis and planning u 2. Don’t compromise your skill requirements u 3. Adding staff during iterations slows progress u 4. The lack of standard development practices inhibits progress newmethod 18 a 8

Lessons Learned (2) u 5. There is no adequate substitute for experience when learning RSP (ojt) u 6. Existing procurement models do not readily support product-line development u 7. Existing software organizational structures conflict with a product-line focus newmethod 18 a 9

Class Discussion u Is product-line development useful as a general approach? u What economic/environmental factors would favor product-line development? newmethod 18 a 10

Experiences of a Software Reuse Project Isoda J. of Systems and Software, Sep 95 text pp 558 -573 newmethod 18 a 11

Re-use Ratio u Reused / (new + reused + modified) – Based on size of modules u New = newly developed u Reused = taken from reuse library u Modified = modified units of base program u No change = unmodified units of base program newmethod 18 a 12

Average reuse ratio u Initially u 16% 3% in 4 th year (below goal) u Average size of reused module increased to 600 loc newmethod 18 a 13

Library usage u Reuse frequency – ratio of yearly sum of reuse frequencies to number of modules stored u 1 st – 0. 18 to 4 th - 0. 28 u Active module ratio – ratio of number used at least once to number of modules stored u Stayed at 0. 18 newmethod 18 a 14

Fig 15 p 568 u Total costs of conventional and reuse-based development newmethod 18 a 15

Class Discussion u What was different between this reuse and product-line development? u What economic/environmental factors encourage reuse? newmethod 18 a 16