Non-Functional Requirements

Overview

Detailed Description

Some points are empty since no non-functional-requirements have been identified yet for these categories. They are marked with the abbreviation TBD. which stands for “To Be Defined”. The titles were left in on purpose to simplify the extensibility of this document.

Functional Suitability

Completeness

TBD.

Correctness

Title (ID)	Functional Correctness
Scenario	A user wants to perform a certain action.
Stimulus	Black Fennec handles the action as expected.
Expectation	Black Fennec provides the correct results with the needed degree of precision.
Measure	Gitlab pipeline does not allow failing test cases. Merge Assignee/Reviewer checks for coverage featured in merge request.
Criteria	At least 90% of the code has to be covered by unit tests which are successful..

Appropriateness

TBD.

Reliability

Maturity

Good Documentation

Title (ID)	Interface Documentation
Scenario	Developer wants to lookup something in the Documentation.
Stimulus	The Developer does not understand how two components interact with each other.
Expectation	Both components and their interaction, if any, can be found in the documentation.
Measure	Merge requests are checked for sufficient documentation of added functionality.
Criteria	Interfaces and classes important to an external developer are documented.

Well Tested

Title (ID)	Unit-Testing
Scenario	A new feature for the application is required.
Stimulus	Developer adds new source code to the project.
Expectation	Code coverage does not decrease significantly. The goal of the new feature is tested on fulfillment. Unit-tests cover equivalence classes and boundaries.
Measure	Merge Request with Assignee and Reviewer prevent code to be merged without Testing.
Criteria	Test coverage above 90 %.

Title (ID)	Regression-Testing
Scenario	A preexistent feature for the application has to be changed.
Stimulus	Developer changes source code of the project.
Expectation	The goal of the feature adaptation is tested on fulfillment. Old usage of the code keeps working as expected. Errors that were fixed before are not reintroduced.
Measure	When bugs are fixed a new testcase has to be created. A CI/CD pipeline test commited code on quality measures and runs the unit-tests of the project.
Criteria	All unit-tests succeed.

Completeness

Title (ID)	Requirements-Fulfillment
Scenario	The Application is used by the client (Team/PO).
Stimulus	A demonstration before the release in the productive environment is done.
Expectation	No unexpected exceptions happen when using the final product. All NFRs required for a successful usage of the application are fulfilled.
Measure	System tests try to measure the fulfillment of functional and non-functional-requirements.
Criteria	Each Requirement if feasible and untested with unit-test is featured in the system-testing protocol to test its fulfillment.

Availability

Internet Dependence

Title (ID)	Internet-Dependence
Scenario	A user is using the application.
Stimulus	The device used by the user looses connection to the internet.
Expectation	Changes that require to be synchronized to a remote platform can be saved locally and later explicitly uploaded to a shared resource.
Measure	File-sharing is done using git, which comes with capabilities to ensure offline saving and distribution of files in dedicated moments.
Criteria	Any feature requiring internet connection provides offline alternative or meaningful error message.

Fault Tolerance

Handling Exceptions

Title (ID)	Exception-Handling
Scenario	A user is using the application.
Stimulus	An exception is thrown.
Expectation	The application keeps running. The user is displayed a meaningful error message. The exception is logged, and allow to draw conclusions on why the error happened.
Measure	In code review of merge requests exceptions are looked at to ensure sufficient logging is done.
Criteria	Any exception is captured on application level and printed in a dedicated window.

Recoverability

Title (ID)	Malformed-Configuration
Scenario	A user opens the application.
Stimulus	invalid configuration or invalid module causes a software failure.
Expectation	The application can be started even if the configuration file is malformed.
Measure	A recovery mode (no extensions loaded) allows the loading of valid files which can be parsed, edited and analysed.
Criteria	Application starts despite malformed config.

Performance Efficiency

Time Behaviour

Fast Starter

Title (ID)	Application-Start
Scenario	A user wants to work with the application.
Stimulus	A user opens the application.
Expectation	A loading screen shows the status of the application to the user. As soon as the preparatory tasks are done, the main window opens.
Measure	First operation is showing the loading screen which is capable of showing the status of the operation in progress.
Criteria	The application/loading screen starts within 500ms of clicking the icon on a consumer laptop (intel i5 8th gen + 8gb ram) IF no additional extensions are installed.

Loading Projects

Title (ID)	Project-Loading
Scenario	A user wants to enter data or visualise a file.
Stimulus	A file is loaded by the user.
Expectation	The file opens and the data is displayed in the first meaningful view.
Measure	Only first meaningful view displayed, succeeding operations done afterwards.
Criteria	With a medium sized file (500 MB) it should take no more than 800ms if the reference implementation of the presenter is used.

