Requirements

Question 1

What is requirements engineering

Answer 1

THe process of establishing the services that a customer requires from a system and the constraints under which it operates and is developped.

Question 2

What are the 3 phases of requirements phase

Answer 2

Requirement elicitation and analysis
Requirements specification
Requirements validation

Question 3

What is a software requirement

Answer 3

1- A condition or capability needed by a user to solve a problem or achieve an objective.
2- A condition or capability that must be met or possed by a system, due to contract, standard, etc.

Question 4

User vs system requirement

Answer 4

User : Describe the services the system is expected to provide.
System requirements: Detailed descriptions of system functions and operational constraints.

Question 5

Two KEY types of requirements

Answer 5

Functional requirements and Non-functional requirements.

Question 6

What are functional requirements.

Answer 6

Describe what the system should do.
“The system should do ….”
High level statements about system behaviour.

Question 7

What are non-functional requirements

Answer 7

Speicify properties and constrains of the system - reliability, response time and storage requirements.

Question 8

Main concerns of non-functional requirements:

Answer 8

Quantifiability: “system should be bug free” - impractical

Question 9

Main concerns of functional requirements:

Answer 9

Imprecision: may lead to a solution that does not match user expectations
completeness: it should describe all of the system features that are required.
Consistency: conflicts between requirements should be avoided

Question 10

What is the high level classification of non-functional requirements?

Answer 10

POE
product requirements: Must perform in certain way
organizational requirements: process constraints, standards that must be follows.
external requirements: non-product, non-organizational, such as legal, interoperability.

Question 11

Characteristics of Good requirements:

Answer 11

Realism

Validity

Verifyability

Consistency

Completeness

Question 12

Tests to check requirement quality

Answer 12

negation check - “the car shall have an engine”
find the test check - “the system shall be reliable”

Question 13

What is natural language specification

Answer 13

Requirements are written as natural language sentences supplemented by diagrams and tables.
Able to be understood by customers and users

Question 14

Advantages of natural language

Answer 14

Well established practice
Flexible

Question 15

Cons of natural language

Answer 15

lack of clarity - precision difficult without making it hard to read
Requirements confusion - functional and non-functional requirements tend to be mixed up
Requirements amalgamation - several different requirements may be expressed together.

Question 16

Structured specification

Answer 16

An approach to writing requirements where the freedom of the requirements writer is limited and requirements are written in a standard way.

Question 17

Components of a structured text definition:

Answer 17

ID: 1

Function: Generate drug reports

Description: Generates monthly management reports showing the cost of drugs prescribed by each clinic.

Inputs: Clinical prescription data for the month

Outputs: Prescription reports

Question 18

Main concerns of functional requirements

Answer 18

Imprecision: may lead to solution that does not match what the user wanted.
completeness: describe all system features required
consistency: conflicts/contradictions

Question 19

Some metrics of non -functional

Answer 19

Speed, size, reliabilty, portability, robustness