Fundamental of System

SAD is a process for analyzing an organization's needs and designing new information systems to meet them.

System Analysis and design Aug 1, 2025 0 7 Add to Reading List

Definition of System:

A system is a set of interrelated components working together toward a common goal by accepting inputs and producing outputs in an organized transformation process.

Example:
A Banking System includes:

Customer database
Account management

Transaction processing
All parts work together to handle banking services

Fundamentals of a System (Key Elements)

Element	Description	Example
1. Input	Data or material received by the system for processing	ATM card + PIN entered
2. Process	The action done to transform input into output	Verify PIN, check balance
3. Output	The result produced by the system	Cash dispensed, receipt
4. Feedback	Output that is returned to improve future performance	Customer feedback on service
5. Control	Rules and decisions to guide the system's operation	Limit on daily withdrawal
6. Environment	Anything outside the system that affects or interacts with it	Government regulations, users
7. Boundary	Defines the scope of the system — what's included and what's not	ATM software ≠ Bank policy
8. Subsystems	Smaller parts of a system that do specific tasks	Loan management, account info
9. Interface	Point where system interacts with users or other systems	ATM screen, banking app

Block Diagram of a System:

Example: Library Management System

Element	Description
Input	Book details, student details, borrowing request
Process	Verify user, check book availability, record transaction
Output	Issue slip, due date, updated database
Control	Rules (e.g., maximum 3 books, return within 15 days)
Feedback	Late return penalty reports, usage logs
Boundary	Only library-related activities included
Environment	Students, librarians, book vendors

Scope of a System

The scope of a system refers to the area of operation it covers — its functions, limits, and interactions with users or other systems.

Functional Boundaries
– What the system will do (and what it won’t).
– e.g., A result management system handles only marks, not fee payment.
User Types
– Who will use the system? Admins, students, staff?
Inputs/Outputs
– What data will be entered and what will be produced?
Integration with Other Systems
– Will it work with other software?
Time & Cost Limits
– Deadline and budget for building the system.

Example:
The scope of a hospital management system includes:

Patient registration
Doctor appointments
Billing
But excludes insurance processing.

Nature of a System

The nature of a system means its features or characteristics — what makes it behave like a system.

Key Characteristics of a System

Characteristic	Explanation	Example
1. Organization	All components are well-arranged and connected	Library system: issue, return, search
2. Interaction	Parts of the system affect each other	In payroll, employee hours affect salary
3. Interdependence	All subsystems rely on each other	Mark entry → total marks → result
4. Integration	All parts combine to form one working unit	Student data shared across modules
5. Goal-Oriented	Every system works toward a clear goal	Banking system: secure money mgmt.
6. Dynamic	Systems change with time and environment	School system updated for NEP
7. Adaptive	Can respond to internal and external changes	Adds online classes after COVID
8. Abstract or Physical	Can be tangible (hardware) or intangible (software, process)	ERP software (abstract), server (physical)