Quick Save

Title (ID)	Project-Saving
Scenario	A user wants to save the changes made to a file locally.
Stimulus	The user triggers the save option.
Expectation	The changed data is saved into the currently open file.
Measure	Efficient JSON serialisation with dedicated library.
Criteria	Saving a medium sized project with X (TBA) changes takes no longer than 3000ms.

Flash Decision

Title (ID)	Type-Selection
Scenario	A user has data that can be interpreted in multiple ways.
Stimulus	The user selects a type for the visualised data.
Expectation	The visualisation changes to show the selected type.
Measure	Evt. lazy loading to improve performance.
Criteria	With a core data-type it should take no more than 150ms. More advanced types such as lists take no more than 300ms. Extension types are out of scope.

Resource Utilisation

TBD.

Capacity

Heavy Lifter

Title (ID)	Project-Loading-Limits
Scenario	A user wants to enter data or visualise a file of large extent.
Stimulus	A large file is loaded by the user.
Expectation	The file opens and the data is displayed in the first meaningful view.
Measure	Large operations done after showing the first meaningful view. A loading screen also counts as meaningful view.
Criteria	With a large sized file (1 MB) it should be possible to open it in 1000ms if the reference implementation of the presenter is used.

Compatibility

Co-existence

Git Integration

Title (ID)	Git-Integration
Scenario	A user wants share files with other users.
Stimulus	The user prefers the git console over the git-integration in the application and uses it.
Expectation	The application detects changes to its working directory and adjusts relevant data.
Measure	The file system is watched by the application for changes out of scope and copes with them.
Criteria	Changed branches, pulling and conflicts are recognized.
Out of Scope	True

Json as a Service

Title (ID)	Project-Export
Scenario	A user wants to export his project to share with another user including all his settings.
Stimulus	The user exports the project on a certain level (underlay/overlay).
Expectation	The project is exported including all settings of the user.
Measure	Mechanism to create interpretation of project data into exported file. Save Black Fennec version to project file, to allow conversion to newer format.
Criteria	Setting of user compatible with version of importing application are respected.

Title (ID)	Project-Import
Scenario	A user wants to import a project file another user gave him.
Stimulus	The user imports external project.
Expectation	The settings of the project exported are kept in the imported project
Measure	Mechanism to interpret imported project data.
Criteria	Setting of exported project compatible with version of importing application are respected.

Interoperability

Work in External Structure

Title (ID)	No-Project-Context
Scenario	A user wants view/edit file in external directory.
Stimulus	The user opens JSON file with Black Fennec.
Expectation	The file is interpreted and visualised without requiring a project context.
Measure	No dependence on project settings. Check for sufficient rights, understandable error message shown if no permission.
Criteria	Original file is opened if permissions allow. Changes in file can be saved if permissions allow.

Work with files of External Structure

Title (ID)	Json-Import
Scenario	A user wants share files with other users that are encapsulated in directory used by others.
Stimulus	The user imports external json into project.
Expectation	The original file location is saved. The file is copied into the project.
Measure	Check for sufficient rights, understandable error message shown if no permission.
Criteria	Original file is not changed.

Title (ID)	Json-Export
Scenario	A user wants to export a file in his project to an external location.
Stimulus	The user clicks to export a file of the project.
Expectation	The file is exported without containing any Black Fennec proprietary data.
Measure	Check for sufficient rights, understandable error message shown if no permission.
Criteria	File at location is overwritten. No proprietary data contained in exported file.

Usability

Appropriateness

Data Aggregation

Title (ID)	Data-Aggregation
Scenario	A user wants to aggregate data from several sources into one file.
Stimulus	The user open a new project and inputs external data.
Expectation	The application allows the user an efficient workflow for aggregation of data.
Measure	Dedicated presenters for different use cases to allow optimized workflows.
Criteria	The most important functions are maximum two clicks away.

Data Visualisation

Title (ID)	Data-Visualisation
Scenario	A user wants to look at interconnected data.
Stimulus	The user opens a file containing interconnected data.
Expectation	The application shows an overviewable visualisation of interconnected data.
Measure	Dedicated presenter for visualisation of interconnected data (graph).
Criteria	interconnection of data visualised with lines in between data.
Out of Scope	True

Learnability

Just Like an Apple

Title (ID)	Intuitive-Application
Scenario	A user wants to work with Black Fennec.
Stimulus	The user opens the application for the first time.
Expectation	The user can operate basic use cases after few minutes of using the application.
Measure	Walk-through upon first opening of application. Manual for usage of application.
Criteria	Closed-card-sort and tree-sort passed with industry standards.

Operability

TBD.

User Error Protection

Better than Hawaii

Title (ID)	Confirmation
Scenario	A user wants to perform a critical operation.
Stimulus	The user clicks to perform a critical operation.
Expectation	The user is asked whether he is not accidentally click said action.
Measure	Show confirmation dialog before executing critical operation.
Criteria	Confirmation dialog before performing critical actions.

Title (ID)	Reversion
Scenario	A user wants to perform a critical operation.
Stimulus	The user clicks to perform a critical operation.
Expectation	The user is able to undo the critical action for a specified amount of time.
Measure	Save previous state of application to rollback.
Criteria	Critical actions can be roll-backed for at least 1m if possible.

User Interface Aesthetics

TBD.

Accessibility

Stolze Spezial

Title (ID)	Screen-Reader-Support
Scenario	A user wants to understand the interface without seeing it.
Stimulus	A user triggers the screen reading function.
Expectation	The screen reader understands the software interface and can translate text into speech.
Measure	All main functionalities are equipped with the text to speech “tag”.
Criteria	System Test with impaired person succeeds.
Out of Scope	True

Title (ID)	Color-Blind-Support
Scenario	A user wants to understand any clickable action despite his color-blindness.
Stimulus	A color blind user uses Black Fennec.
Expectation	Clickable actions are distinguishable besides their color. 2-Senses principle.
Measure	2-Senses principle adhered in UI design.
Criteria	Black-and-White Test of the application.
Out of Scope	True

Title (ID)	Easy-to-Read
Scenario	A user wants to understand the interface despite minor visual impairment
Stimulus	A user with minor visual impairment uses Black Fennec.
Expectation	If the font size is to small to see, it can be resized. Contrast of colors make it easy to read text.
Measure	AA-Rating in color contrast. Resizable font size, and responsive design to cope with big text.
Criteria	Font size customizable. Color Palette checked for AA-Rating.
Out of Scope	True

Security

The security section is not filled with many NFRs because the assessment of these NFRs is done via Threat-analysis and Attack-Trees.

Confidentiality

Sand Box

Title (ID)	Application-Isolation
Scenario	A user imports malicious data into Black Fennec.
Stimulus	The Malicious code is executed inside the Black Fennec tool.
Expectation	The malicious data doesn’t affect the OS.
Measure	Application can be executed in isolated environment.
Criteria	Application is sand boxed.
Out of Scope	True

Integrity

TBD.

Non-repudiation

TBD.

Authenticity

TBD.

Accountability

TBD.

Maintainability

Modularity

Title (ID)	Extension-System
Scenario	A Developer wants to develop additional feature.
Stimulus	Additional feature required.
Expectation	Easily usable interface to extend functionality of Black Fennec.
Measure	Extension Manager providing extension API which allow for extensions.
Criteria	Possibility to extend functionality exists.

Reusability

TBD.

Analyzability

TBD.

Modifiability

Windows is Broken. Long live Windows

Title (ID)	Clean Code
Scenario	A Developer develops low quality code for the sake of time.
Stimulus	The general code quality decreases.
Expectation	Developers pay attention to clean code and broken widows in development
Measure	Code will be reviewed before every merge.
Criteria	Can be measured using pylint.

Testability

Title (ID)	Dependency-Injection
Scenario	Developer has to test component to achieve sufficient coverage.
Stimulus	Developer tests code.
Expectation	The code written by the developer allows for easy testing by mocking component.
Measure	Components are linked through dependency injection.
Criteria	90% test coverage is maintained.

Portability

Adaptability

Title (ID)	Python-Compatibility
Scenario	A user wants to install Black Fennec
Stimulus	User executes Black Fennec
Expectation	The program runs independent of the OS. Any system with python installed can run Black Fennec
Measure	Application written in Python
Criteria	Application runs on python

Installability

Title (ID)	Black Fennec-Installation
Scenario	A user wants to install Black Fennec via the command line.
Stimulus	The user executes the pip install… command.
Expectation	The user can install the tool using the pip install command.
Measure	The user can start the Black Fennec Tool via the desktop icon.
Criteria	Application installable via pip CLI.

Replaceability

Hail JSON

Title (ID)	No-Black-Fennec
Scenario	The user wants to read files created with Black Fennec without Black Fennec.
Stimulus	Black Fennec file opened with plain text editor.
Expectation	The file produced by Black Fennec is readable to the user. Saved data unpolluted with internal states, overviewability of JSON kept.
Measure	All data is saved as JSON and therefore is easily readable.
Criteria	Files created with Black Fennec are JSON.