System Analysis And Design (Prelim)

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4 Ps and their techniques > The product>The process>The project
>The problem
step by step activity of the process involved Algorithm
Why is this course important? >Most errors(54%) are detected after coding and testing
>Almost half of all the errors in software(45%) are in requirements and design
>Most errors made during requirements analysis are nonclerical (77%) and may arise because of incorrect facts
Is a set of inter-dependent compounds. (Some of which may be systems in their own right) which collectively accomplish certain objectives. System
___ + ___+___ = information System Information Base + Applications + interfaces = Information System
Differs from other kinds of systems in that its objectives is to monitor/document the operations of some other system, which we can call a target system. Information System
can store, manage, and process large amounts of information for routine business transactions, e.g. , a bank customer account system. Data Processing(DP)
4 main types of information systems >Data Processing
>Inforamation Management
>Decision Support
> Expert System
Provide periodic reports for planning, control and decision making, e.g. , generate end-of-the-month reports, sharing number of new accounts, transaction volume etc. Information Management
Support decision maker by providing information or demand, e.g. , an online system that combines a spreadsheet with a database to help executives draw up a new budget. Decision Support
Capture expertise of decision makers in interpreting information or solving problems and serve as assistants to the users of an information system e.g. , a system that offers advice to a loan manager Expert System
An organized collection of logically related data.
By organize we mean that data are structured soi as to be easily stored, manipulated and retrieved by users.
Database
may be of any size an d complexity Data
Data that has been processed in such a way that it has meaning or relevance to the person using it. Inforamtion
Data that can be described with the characteristics of other data. metadata
3 parts of metadata >Data definition
>Data Structures
>Rules or constraints
2 parts of data structures >Data type
>Data Size
3 types of Datatypes >Character
>Alphanumeric>Numeric
4 Types of information Systems aside from
Data processing, information management, decision support and expert system.
>transaction processing system
>management information system>office information system>personal and work group Information System
are event that serve the mission of the business.

business transaction
information system for business transactions. Transaction processing System
office information system are concerned with getting all relevant information to all those who need it.
blueprint for an IS in an organization Information System Architecture
what does ISA stand for? Information System Architecture
6 key components of Information System Architecture >Data
>processes>network>people
>events and points in time>reasons
-provides a unifying framework into which various people with different perspectives can organize and view the fundamental building blocks of the IS.

A framework for ISA
-stakeholders can be broadly classified in 4 groups; >System Owners
>System Users
>System Designers
>System Builders
Different views of a system >Contextual view>control view
illustrate a contextual view sdadsad
illustrate a control view dsadsad
The vast majority of systems are not made by people: they exist in nature and, by and large, serve their own purpose. It is convenient to

NATURAL SYSTEMS

2 basic subcategories of natural System >Physical System
>Living Systems
are interesting to study because as pesky humans, we sometimes want to modify them. We also develop a variety of man-made systems, so it is often important to be able to model those systems to ensure that we understand them as fully as possible. Physical systems
encompasss all the myriad animals and plants arounds us, as well as our own human race. Living systems
19 critical subsystems of living systems >reproducer
>boundary
>ingestor
>distributor
>converter>producer
>matter-energy storage subsystem>extruder
>motor
>supporter
>input transducer
>internal transducer
>channel and net
>decoder
>associator>memory
>decider
>encoder
>output transducer

