What are Requirements?

Transcription

1 Domain Specific Languages and Requirements (Engineering) Markus Voelter What are Requirements? 1

2 a requirement is a singular documented need of what a particular product or service should be or perform. Wikipedia specifies a verifiable constraint on an implementation that it shall undeniably meet or (a) be deemed unacceptable, or (b) result in implementation failure, or (c) result in system failure. Wiktionary 2

3 what a system should do, and with which quality attributes, without presupposing a specific implementation. Mine. Cohesive Complete Consistent Atomic Traceable Current Feasible Unambiguous Mandatory Verifiable Wikipedia 3

4 Brain [Domain Person] Prose Brain [Developer] Code lossy lossy buggy Brain [Domain Person]??? Code 4

5 Requirements & Design Formal requirements specify what a system should do from a domain perspective, and with which quality attributes, without presupposing a specific software implementation, but processable by tools. Mine++ 5

6 Domain Specific Languages DSL A DSL is a focussed, processable language for describing a specific concern when building a system in a specific domain. The abstractions and notations used are natural/suitable for the stakeholders who specify that particular concern. 6

7 general purpose 7

8 domain specific tailor made effective++ specialized, limited used by experts together with other specialized tools 8

9 map DSL Program (aka Model) map automated! GPL Program 9

10 map Generation Transformation Compilation Interpretation Example 1: Pension Fund Specification 10

11 SOLUTION SOLUTION Textual Documentation Insurance Mathematics 11

12 SOLUTION TOOLS Calculation Rules and Tests Intentional Software s Domain Workbench 12

13 SOLUTION Example 3: Radar Systems Engineering Component Definition 13

14 SOLUTION SOLUTION Component Behavior Specification Resulting System Behaviour 14

15 SOLUTION TOOLS Analysis Eclipse Modeling Eclipse Xtext Wolfram Mathematica Mathematica Workbench 15

16 CONTEXT Example 2: Fountains 16

17 SOLUTION SOLUTION Hardware Structure Behaviour 17

18 SOLUTION TOOLS Plus: In-IDE Simulator Unit Test Support Eclipse Modeling Eclipse Xtext 18

19 What if I don t yet have a language? Actually, this is the normal case! Domain Specific Language 19

20 Building Languages As you understand the domain 20

21 develop a language to express it! Language resembles domain concepts 21

22 Then express the design with the language. Clear understanding of the domain from building the language 22

23 Iterate! Understand Domain Domain Expert Language Engineer Define Language Language Engineer Use Language Domain Expert Domain User Iterate! Understand Domain Domain Expert Language Engineer Define Language FORMAL! Use Language FORMAL! 23

24 Like Analysis but Executable! DSL Engineering Tools 24

25 Open Source Eclipse Public License Large wold wide community 25

26 graphical, textual and form-based DSLs Developed by JetBrains Open Source Apache

27 Projectional Editor all kinds of notations, mainly textual Commercial Product Projectional Editor Most flexible notations 27

28 Textual Requirements? Textual Requirements still necessary. 28

29 29

30 Tracing 30

31 Tracing Summary 31

32 Cohesive Complete Consistent Atomic Traceable Current Feasible Unambiguous Mandatory Verifiable Validation Checking Simulation Wikipedia Cohesive Complete Consistent Atomic Traceable Current Feasible Unambiguous Mandatory Verifiable Everything is a model tracing links simple Wikipedia 32

33 Cohesive Complete Consistent Atomic Traceable Current Feasible Unambiguous Mandatory Verifiable Described Formally Wikipedia Cohesive Complete Consistent Atomic Traceable Current Feasible Unambiguous Mandatory Verifiable Domain Expert involved in Definition and Review Wikipedia 33

34 Cohesive Complete Consistent Atomic Traceable Current Feasible Unambiguous Mandatory Verifiable Executable Automatic Refinement downstream, Code Gen. Cohesive Complete Consistent Atomic Traceable Current Feasible Unambiguous Mandatory Verifiable Executable Reward for the additional effort of formalization! 34

35 And Developers??? Languages Technology Evaulation Generators Testing Operations what they want to do anyway! Brain [Domain Person] DSL Code Brain [Developer] 35

36 Getting Started Getting Started 1 Familiarize yourself with some of the tools to better understand their capabilities 36

37 Getting Started 2 Identify a limited, but meaningful aspect of your system and build a prototype Getting Started 3 Evaluate lessons learned (technical) 37

38 Getting Started 4 Think about more strategic places where DSLs can be used, and consider process consequences Getting Started 5 Repeat forever :-) 38

39 THE END..coordinates web skype schogglad xing linkedin