Approaching System Development (102L2)

·      Using Object Oriented Methodology for complete Software Application Development 

Start below activities in Inception Phase,

1.     Write brief “Vision” draft about the project

2.     Identify users’ goals and supporting use cases

3.     Write use cases and Supplementary Specification document

a.     Use cases (Ivan Jacobson, 1986)

                                                                 i.     Are stories using system functionality to meet desired system goals

                                                               ii.     Define Use-case model at requirements stage

                                                              iii.     It defines system functionality (what system will do) and environment

                                                              iv.     It includes interactions between Actors and System for realizing related scenarios such as success or alternate scenarios (failure).

                                                               v.     Scenarios yields observable results for particular actor

b.     Supplementary Specification includes,

                                                                 i.     Quality properties (Non Functional Requirements)

                                                               ii.     constraints

1.     Hardware (Linux due to company roadmap)

2.     Software (only from registered vendors)

3.     Development tools (eclipse)

                                                              iii.     Internationalization and Localization

                                                              iv.     Licensing and compliance

                                                               v.     Business rules

                                                              vi.     Business Contingency plan

                                                            vii.     Users, Installation manual and Help

                                                           viii.     Standard references (development, test, release)

4.     Refine the Vision during next iterations and phases

5.     Create Software Development Plan

Keep refining all above activities in the further phases

Start below activities in Elaboration Phase,

1.     Create Domain Model using Use case and Vision

2.     Write software architecture document

3.     Create Implementation Model

4.     Create Test plan

·      Online Banking System (ATM like system)

o   Requirements

Automate existing manual banking functions to serve Prospects and Customers efficiently and cost effectively. The scope is limited to below functions under Phase-I of this project.

§  Scope :

·      Customer registration system

·      Account transactions includes : deposit, withdrawal, transfer

·      Security management includes : User Authentication and maintenance

·      Some features will be available using web or mobile clients

o   Portfolio Analysis

o   Money Transfer

·      Transaction audit facility for Auditors and Customers

§  Use-case Model

§  Use-case Goals

Use case	Description
Manage Users	User data maintenance and security information will be managed by System Administrator
Authenticate Users	Authenticate Customer login information using existing security service
Money Deposit	Customer does money deposit which finally updates core banking system
Money Withdrawal	Customer does money withdrawal which finally updates core banking system
Money Transfer	Customer does money transfer to other bank accounts  which finally updates core banking system
Transaction Analysis	Customer and Auditor can view account transactions
New Account Registration	Prospect submit form to open new account with the bank which will be authorized or rejected by bank manager

o   Domain Model

o   Build Relationship between Domain Objects

§  Class Diagram

o   Add responsibilities

§  Add methods to each identified object

o   Add System Specific Objects

§  Such as TransactionManager above

o   Re-define objects relationship if necessary

o   Use MVC and layer components

o   Define non-functional requirements (Quality Properties)

§  HA (High Availability) and Performance requirements

§  Security Model

§  Internationalization and Localization

o   Do implementation using Java along with Unit test cases (JUnit).

o   Build GUI presentation layer.

{*Properly use Abstraction, Inheritance, Encapsulation and Polymorphism principles}

Object and Class

1) Object and Class

Class is template to create objects and represents classification of objects such as Employee, which is a class for the objects such as “Tom”, “Joe”, “Hanako”

2) OO-Analysis

            - Break the requirements into smaller problems (decompose the requirements)

            - Try to understand “WHAT” is require instead of “HOW” to implement

- Create conceptual domain model (only consider domain specific objects

   and  not system specific)

Such as in case of  our “Online Banking System” (OBS) Project following is a conceptual design (domain model)

3) OO-Design

o   For each identified object find out how they will cooperate and collaborate with each other to understand the relationship between them.

o   Then assign responsibility by adding properties and methods (behavior) to each object

o   Add helper objects (system specific and not business specific)

Such as TransactionManager

4) OO-Implementation:

o   Implement the design using specific OO Language, such as Java

-       Create new project in eclipse : OnlineBankingSystem

o   Create class : Customer

public class Customer {

       private String lastName;

       private String firstName;

       public String getLastName() {

              return lastName;

       }

       public void setLastName(String lastName) {

              this.lastName = lastName;

       }

       public String getFirstName() {

              return firstName;

       }

       public void setFirstName(String firstName) {

              this.firstName = firstName;

       }

}