domain analysis & data modeling

Domain Analysis & Data Modeling

Course IN4308Master Computer Science

Delft University of Technology

Eelco Visserhttp://eelcovisser.org

Lecture2

Thursday, February 11, 2010

Course Goal

Learn to design and implement domain-specific languages

Understand DSL design choices and make reasoned decisions about their application


ProblemDomain HLL MachineDSL

domain-specific models reduce gap between problem domain and implementation

Model-Driven Software Development


Why domain-specific languages?

Domain-specific models

- increase level of abstraction

- are closer to problem domain

- are smaller

- are easier to write

- are easier to maintain


What is a model?

A model

- is a simplification of a system

★ abstraction, description, specification, information

- can answer questions in place of actual system

★ analysis, inference, predictions

- is used for a purpose

★ understanding, planing, risk analysis, ...


How are ‘models’ different from ‘code’

- Models are just another form of code

- Are models better than code?

★ no, models provide different level of abstraction

★ depends on the purpose

★ how well does DSL fit purpose

★ should be easier to analyze

- Continuum of abstractions

- Abstraction => giving up control


“Far better at some key things”


How do we make DSLs?


Model

Syntax

DSL

Checks

Editor

Transformation

GeneratorSoftwareSystem

generate

described by

consists of


What makes a DSL?


What makes a DSL?

The DomainThursday, February 11, 2010

What is a domain?


Domain Engineering is the activity of collecting, organizing, and storing past experience in building

systems or parts of systems in a particular domain in the form of reusable assets (i.e. reusable work

products), as well as providing an adequate means for reusing these assets (i.e., retrieval, qualification,

dissemination, adaptation, assembly, and so on) when building new systems

Source: Czarnecki & Eisenecker, Generative Programming, 2000


DomainAnalysis

DomainDesign

DomainImplementation

RequirementsAnalysis

ProductConfiguration

Integrationand Test

product

domainknowledge

domainmodel

system familyarchitecture

requirements

requirements

requirements

features configuration

Domain Engineering

Application Engineering

Source: Czarnecki & Eisenecker, Generative Programming, 2000

DSLscomponentsgenerators


Application Domain = Family of Systems

Identify

- Commonality

★ What is the same in all systems?

★ Can be reused between applications

★ Standard components

★ Generated code

- Variability

★ What is different between systems?

★ Needs to be defined for each application

★ Using domain-specific language


Domain analysis in application engineering

ProblemDomain

SolutionDomain

implement

validate


Domain: “A sphere of knowledge, influence, or activity”

Eric Evans, Domain-Driven Design, 2004

“The subject to which the user applies a program is the domain of the software”


System


Interaction Design

Domain-Driven Design

Data Model Design


Interaction Design


X + Computer = Computer

Cognitive Friction

Dancing Bearware


Analysis

Software design driven by developers

- implementation model is leading

- convenient for developer, not for user

- developers drive design ‘from the back seat’


User Personas

Goals (not Tasks)


Polite software is

★ interested in me

★ forthcoming

★ has common sense

★ anticipates my needs

★ is responsive

★ is taciturn about its problems

★ is well informed

★ is perceptive

★ is self-confident

★ stays focused

★ is fudgable

★ is trustworthy


Interaction Designrequires

Big Up Front Design


How can we integrate interaction design in software engineering?

Can programmers be interaction designers?Thursday, February 11, 2010

Some lessons that I have tried to apply

- Direct manipulation

★ edit where you view

- No confirmations

★ no destructive, catastrophic actions

- No inaccessible actions/links

★ apply access control to source of navigation

- Limitations for user should be based on policy

★ policy: rules based on domain requirements

★ mechanism: inconvenient to implement


CourseManagement

System

Student

Lecturer

UniversityAdministrationGuests


What goals does/should ‘The Department’ support?



“Every software program relates to some activity or interest of its use. That subject area to which the user applies a program

is the domain of the software”



“A model is a selectively simplified and consiously structured form of knowledge”



Ubiquitous Language: “a language structured around the domain model and

used by all team members to connect all the activities of the team with the software”


[Course]-*[Student][Course]-*[Lecturer][Course]-*[Assistant][Course]-*[Lecture][Course]-*[Assignment][Assignment]-*[Submission][Submission]1-1..[Student][Lecture]-[Slides][Lecture]-[Notes]

http://yUML.me: a DSL for drawing UML diagramsThursday, February 11, 2010

http://yUML.me

http://yUML.me

Collaboration on Assignments

Scenario 1

- Piet starts submission for Design 1

- Jan starts submission for Design 1

- Piet and Jan want to work together on Design 1

Scenario 2

- Piet, Jan work together on Design 1

- They want to split


- Creating submissions

★ should be enrolled

- Can be partner if

★ no active submission

★ #students < limit

- Start submission if

★ not part of active submission

Binding Students to Submissions


Submissions & Deadlines

- Edit assignment after submission?

★ before deadline

★ after deadline

★ after/during grading

- Status of assignment not submitted before deadline?

- Submitting partial assignments?


Domain analysis is more than drawing a class diagram

Domain Model = Concepts + Interaction

System


A domain-specific language for domain-driven design


entities with propertiesThursday, February 11, 2010

‘Physical’ Data Models


From conceptual to physical data model

In memory

- objects

- hash maps

Persistent data

- Records in RDBS

- XML

- JSON

- Text (csv)


Schedule

Lab this week:

★ WebDSL tutorial => submit page index

★ Make design proposal for a web application

★ Entity declarations for your web application

Read/think:

★ Read: interaction design, domain-driven design

★ Case 1: analysing issues in digital library domain

Next week

★ Web Abstractions


domain analysis & data modeling

Education

application domain

particular domain

domainspecic languagethursday

domain requirements

gap betweenproblem domain

analysis software design

code models

dsl design choices