system requirements (week 3)

Question 1

what are system requirements

Answer 1

list of features, functional, non-functional requirements and requisite use cases for the software

delves into how of a software

will be documented under the software requirement specification / functional requirement specification that will help developers understand the business and user requirements

Question 2

what are the types of system requiremetns

Answer 2

functional requirements
non functional requirements
domain requirements

Question 3

what are functional requirements

Answer 3

–> behaviours that the developed product should do or support

–> usually expressed as inputs into the product, outputs of the product, or a description of the behaviour itself

Question 4

give an example of functional requirements

Answer 4

authentication when the user tries to log into the system

system shutdown in case of a cyber attack

Question 5

what are non functional requirements

Answer 5

describe how a system must behave and establish constraints of its functionality (quality attributes)

define how the system must operate

system can meet its functional requirements and fail to meet its non functional requirements

Question 6

what are the software’s characteristics and expected ux

Answer 6

SPURS

security 
performance 
usability
reliability
scalability

Question 7

what is usability

Answer 7

defines how difficult it will be for the user to operate the system

Question 8

what are the 3 ways usability can be assessed

Answer 8

efficiency of use = avg time it takes the user to complete their goals, how many tasks can be completed, etc

intuitiveness = how simple it is to understand the interface and buttons

low perceived workload = how many attempts are needed by users to accomplish a particular task

Question 9

what is security

Answer 9

security requirements ensure that the system is protected from unauthorised access to the system and its data

considers different roles of authorization and authentication across different user roles

Question 10

example of security

Answer 10

access permissions from the particular system information may only be changed by the system’s data admin

Question 11

what is reliability

Answer 11

reliability decreases because of bugs in the code, hardware failures, or problems with other system components

Question 12

how to measure system reliability

Answer 12

count the percentage of operations that are completed correctly or track the avg period of time the system runs before failing

Question 13

example of reliability

Answer 13

database update process must roll back all related updates when any update fails.

Question 14

what is performance

Answer 14

performance is the quality attribute that describes the responsiveness of the system to various user interactions with it

poor performance will lead to a negative user experience

jeopardises the system safety when it is overloaded

Question 15

example of performance

Answer 15

front page load time must not be more than 2 seconds for users that access the website using an LTE mobile connection

Question 16

what is availability

Answer 16

it is the period of time that the systems operations are available for use with all operations

schedules maintenance periods directly influence this parameter

define the most critical components of the system that must be available at all time and prepare user notifications in case the system or one of its parts becomes unavailable

Question 17

example of availability

Answer 17

new module deployment must not impact the front page, product pages. The rest of the pages which experience problems must display a notification with a timer showing when the system is going to be up again

Question 18

what is scalability

Answer 18

describe how the system must grow

both hardware and software implications

Question 19

how to increase scalability

Answer 19

adding memory, servers, disk space, etc

compress data using optimising algorithms

Question 20

example of scalability

Answer 20

website concurent access limit must be scalable enough to support 500,000 users at a time

Question 21

name the 4 differences between functional and non functional requirements

Answer 21

–> functional requirements have detailed product features whereas non functional requirements have detailed product properties

–> functional requirements describe the work that is done whereas non functional requirements describe the character of the work

–> functional requirements describe the user actions whereas non functional requirements describe the user experience

–> functional requirements are characterised by verbs whereas non functional requirements are characterised by adjectives