Analysis Modeling - Introduction to Software Engineering | CS 230, Study notes of Software Engineering

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CS 230 Introduction to Software Engineering

Analysis Modeling Structured Analysis

CS 230 Introduction to Software Engineering

Objectives of the Analysis Model

1.^

To describe what the customer requires

2.^

To establish a basis for creation of a softwaredesign

3.^

To define a set of requirements that can bevalidated once the software is build

CS 230 Introduction to Software Engineering

Structure of the Analysis Model (Contd)

Data dictionary • core of the model • repository that contains^ descriptions of all data^ objects consumed or^ produced by the software

State – Transition Diagram Entity-RelationshipDiagram

DataFlowDiagram DataDictionary

CS 230 Introduction to Software Engineering

Data Dictionary

-^ Name -^ the primary name of the data or control item, the data store or an external entity • Alias -^ other names used for the first entry -^ Where used/how used -^ a listing of the processes

that use the data or control item and how it is used(e.g., input to the process, output from the process,as a store, as an external entity • Content description

-^ a notation for representing

content • Supplementary information

-^ other information

about data types, preset values (if known),restrictions or limitations, and so forth

CS 230 Introduction to Software Engineering

Structure of the Analysis Model (Contd)

State – Transition Diagram Entity-RelationshipDiagram

DataFlowDiagram DataDictionary

Entity-Relationship Diagram(ERD)• Data modeling• Relationship between data objects• Attributes of each data object canbe described using a data objectdescription

CS 230 Introduction to Software Engineering

Structure of the Analysis Model (Contd)

State – Transition Diagram Entity-RelationshipDiagram

DataFlowDiagram DataDictionary

Data Flow Diagram (DFD)• Functional modeling andinformation flow• Indicates how data aretransformed as they move throughthe system• Depicts the functions thattransform the data flow• Each function description iscontained in a processspecification

CS 230 Introduction to Software Engineering

Data Modeling - ERD

-^ What are the primary data objects to be processedby the system? •^ What is the composition of each data object andwhat attributes describe the object? •^ Where do the objects currently reside? •^ What is the relationship between each object andother objects? •^ What is the relationship between the objects andthe processes that transform them?

CS 230 Introduction to Software Engineering

Data Modeling - ERD

-^ Defines all data that are input, stored, transformed,and produced within application •^ Especially useful for applications in which data andrelationships that govern data are complex •^ Unlike DFD, ERD consider data independently ofthe processing that transforms the data

CS 230 Introduction to Software Engineering

Data Objects, Attributes, & Relationships Objects:

Attributes:

Relationships:

NameAddressAgeDriver’s license number

Owns

MakeModelID numberBody typeColor

CS 230 Introduction to Software Engineering

Data Objects

-^ External entity – anything that produces orconsumes information^ • Thing (e.g., car)^ • Occurrence (e.g., telephone call)^ • Event (e.g., alarm)^ • Role (e.g., student)^ • Organizational unit (e.g., Dept. CSEE)^ • Place (e.g., ESB)^ • Structure (e.g., students file)

CS 230 Introduction to Software Engineering

Attributes

-^ Define properties of a data object •^ Take on one of three different characteristics^ • Name an instance of the data object^ • Describe the instance^ • Make reference to another instance in another table •^ One or more attributes must be defined as anidentifier which becomes key when we want to findan instance of the data object •^ The set of attributes is determined throughunderstanding of the problem context

CS 230 Introduction to Software Engineering

Relationships

Book^ Book

BookstoreBookstore

orders displaysstockssells returns

CS 230 Introduction to Software Engineering

Modality

-^ Modality is^ • 1 if an occurrence of the relationship is mandatory^ • 0 if there is no explicit need for the relationship to occur

or the relationship is optional

CS 230 Introduction to Software Engineering

Copyright © K.Goseva 2006

Cardinality and Modality

Each faculty member advises many students, each student has only one advisor

Cardinality: one

Cardinality: many

Cardinality: one

Every faculty member may not be advisor, each student must have an advisor

Faculty^ Faculty

StudentStudent

Advises

Modularity: mandatory

Modularity:optional