DESIGN PHASE

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SADCW_7e_Chapter07.pptx

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Chapter 7

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Second level

Third level

Fourth level

Fifth level

Defining the System Architecture

Chapter 7

Systems Analysis and Design in a Changing World 7th Ed Satzinger, Jackson & Burd

Chapter 7: Outline

Anatomy of a Modern Information System

Architectural Concepts

Interoperability

Architectural Diagrams

Describing the Environment

Designing Application Components

Learning Objectives

Explain architectural concepts that influence system design, including ubiquitous computing and software, components, protocols, interoperability, and distributed architectures

Describe and draw location, network, and deployment diagrams

Describe a system’s environment by drawing architectural diagrams and answering key questions

Design larger application components based on use cases and other analysis models

Overview

An important part of new system development is choosing appropriate technologies

Explain and provide a summary of technology and architectural concepts

describe the details for the activity – Describe the Environment

Describe the details for the activity – Design the application components

Activities of “Design System Components”

Anatomy of a Modern System – Computing Devices

Server – manages shared resources and enables users and other computers access to these resources

Personal computing devices or clients

Desktops, laptops, tablets, smartphones…

Simplified architecture for application (Amazon.com)

Server Farm –

Very large databases and very high use

Anatomy - Networks (1 of 2)

Computer network – hardware, software, transmission media

Internet backbone –

High-capacity with high-bandwidth trunk lines and large high-speed computers

Owned by governments and telecom companies

Local area network (L A N) –

Small network for a single site

World Wide Web (W W W)

All the interconnected resources accessed through the Internet

Anatomy - Networks (2 of 2)

Uniform Resource Locator (U R L)

The identifier for the Web to locate a particular resource

Hyperlink –

The U R L of a resource embedded within another resource

Anatomy – Software (1 of 3)

Application software – programs that perform work for users

Either a custom app or a Web-based application

App –

A custom program usually for a laptop or smartphone

System Software –

Behind the scene software, works as glue to hold everything together

Anatomy – Software (2 of 3)

Anatomy – Software (3 of 3)

Web-Based Applications

Uses a web browser

Accessed through a U R L

Resides on a Web server

Uses standard I P protocols

Embedded Software

Software apps or functions embedded within another app, such as within a browser or O/S

Toolbars, Plug-ins, Widgets

Anatomy – Protocols

Protocol

A set of languages and rules to ensure communication and data exchange between hardware and software

Network protocols

Virtual Private Network (V P N)

Creates a private network but on the Internet by using secure technologies and encryption

Anatomy – Software and Protocols

Anatomy – Web Protocols

H T M L (hypertext markup language)

Protocol for the structure and content of a Web page

X M L (extensible markup language)

An extensions of H T M L that enables defining semantics of tags

H T T P (hypertext transfer protocol)

Defines format and content for transfer of Web documents

H T T P S (hypertext transfer protocol secure)

Encrypted and secure http transfers

Architectural Concepts

Technology architecture

Computers, network computers and hardware, and system software

Application architecture

The software programs and their configuration

Software as a Service (SaaS)

SaaS

No software is installed on the user’s device

Application services is accessed remotely

User data is isolated and stored on common servers

Web Services

Web service

Software function that is executed with Web standards

Access via a U R L

Inputs sent via the U R L

Executes remotely

Data returned within a Web page

Distributed Architectures

Client/Server architecture

Software design with part of the application on a server and part on the client

Distributed Architecture

Three-Layer architecture

Client/server architecture with application divided into view layer, logic layer, and data layer

View layer – the user interface

logic layer – program logic to implement the functions

data layer – the functions to access the data

Three Layer Architecture

Interoperability

The ability of an application to interact with other software

Important characteristic in current development projects

Understand the environment

Reuse software existing components (purchased or in-house)

Build components considering interoperability

Combine all components into a solution system

Diagrams for System Architectures

Location Diagrams

Identify geographical placement of hardware, software, and users

Diagrams for System Architecture (1 of 2)

Network Diagrams

How the application software is deployed across the hardware and system software

Diagrams for System Architecture (2 of 2)

Deployment Diagrams

How the components of a network are interconnected

Describing the Environment (1 of 2)

Key Questions to help describe accurately

What are the key features of existing or new environment

O/S, system software, networks, tools

What are the external systems or D B M S s

What kind of interaction

What is the data

What are the protocols

What kind of security

Describing the Environment (2 of 2)

Key Questions to help describe accurately

What devices will be required

Protocols for devices

Security

What A P I s

What user-interface technology will be used

Where and who are users, and what skills

What hardware and devices

What client O/S will be used

Security requirements

What A P I s are needed

R M O Environment - Existing

Current environment prior to new development

R M O Environment – Proposed (1 of 2)