a number of systems constructed , organize and mainained by humans. Man-made Systems
Why should some information processing systems not be automated? >cost
> convenience
>security
>maintainability
>politics
>Inability to articulate policy and procedures in precise fashion
>Inability to automate a system w/in the required amount of time
man-made systems that interact with or are controlled by one or more computers Automated Systems
components of an Information System >Computer Hardware
>Computer Software
>people
>data
>Procedures/ processes
formal policies and instructions for Operating System procedure
the information that the system remembers over a period of time data
System programs such as OS, database systems and telecommunication control programs, plus application programs that carry out the functions that the user wants. Computer software
CPUs, disks, terminals, printers, magnetic tape drives, and so on Computer hardware
systems that came into being by natural process Natural System
Systems in which human beings intervened through a component, attributes or relationships. human made system/ man-made system
The process of developing a system or software to meet certain requirements. It covers many activities; starts from understanding why the system should be built, studying the project feasibility, analyzing problems, choosing the system design and architecture, implementing and testing it and delivering the system to the user. Structured development life Cycle(SDLC)
is a step-by-step process for developing high-quality information systems. System Analysis and design
combines inforamtion technology, people and data to support business requirements Information System
When a company develops its own information System, the system is called ____ In-home system
purchased systems from outside vendors software packages
A system vital to a company's operations Mission-critical system
Is data that has been transformed into output that is valuable to users. information
is a set of related components that produces specific results. System
consists of everything in the physical layer of the information system Hardware
refers to the programs that control the hardware and produce the desired results. Software
2 types of software >System Software
>application software
is the raw material that an IS transform into useful information data
the tasks and business functions that users, managers and IT staff members perform to achieve specific results. Processes
are the people who intract with an IS, both inside and outside the company End users
include administrators, managers, technicians, sales staff and corporate officers. internal users
include customers who trafck their orders on the company's website External users
users who use a customer's system to plan their manufacturing schedules suppliers
3 types of users: >internal users
>external users
>suppliers
manages hardware components, which can include a single work station or a global network System software
consists of programs that support day-to-day business functions and provide users with the information they need. Application software
2 types of Application Software; >Horizontal System
>Vertical System
A system such as an inventory or payroll application that can be adapted for use in many different types of companies. horizontal system
is designed to meet the unique requirements of a specific business or industry. such as a web-based retailer, medical practice etc. Vertical System
used by system analysts to represent a company's operations and information Business process modelling
is an overview that describes a company's overall functions, processes, organization, products, services, customers, suppliers, competitors , contraints and future direction. Business Profile
- make it easier for managers and system analysts to understand day-to-day business operations business models
-it is a graphical representation of one or more business process that a company performs, such as accepting an airline reservation, selling a ticket or crediting a customer. Business model
Describes a specific set of transactions, events, tasks and results business process
traditonal IT comapnies >product oriented
>service oriented
New kinds of business >Internet dependent
>brick-and-mortar companies
another name for internet dependent companies dot-com(.com) company
its primary business depends on the internet rather than a traditional business channel. Google, yahoo, AOL and ebay are examples of pure dot-com companies. Internet dependent / dot-com comapny
they conduct business for physical locations
Ex) Walmart, target
Brick-and-mortar comapanies
internet based commerce. e-commerence(electronic commerence)
/I-commerence (Internet commerence)
Phases of system development life cycle >preliminary study
>feasibility study
>detailed system study>system analysis>system design
>coding
>testing
>implementation
>maintenance
2 main sectors of e-commerence B2C (business to consumer)
B2B (business to business)
using the internet, consumers can go online to purchase an enormous variety of products and services. Business-to-consumer
The volume is many times greater.
It's transsactions are many times greater than B2C.
business to business
online trading marketplaces initially were developed as company-to-company data sharing arrangements. Usually over private communications network. Used to plan productions, adjust inventory levels, or stock up. Electronic Data Interchange (EDI)
Enabled company-to-company traffic to migrate to the internet which offers standard protocols, universal availability, and bus communication costs is flexible data description language that allows metabased communication between different hardware and software environments.
Extensible markup language
what does XML stand for? Extensible mark-up langauge
B2B sites where buyers, sellers, distributors and manufacturers can offer products, submit specifications and transact business. Supplier relationship management
examples of internet based systems; websphere and .Net
refers to information systems that support company-wide operations and data management Enterprise computing System
Systems provide cost effective support for users and managers throughout the compnay
ex:) forecast customer demand for rental cars at hundreds of locations.
Enterprise resource planning(ERP)
Process data generated by day-to-dat business operations Transaction process(TP) system
provide job related information to users at all levels of company. Business support system
managers are the primary users. management information systems (MIS)
uses high frequency radio waves to track physical objects, such as shipping cartons, by using tags that can be scanned. Radio Frequency Identification(RFID)
are called expert systems because they simulate human reasoning by combining a knowledge base and inference rules that determine how the knowledge is applied. Knowledge management systems
consists of a large database that allows users to find information by entering a symptom, problem, or question. knowledge base
logical rules that identify data patterns and relationship. interface rules
used by many knowledge management systems. It allows inferences to be drawn from imprecise relationships. fuzzy logic.
examples include e-mail, voicemail, fax, video conferencing, word processing, automated calendars, databse management, spread sheets, desktop publishing, presentation graphics, company intranets, and highspped internet access. It also includes groupware. Technology that improves productivity. User Productivity system
programs that run on a company intranet and enable users to share data , collaborate on projects, and work in teams.
EX:) groupwise offered by Novell
Groupware
defines a company's overall mission and goals strategic plans
produces a graphical representation of a concept or process that systems developers can analyze, test and modify. modelling
descrives he information that a system must provide business mode/ requirement model
describes the data structure and design data model
ascribes objects which combine data and processes. object model
describes the design and protocols of telecommunication links. network model
describes the logic that programmers use to write code modules. Process model
Is an early working version of an information system prototype
Computer-aided system engineering is also called? computer-aided software engineering
is a technique that uses powerful software called CASE tools, to help systems analysts develop and mainati nthe systems. Computer-aided systems engineering
provide an overall framework for system development and suport a wide variety of design methodology including structured analysis and object-oriented analysis. CASE tools
most popular method for developing IS, which is a traditional method that still is widely used. Structured Analysis
Is a newer approach that many analysts prefer Object oriented analysis
phases of structured analysis for planning analyzing, designing , implementting and supporting an IS. System development life cycle
structured analysis is a predictive approach. Predictive Approach
focuses on processes that transform data into useful information. PRoces-centered
processes that cat on the data. objects
characteristics of an object which it inherits from its calss or posses on its own. properties
built-in processes that can change an object's properties. methods.
requests specific behavior on information from another object. message
SDLC is also called_______ waterfall method
where planning, analysis and design tasks interact conitiniously to produce prototypes that can be tested and implemented. Interactive model
is more flexible than SDLC and constant dialog among users, managers, and system developers. Interactive model
typically uses a spiral development model, whic hbuilds on a series of interactions. Adaptive method
represents a series of interactions or revisons based on usre feedback. spiral model
usually begibs with a formal request to tyhe IT department called a system request. System planning phase.
describes probles or desired changes in an information system or business process System request
to identify the nature and scope of the business opportunity or problem preliminary investigation
a key part of preliminary investigation that reviews anticipated costs and benefits and recomends a course of action based on operational, technical , economic, and time factor. Feasibility study
this pahse is for building a logical model of the new system. System Analysis phase
the purpose of this pahse is to create a blueprint that will satisfy all documented requirements for the system. System design phase.
the first step to system analysis phase wher you investigate business processes and document what the new system must do. requirements modelling.
the ed product of the systems analysis phase. describes management and useer requirements, costs and benefit and outlines alternative development strategies. system requirements
where the result of tsystem design phase is doucumented. System design specification
the result is presented to management and users for review and approval. System design specification
Phase when the new system is constructed systems implementation phase
an assesssment to determnine whether the system operates properly and if costs and benefits are with in expectations. Systems evaluation
phase when the IT staff maintains, enhaces and protects the system Systems operation,support and security phase
another adoptive method which focuses on n intensely interactive process between developers and users rather than an overall project goal. Extreme programming (XP)
Use teams composed of users , managers, and IT staff. joint applications development (JAD) and Rapid Application Development (RAD)
focuses of team based fact-finding which is only one phase of the developmenty process. Joint applications development (JAD)
is more like a compressed version of the Entire process. Rapid Applications development (RAD)
Other development methods: > Rational unified Process (RUP)
>Microsoft Solutions Frameworks (MSF)

