Domain Engineering Arie van Deursen May 2001

2 Software Product Line  Group of products  sharing a common, managed set of features  to satisfy the needs of a selected market  Examples:  Telephone switches: 5ESS  Mortgage / insurance portals  Customer Relation Management  On line banking SAP, Baan, PeopleSoft

3 Object-Oriented Application Framework  Framework:  Set of cooperating classes embodying an abstract design  For solutions to a family of related problems  Supporting reuse beyond the class level.  Building an appliction consists of adding class specializations  Inverse control

4 Product Line Savings  Economies of scale  Savings from using technology to  produce a greater volume of a single output  with the same or less inputs  Economies of scope  Savings from using technology to  build a greater diversity of outputs  with the same or less inputs

5 Domain / Application Engineering  Domain engineering:  Systematic approach to construct reusable assets in a given problem domain  Application engineering:  Use the assets to build specialized software systems in the given domain.  ( Product / customer development )

6 What is a Domain?  Domain as the “real world”  Adopted in OO / AI community  Domain as a set of systems:  Systematic software reuse community  Domain criteria  Mature, stable, economically viable  Use legacy systems to understand domain.

7 Domain Engineering  Activity of  collecting, organizing and storing past experience in building (parts of) systems  in a particular domain  in the form of reusable assets  as well as providing means for resuing these assets (retrieve, adapt, assemble,...)  when building new systems

8 ODM: Organization Domain Modeling 1. Plan Domain:  Set objectives, analyze stakeholders  Scope domain: selection criteria  Define domain: boundary conditions, examples, counter examples, main features,  relations to other domains.

9 ODM (2) 2. Model Domain  Acquire domain information: experts, legacy systems, literature, prototyping,...  Describe domain: lexicon of terms, commonality & variability: feature diagrams  Refine domain: build overall domain, analyze trade offs, innovative feature combinations

10 ODM (3) 3. Engineer Asset Base  Scope: correlate features and customers, prioritize, select.  Architect: external and internal constraints, components, domain-specific languages, generators, framework,...  Implement: OO, code generation,...

11 Car Feature Diagram Car Engine Pulls trailer Transmission Manual Automatic ElectricGasoline Car body

12 Car Class Diagram ElectricEngineGasolineEngine ElectricCar [transmission] GasolineCar [transmission] ElectricGasolineCar [transmission] Car[transmission] CarBody Trailer O..1

13 Feature Diagrams  Node types:  Mandatory / Optional  Alternatives / Or-features  Diagram generates instances  Commonality: feature in all instances  Variation point: optional, alternative, or.  Find variation dependencies.  No implementation bias Car Engine Pulls trailer Transmission Manual Automatic

14 Imperative Lists List Ownership External Reference Owned Reference Copy Morphology Length Counter Tracing Mono morphic Poly morphic

15 Interest Rate Products Product Deposit Principle Amount Start Date Maturity Date Currency DEM, USD, EUR,... Interest Amount Swap Fixed Deposit Floating Deposit PeriodConventionRate Simple, Dutch, 360,...

16 Finding Features  Use feature starter sets  Record similarities between instances  Record differences between instances  Organize features into hierarchies  Analyze feature combinations  Record additional feature information  Identify more features than needed

17 Generative Programming  A software engineering paradigm in which  given a particular requirements specification  a highly customized and optimized intermediate or end-product  can be automatically manufactured on demand  from elementary, reusable implementation components  by means of configuration knowledge

18 Domain-Specific Languages  Expressive over variable features  Composition, defaults, dependencies, pragma’s, illegal combinations  Common features built-in / in compiler.  Expression DSL:  Domain-specific computations  Configuration DSL:  Specify a concrete program family member

19 Further Reading  ODM Guide Book  Generative programming chapter 2 + 4, and examples in chs 12, 13, 14.  From the Transform Wiki:  Annotated Bibliography  Little Languages: Little Maintenance?  Draco transformation system and domain engineering methodology.

20 Summary  Domain engineering  Product Line  Economy of Scope  Domain  ODM  Variability  Commonality  Feature Diagrams  Class Diagrams  Generative Programming  Domain Specific Languages

21 Project  Tool support for feature diagrams  Design language apply to simple examples analyze consequences of realistic examples  Implement normalizations  Generate pictures  Suggest class diagram options