LESSON 1: Systems Analysis Concepts and Definitions
Information System – interconnected components that collect, process, store,
and deliver information needed for business tasks
Computer Application – system of software that executes a function
Most Popular Information Systems
ESS ---- Strategic level
Desicion ---- Higher level class
Support System
Management
----
Information System
Transaction Processing System ---- Operational level
Transaction Processing Systems (TPS) – process vast volumes of data for
daily business transactions
Management Information Systems (MIS) – systems that work because people
and computers interact purposefully
- Supports wider spectrum of org tasks than TPS
Decision Support System (DSS) – similar to traditional Information
Management System since both depend on a database as data source
Executive Support Systems (ESS) – strategic level, found at the top of the
pyramid
LESSON 2: Systems Analysis and Design
System Analysis – activities which allow to understand and decide what the
new system should be doing (WHAT is required for the new system)
System Design – activities which allow to explain in detail how the system will
be implemented (HOW the system will operate)
Tools and Techniques needed to complete the production
1. Understand the need
2. Capture the vision
3. Define a solution
4. Communicate the vision and the solution
5. Design the solution, or ask others to build the solution
6. Confirm that the solution meets the need
7. Launch the solution application
Systems Analyst – professional who performs analysis and design
Primary Roles of the System Analyst
1. Consultant
2. Supporting Expert
3. Agent of Change
LESSON 3: Systems Development Tools
Modeling – an abstraction of entity. It produces a graphical presentation of a
concept/process
- Physical Models – represents only features of interest
- Narrative Models – can be boiled down to a summary
- Graphical Models – can show main relationships
- Mathematical Models – in the form of a formula
Modeling Techniques:
1. Data Flow Diagrams (DFD)
2. Entity Relationship Diagrams (ERD)
3. Unified Modeling Language Diagrams (UML)
Prototyping
- One of the most popular Rapid Application Development (RAD) methods
- An iterative system development process
Types of Prototyping
1. Type I prototype – eventually becomes the operational system
2. Type II prototype – throwaway model that serves as the blueprint for the
operational system
Development of Type I Prototype
1. Identify User needs
2. Develop a prototype
3. Determine if the prototype is acceptable
4. Use the prototype
Development of Type II Prototype
1. Identify user needs
2. Develop a prototype
3. Determine if the prototype is acceptable
4. Use the prototype
5. Code the operational system
6. Test the operational system
7. Determine if the operational system is acceptable
8. Use the operational system
Computer-Aided Systems Engineering (CASE) Tools
- A technique that uses productivity software called CASE Tools to improve
systems analyst’s routine work
- Provide framework for systems development
General Types of Case Tools
- Display and report generators
- Analysis tools
- Repository
- Documentation generators
- Code generators
Example: Microsoft Project, Microsoft Visio, FourGen, System Architect, …
LESSON 4: Systems Development Methodologies
System Development Methodologies
- set of procedures for developing and maintaining information systems
Popular Methodologies:
- Structured Analysis – Traditional method allowing to grasp the nature of
the system
- Object-oriented Analysis – Latest technique; combines process and data
into things called objects
- Agile Techniques – incorporating new software development patterns
Software Development Life Cycle (SDLC)
- Method/Framework used to design, develop, and test high quality systems
Phases of SDLC:
1. Planning
2. Analysis
3. Design
4. Implementation
5. Support and Security
ISO/IEC/IEEE 12207 – standard for software life-cycle processes
Information System Development Major Sets of Activities
1. Analysis Activities – thorough understanding of the business needs
2. Design Activities – define the architecture and structure of a new system
3. Implementation Activities – actual construction, testing, and installation
Popular SDLC Models
Waterfall Model
- the entire process of developing a software is divided into phases
- Output of one phase is the output for the next phase
Incremental Model
- A series of waterfall cycles
- SDLC is repeated, where every cycle acts as maintenance phase for the
previous one
V-Model
- Promotes continued interaction of development and testing during SDLC
- Project is divided into small incremental builds, all of which are present in
iterations lasting 1-3 weeks each
Spiral Model
- A risk-driven process
- Combines one or more models like waterfall and incremental while
involving rapid prototyping
Big bang Model
- With very little planning
- Best for small projects where requirements or release date is unknown
Unified Modeling Language (UML)
- Allows to specify, visualize, and construct details of information system
and business models
Agile Methods or Adaptive Methods
- Continuously adapting prototypes to the user requirements
Structured Design
- Creates an overall plan for the information system right away
