Software Requirements

Question 1

Requirements Engineering

Answer 1

Establishes:
- The services that the customer requires from the system
- The constraints under which the system operates and is developed.

Question 2

What is a requirement?

Answer 2

A requirement can range from a high-level abstract statement of a service/constraint to a detailed functional specification.

Question 3

Dual function of requirements

Answer 3

• May be the basis for a bid for a contract
• May be the basis for the contract itself

Question 4

User Requirements

Answer 4

Statements in natural language for the user to understand the services and the constraints.

Question 5

System Requirements

Answer 5

Sets out descriptions for the system services, which is wrote as a contract between client and contractor.

Question 6

Software Specification

Answer 6

Serve as a basis for a design or implementation (for developers).

Question 7

Functional Requirements

Answer 7

Says what the system does (provides statements of services).

Question 8

Non-functional Requirements

Answer 8

Constraints on the services or functions offered in the system.

Question 9

Domain Requirements

Answer 9

Reflects the domain’s impact on the software (if it is including large amounts of data for example, the domain would be under the data protection act.)

Question 10

Complete/Consistent

Answer 10

Requirements should be
Complete -> includes all descriptions of all facilities.
Consistent -> no conflicts or contradictions in the descriptions.

Question 11

Process Requirement

Answer 11

A “non-functional requirement” which states a programming language, or a CASE system, or a development method.

Question 12

Product Requirements

Answer 12

A non-functional classification which specifies that the product must behave a certain way.

Question 13

Organisational Requirements

Answer 13

A non-functional classification which specifies requirements which are a consequence of organisational policies and procedures which are non-external (programming language etc)

Question 14

External Requirements

Answer 14

A non-functional classification which specifies requirements which arise from factors which are external to the system and its development process.

Question 15

Performance Requirement

Answer 15

A potential non-functional classification which specifies the expected performance rate of a system.

Question 16

Verifiable Non-functional Requirement

Answer 16

A type of requirement which uses some measure that can be tested (for example, experienced controllers should be able to use all system functions after two hours of training, with the amount of errors being reduced to only 2 per day.)

Question 17

Requirements Measures

Answer 17

A table consisting of a property, and how that property is managed/measured.

Question 18

Issues with domain requirements

Answer 18

May be deemed unnecessary by user and therefore not tested (not stated on contract etc).

Question 19

Issues with user requirements

Answer 19

Lack of clarity (more clarity leads to complicated documentation) and requirement confusion (functional and non-functional requirements tend to be mixed-up in same document).

Question 20

Issues with non-functional requirements

Answer 20

Requirements have the potential to clash (username and password is easy to create, but the password must be complicated for security reasons).