UNIT:3 REQUIREMENT ANALYSIS AND SPECIFICATIONS
3.1 Requirement Gathering And Analysis:
We can broadly divide the requirements gathering and analysis activity into two
separate tasks as requirements gathering and requirements analysis.
Requirement Gathering:
Requirement Gathering is the process of collecting all information needed to
understand what a software system should do.
It is performed by the system analyst during the early stage of software development.
The goal is to identify user needs, system functions, inputs, outputs, and constraints.
Techniques of Requirement Gathering
1. Study of Existing Documentation
The analyst studies all existing documents related to the system before meeting
users.
Examples of documents:
• Current system manuals
• Reports and records
• Forms and registers
• Old software documentation
Purpose:
• Understand the current system
• Identify existing problems
• Reduce time during user interaction
2. Interview
Different categories of users have different requirements.
The analyst interviews all types of users to gather functional requirements.
Users may include:
• End users
• Administrators
• Managers
• Accountants
Example (Library Automation System):
, • Library members
• Librarian
• Accountant
Each user group is interviewed to understand their specific needs.
3. Task Analysis
Users view software as a system that provides services, called tasks.
The analyst breaks each task into step-by-step actions.
Example – Book Issue Task:
1. Authenticate user
2. Check number of books already issued
3. Check whether the book is reserved
4. Issue the book
5. Print book issue slip
Task analysis helps in understanding how a service is performed.
4. Scenario Analysis
A single task may occur under different situations, called scenarios.
The analyst identifies all possible scenarios for a task.
Example – Book Issue Scenarios:
• Book is issued successfully and slip is printed
• Book is reserved and cannot be issued
• Maximum number of books is exceeded
Scenario analysis helps in handling exceptional and alternate conditions.
5. Form Analysis
Forms are analyzed to determine:
• Data input to the system
• Data output from the system
Purpose:
• Identify required data fields
• Understand data flow
• Decide output format
Examples:
3.1 Requirement Gathering And Analysis:
We can broadly divide the requirements gathering and analysis activity into two
separate tasks as requirements gathering and requirements analysis.
Requirement Gathering:
Requirement Gathering is the process of collecting all information needed to
understand what a software system should do.
It is performed by the system analyst during the early stage of software development.
The goal is to identify user needs, system functions, inputs, outputs, and constraints.
Techniques of Requirement Gathering
1. Study of Existing Documentation
The analyst studies all existing documents related to the system before meeting
users.
Examples of documents:
• Current system manuals
• Reports and records
• Forms and registers
• Old software documentation
Purpose:
• Understand the current system
• Identify existing problems
• Reduce time during user interaction
2. Interview
Different categories of users have different requirements.
The analyst interviews all types of users to gather functional requirements.
Users may include:
• End users
• Administrators
• Managers
• Accountants
Example (Library Automation System):
, • Library members
• Librarian
• Accountant
Each user group is interviewed to understand their specific needs.
3. Task Analysis
Users view software as a system that provides services, called tasks.
The analyst breaks each task into step-by-step actions.
Example – Book Issue Task:
1. Authenticate user
2. Check number of books already issued
3. Check whether the book is reserved
4. Issue the book
5. Print book issue slip
Task analysis helps in understanding how a service is performed.
4. Scenario Analysis
A single task may occur under different situations, called scenarios.
The analyst identifies all possible scenarios for a task.
Example – Book Issue Scenarios:
• Book is issued successfully and slip is printed
• Book is reserved and cannot be issued
• Maximum number of books is exceeded
Scenario analysis helps in handling exceptional and alternate conditions.
5. Form Analysis
Forms are analyzed to determine:
• Data input to the system
• Data output from the system
Purpose:
• Identify required data fields
• Understand data flow
• Decide output format
Examples:
