Lecture Flashcards
Quality
Refers to the degree a software product meets specified requirements
Software requirements
Functional: what does the system do
NonFunctional: how the system performs is functions
(unibility,performance, reliability, security)
Quality metrics
Quality metrics provide a basis for consistent unbiased evaluation and support continuous improvement
Why early definition of quality
Avoid cost overuns and delays
Aligns stakeholder expectations
Facilitates objective judgement regarding Quality Achievement
How to define Quality in a project
Start with requirements
use measurable metrics to track quality
e.g. performance response time
or defect limits less than 10 defects per line of code
or user satisfactory score
What steps in stepwise are quality related:
1234 and 8
Importance of software quality management
The critical role is growing rapidly
the size and complexity of software is increasing
software products are increasigly including third part components or using online services
Risks: failers secuity vulnerabilities and integration challenges
Product quality management
Quality control, evaluation of the final product against requirements
Goal is to deliver a product that meets defined Quality requirements
Process quality management
Quality Assurance, evaluation of the process behind product development
goal” build quality into the product from the start, minimising the chances of defects later”
Process quality management
the purpose is to ensure that the project conforms to the mutually agreed requirements, specifications and expectations:
CMMI,
Six Sigma
Agile and DevOps perspectives:
Agile quality management is Agile testing Quadrants
DevOps Quality management is Continuous integration/ continuous delivery
External Quality Characteristics
External Characteristcs reflect users view of the software
Internal Quality characteristics
Internal Characteristics reflects the developers viewpoint, e.g.
how well…
structured, modular or documented it is
Directly measured characterisitics
Directly measured characteristics map measurements to requirements, e.g.
mean time between failures must be less than a given upper bound.
Indirectly measured characteristics
indirectly measured characteristics are ascertained from measurements. number of user inquiries received by help desks is an indirect indicator of the software usability
What are direct and indirect measured quality characteristics used for?
meet user experience and code is of high quality for user
What is Quality management Plan
Outlines how quality will be managed throughout the project and ensure that the plan covers all quality processes and activities.
Quality Plan: what is Quality Objectives
A shared view with project team and stakeholders
the purpose of this section is to align team and stakeholders on what we want to achieve, set expectations
Quality Plan: what is Quality Process
a framework that will be used to ensure quality
Auditing
functionality review
coding review etc
Quality Plan: what is Quality Characteristics
Needs to be specified
specific attributes of software that will define software
functional and non-functional requirements needs to be specified
Quality Plan: what is Quality Metrics
needs to be defined to measure quality characteristics
able to measure to see if we have
achieved our goals.
measures quality characteristics
e.g.defects per 1000 SLOC
Quality Plan: what is Quality Roles and responsibilities
team members accountable for each step/taskin the quality management plan
Clearly assign team members for each management task
ensure accountability and promote collaboration for team to work together
what is Quality specification
more focused more detailed for quality of product
What does the Quality specification include?
-Definition description
-scale
-test
-minimally excepted value
-target range
Quality specification: definition and description
of the Quality Characteristic.
Detailing the characteristic, more throurough description and detail.
Specifying what is happening e.g. speed
Quality specification: Scale
the unit of measurement,
what we will be measuring during the Activity
Quality specification: Test
the practical test can be used to assess the extent to which the quality characteristic is present in the software product
Quality specification: Minimally accepted value
the worst value that would be acceptable and below this, would have to be rejected
measuring response time, metric must not exceed 5 seconds
or search quesry on ecommerce platform, degrades user experience.
Quality specification: Target Range
the range of values within which the quality measurement is planned to lie
set a target range, where the quality metric should fall,
Measurement of quality characteristic: Availability
ther percentage of a pre specified time interval that the system is operational
Measurement of quality characteristic: failure rate
the probability that a transaction e.g. loading a web age… will fail
Measurement of quality characteristic: Mean time between failures (MTBF)
The average time that a system that operated between failures calculated as the total operational time, devided by the number of failures that occurred during that period
