System Analysis Chapter 1
Agile Methods
-Develops System incrementally -Builds a series of prototypes adjusted to new user requirements -Heavy developer user interaction
Transaction Processing (TP)
-Mission critical system -Provides large amount of data -Helps avoid inconsistencies in data (e.i- customer order processing, account receivable)
System Development Tools
-Modeling -Prototyping -Computer-Aided System Engineering (CASE) tools
System Development Life Cycle (SDLC)
-Plan -Analyze -Design -Implement -Support and Security
Waterfall Model
-Requirements -Design -Construction -Testing Maintenance -Evolution
Systems Planning
-Start system planning phase -Describes problem or desired changes
Major System Development Methods
-Structured Analysis -Object- oriented Analysis -Agile Methods (adaptive methods)
Agile Modeling Tools
-Tools that enhance communication -Brainstorming -Whiteboards -Business process modeling
5 key components of an Information system
1. Hardware 2. Software 3. Data 4. People 5. Processes
System
A set of related components that produce specific results
Milestones
A specific identifiable point reached in the process for gauging how far along the process has come
Mission Critical System
A system vital to a company's operation
Knowledge Management
Allows users to enter information by entering keywords or questions in normal English phrases
Internet Business Model
B2C- Business to consumer B2B- Business to business
Systems Analysis
Build logical model of the system
Objects
Classes- Objects inherit properties from classes and may have own properties Methods- Change an object's properties Messages- Request specific behaviors or information from another object
System integration
Data is updated automatically among the different systems (e.i- HR, payroll, accounting systems)
User Productivity
E-mail, voicemail, video, web conferencing, word processing, automated calendars, database management, spreadsheets, desktop publishing, presentation graphics , company intranet, integrated mobile computing system, groupware
Prototyping
Early working version of an information system
Modeling
Graphical representation of a concept or process that can be analyzed tested and modified
Business Process Model (BPM)
Graphically display one or more business processes
CASE tools
Help develop and maintain system
Types of systems
Horizontal- System that can be adapted for many companies (i.e- Payroll systems) Vertical- Systems that is adapted to meet the requirements of a specific type of business or industry (i.e- Blackboard) Legacy system- A company's currently existing system or one that is being replaced
What is Information Technology
It is the combination of the hardware, software, and services that people use to manage communicate and share information
Other Development Methods
Joint Application Development (JAD)- Teams: users, managers, IT staff. Teams based fact finding only Rapid application Development (RAD)- Teams: Users, Managers, IT staff. Compressed version of entire development process.
Inference Rules
Logical rules that identify data patterns and relationships
Systems Support and Security
Maintain, correct errors, adapt to changes in environment (i.e- new tax rate)
Business Profiles
Mission, Functions, organization, products, services, customers, suppliers, competitors, constraints, future direction
System Design
Physical model that satisfies all documented requirements of the system
Object-Oriented Analysis Pros and Cons
Pros- Integrates easily with Object-Oriented languages. Reduces cost. Easy to maintain and expand Cons- maybe too complex for large systems. Maybe unfamiliar to development team
Structured Analysis Pro and Cons
Pros- Traditional method. Popular. Written documents Cons- Changes can be costly, especially in later phases. Requirements may be defined too early. Lacking prototypes to help users describe their needs.
Agile Methods
Pros- Very flexible. Efficient in dealing with change. Reduce risk, frequent deliverables, constantly validates project Cons- Team members needs, strong technical skill, strong communication skills. Risk factors, lack of structure, lack of documentation
Structured Analysis
Represents system in terms of data and processes
Object-Oriented Analysis
Set of software objects that represent: People, Things, Transactions, Events
Systems Implementation
System is constructed, programs written, tested, and constructed
Deliverables
The results of each phase