offers a flexible, interactive proces for managing software development projects that can minimize risk, ensure predictable results and deliver high-quality software on time. Rational Unified process (RUP)
documents the experiences of its own software development teams. Microsoft solutions frameworks (MSF)
is the process of planning, scheduling, monitoring, controlling and reporting upon the development of an information system Project management
System development guidelines 1.) Planning
2.) Involve the users throughout the development process3.)Listening is very important4.) Use project management tools to identify and milestones5.) remain flexible6.) develop accurate cost and benefit information
includes 6 main functions: application development, system support and security, user support, db administration, network administration and web support. technical support
provides vital protection and maintenance service for system hardware and software, including enterprise computing systems, networks, transaction processing systems and corporate IT infrastructure. Systems support and security
installs and configures the work stations deployment team
provides technical information, training and productivity support.
also Called a help desk. or information center (IC)
User support
involves db design, management, seucirty, backup and user access. database administrators.
includes hardware and software maintenance, support and security. network administrator.
is a vital technical support function web support
web support sepcialists that support a company's internet and intranet operations. Webmasters
team that reviews and tests all applications and systems changes to verify specifications and software quality standards. Quality Assurance (QA)
verifies that an individual demonstrated a certain level of knowledge/skill on a standardized test. certification
is the set of beliefs, rules, traditions, values and attitudes that define a company and influences its users of doing business. Corporate Culture