More mobile devices and apps

Web application software and content

Social networking applications

Security issues

External hosting of portions

R M O Environment – Proposed (2 of 2)

Designing Application Components

Application Component Boundaries

Which components perform which functions

How to group functions to build components

Actors – what functions to particular actors use

Shared data – what functions use the same data

Events – what functions occur in common business events

R M O C S M S Application Architecture (1 of 3)

Grouping by customer actor – part 1

Use case	User/actor	Domain class(es)	Event(s)	Group
Create phone sale	Phone sales representative	ProductItem, InventoryItem, saleItem, Sale, SaleTrans	Customer request while shopping by phone	A
Create store sale	Store sales representative	ProductItem, InventoryItem, saleItem, Sale, SaleTrans	Customer request while shopping in store	B
Create/update customer account	Customer, phone or store sales representative	Customer, Account, Address	Customer request or sale to a new customer	C
Look up order status	Shipping, customer, management, phone or store sales representative	ProductItem, InventoryItem, SaleItem, Sale, SaleTrans, Shipment, ReturnItem	Customer, representative, shipping, or management request	C
Track shipment	Shipping, customer, management, phone or store sales representative	Shipment, Shipper, SaleItem	Customer, representative, shipping, or management request	C
Create item return	Customer, phone or store sales representative	SaleItem, ReturnItem	Customer requests return	C
Search for item	Customer, phone or store sales representative	ProductItem	Customer request while shopping online, by phone, or in store	C
View product comments and ratings	Customer, phone or store sales representative	ProductItem, ProductComment	Customer request while shopping online, by phone, or in store	C
View accessory combinations	Customer, phone or store sales representative	ProductItem, AccessoryPackage	Customer request while shopping online, by phone, or in store	C

R M O C S M S Application Architecture (2 of 3)

Grouping by customer actor – part 2

Use case	User/actor	Domain class(es)	Event(s)	Group
Fill shopping cart	Customer	ProductItem, InventoryItem, CartItem, OnlineCart	Customer request usually after sale completed	D
Empty shopping cart	Customer	ProductItem, InventoryItem, CartItem, OnlineCart	Customer request while shopping online	D
Check out shopping cart	Customer	ProductItem, InventoryItem, CartItem, OnlineCart, saleItem, Sale, SaleTrans	Customer request while shopping online	D
Fill reserve cart	Customer	ProductItem, InventoryItem, CartItem, OnlineCart	Customer request while shopping online	D
Empty reserve cart	Customer	ProductItem, InventoryItem, CartItem, OnlineCart	Customer request while shopping online	D
Convert reserve cart	Customer	ProductItem, InventoryItem, CartItem, OnlineCart	Customer request while shopping online	D

R M O C S M S Application Architecture (3 of 3)

Grouping by customer actor – part 2

Use case	User/actor	Domain class(es)	Event(s)	Group
Rate and comment on product	Customer	Customer, ProductComment, ProductItem	Customer request usually after sale completed	E
Provide suggestion	Customer	Customer, Suggestion	Customer request while shopping online	E
Send message	Customer	Customer, Message	Customer request while shopping online	E
Browse messages	Customer	Customer, Message	Customer request while shopping online	E
Request friend linkup	Customer	Customer, FriendLink	Customer request while shopping online	E
Reply to linkup request	Customer	Customer, FriendLink	Customer request while shopping online	E
Send/receive partner credits	Customer	Customer, CustPartnerCredit, PromoPartner	Customer request while shopping online	E
View ”mountain bucks”	Customer	Customer, Sale	Customer request while shopping online	E
Transfer ”mountain bucks”	Customer	Customer, Sale	Customer request while shopping online	E

R M O C S M S Deployment Diagram

Three-layer design with user components grouped by user functions

R M O C S M S Component Integration

Subsystem integration and data flows

R M O C S M S Data Ownership

Who “owns” the data

System of record

What system is responsible to maintain the data

What system has a copy or can access the data

Summary (1 of 3)

Anatomy of a Modern Information System

Consist of computing devices, networks, software, and protocols

Deployed as stand-alone software, network based, Web based

Architectural Concepts

SaaS – software as a service

Web services

Distributed architectures

Client/server and three-layer architecture

Summary (2 of 3)

Interoperability

Getting all the components to work together

Architectural diagrams

Location diagrams

Network diagrams

Deployment diagrams

Summary (3 of 3)

Describing the Environment

External systems

Technology architecture

Key questions requiring answers

Designing Application Components

Application component boundaries

Grouping functions into components

System of record – who owns the data