1 Product Lines 2: Escaping from the Oral Culture CSSE 371 Software Requirements and Specification Mark Ardis, Rose-Hulman Institute November 2, 2004

2 Outline Economics of product lines Implementing product lines Oral culture

3 Economics of Families Current Practice Number of Family Members Cumulative Cost Product Line Approach

4 Application Environment Product Line Engineering Model Domain Engineering Application Engineering Applications Feedback

5 Domain Engineering Application Environment Domain Analysis Domain Model Domain Implementation Analysis Document, Application Modeling Language Tools, Process

6 Application Engineering ApplicationApplication Environment Application Requirements

7 Application Environment Product Line Engineering Model Domain Engineering Application Engineering Applications Feedback

8 Eli Whitney Born December 8, 1765 Raised on a farm in rural Massachusetts Attended Yale College What did Whitney do in 1793?

9 The Cotton Gin Whitney invented the cotton gin in 1793 Southern planters refused to pay royalties on patent  The gin was easy to manufacture  Southern legislatures conspired against Whitney Whitney’s company was out of business by 1797 What did Whitney do in 1798?

10 Flintlock Components

11 Whitney’s Gamble on Automation Whitney offered to make 10,000 muskets in 2 years No other manufacturer had ever made more than a few hundred muskets Automation was needed to improve the efficiency of the locksmiths Whitney invented milling machines to produce interchangeable parts Demonstrated for Congress in 1802

12 Putnam Machine Company, 1875

13 Configuration Control Software that enables changes in switch configuration while the switch is operating  Ensures that requested configurations are valid and safe  Reconfigures  Example: Remove a Protocol Handler (PH) from service and replace it with a spare New switching technology requires new configuration controllers  New unit types for new functionality of lower COGS

14 Commonality Analysis of Configuration Control 1 staff-year effort over 6 months by 6 experts Produced a Commonality Analysis  Definitions: rational vocabulary  Commonalities: reusable algorithms  Variabilities: relationships between devices  Parameters of Variation: enumerated types Reviewed by organization

15 Building Technology for Configuration Control 2 staff-years effort over 12 months by 3 experts Languages -- capture generic algorithms and parameters Translators -- translate to executable code Interface to legacy system Graphical editor

16 SMALL-D Configuration Control Architecture SMALL-V SMALL-R Domain Engineering Environment Application Engineering Environment VFSM C Data Application RAD

17 Configuration Control Development Environment Application Engineer Domain Engineer Application Specific Configuration Control Reusable Assets Application Data Application Environment Interface RAD C Code Knowledge Base

18 RAD Tool

19 Reusable Assets Validations -- generic algorithms for every unit type Realizations -- generic algorithms for every unit type Relationships  data that is used to drive the generic algorithms  design information shared across development

20 Applications Project 1 (1994)  re-engineering project to demonstrate feasibility  replaced existing code and demonstrated in lab Project 2 (1996)  shadow project to demonstrate performance  duplicated work of another team and compared results Project 3 ( )  first real application  reworked domain analysis as work progressed Project 4 (1999)  production use

21 Interval Reduction on 5ESS Projects

22 Oral Culture

23 Problems of Oral Culture No History (Goody and Watt)  Story changes with each telling  Evolution breeds decay No abstraction (Luria)  Insistence on reasoning in terms of ground elements  Refusal to extend arguments to abstractions

24 From Orality to Literacy Write it down Identify abstractions Construct languages Create in the new languages

25 Power of Written Language Generic algorithms of Configuration Control  Translated to flowcharts and English for review  Executed in simulator for further review  Translated to VFSM for execution Commonality Analysis of Configuration Control  Starting point for DECC implementation  Starting point for 4 other designs