As an experienced quality assurance architect with over 10 years of expertise testing complex web and mobile applications, I often get asked – "What exactly should testers validate before an application can safely be released to users?"
This is an excellent question, because the quality and reliability of the end user experience depends directly on the scope and depth of testing. In this detailed guide, I‘ll provide a complete overview of the key areas testers need to verify, with actionable checklists and recommendations that teams can directly build into their processes.
We‘ll specifically be focusing on two crucial categories:
Functional testing – validating that core features and components work as expected
Non-functional testing – assessing broader quality attributes like usability, security and performance
Let‘s start by examining both areas more closely…
An Introduction to Functional and Non-functional Testing
Think of functional testing as checking that an application works as designed – its key functions operate correctly and deliver their value as promised.
For example:
- Users can sign up for new accounts
- Transactions process properly end-to-end
- Search results match what was queried
- Admins have access to content management tools
The focus is purely on verifying the step-by-step logic and outcomes across user journeys.
Non-functional testing takes a wider lens, assessing how well those user journeys happen. Instead of functions, it evaluates quality attributes like:
- Usability – How easy and intuitive is the UX?
- Performance – Does the app respond quickly under load?
- Security – Are there vulnerabilities open to exploitation?
- Accessibility – Can users of all abilities use the system?
So while functional testing focuses on correctness of features, non-functional testing concentrates on the relative quality of the overall user experience. Both are crucial, and testers utilize a combination of automated checks and manual testing to thoroughly validate both areas.
Now let‘s explore comprehensive checklists across both…
The Functional Testing Checklist
Robust functional testing requires methodically validating every user flow from start to finish across the application‘s key areas.
Based on industry standards and my expert experience architecting QA processes for top Silicon Valley brands, this is the functional testing checklist I would recommend:
User Account Creation
- [ ] Validate all form fields and data validation
- [ ] Check error handling across input combinations
- [ ] Confirm new user data storing/transmission over SSL
- [ ] Verify confirmation emails with sign up links
Login / Logout
- [ ] Test login success across accounts
- [ ] Validate handling of invalid username/passwords
- [ ] Check session persisted with "Remember Me"
- [ ] Confirm logout clears all session data
Profile / Settings
- [ ] Test CRUD operations across user profile schema
- [ ] Upload profile images to validate handling
- [ ] Verify API integrations read/write properly
Navigation / Menu
- [ ] Check navigation links route to proper pages
- [ ] Confirm responsive menu adaptations
- [ ] Validate in-page anchors connect to right sections
Search / Filtering
- [ ] Validate matching and weighted search results
- [ ] Test filters narrow result sets properly
- [ ] Confirm pagination through large data sets
- [ ] Validate ‘no results‘ error case handling
Transactions / Payments
- [ ] Verify transaction life cycle across payment types
- [ ] Check input validation and error handling
- [ ] Confirm order histories/receipts populate properly
- [ ] Test refund/cancellation flows
Admin Access
- [ ] Validate role-based access across tools
- [ ] Check CRUD permissions align to roles
- [ ] Confirm auditing captures access attempts
Multi-Language Support
- [ ] Verify UI translations match specs
- [ ] Check layout adapts correctly to translations
- [ ] Confirm regional currency/date formats displayed properly
Private/Protected Access
- [ ] Confirm pages/features hidden from public access
- [ ] Validate admin-only dashboards secured properly
Integrations
- [ ] Verify connectivity across integrated tools
- [ ] Check payloads handle malformed responses
- [ ] Confirm UI updates match API data
SEO / Meta Data
- [ ] Validate page title tags and meta descriptions
- [ ] Check resource loading elements for SEO
Error Handling
- [ ] Force system faults to validate messaging
- [ ] Check invalid page routes resolve properly
Plus whatever powerful features make your product unique! The key is methodically validating every possibility across the entire user journey lifecycle.
Automated Testing Capabilities
Executing testing this exhaustive requires balancing manual real-world usage with automated checks for system fault injection, cross-browser validation, and repetitive tasks.
The most robust way to enable this is leverage a SaaS testing platform that allows running pre-scripted tests in parallel across thousands of real browsers and devices via the cloud. Engineers can code re-usable test scripts with frameworks like Selenium or Appium once, then execute them on-demand without needing to set up complex device labs.
BrowserStack and SauceLabs lead in providing these capabilities, combined with debugging tools for detailed results analysis. The time and cost savings over manual testing and in-house labs are substantial.
Evaluating Quality: The Non-Functional Test Checklist
Now that we‘ve validated whether key user journeys work via functional testing, the next imperative is assessing how well they work. This means putting the application through a gauntlet of non-functional test types to surface any lurking experience defects:
Usability Testing
- Plan out tasks mapped to primary user goals
- Recruit 5+ users representing personas
- Quantify task pass/fail rates
- Identify pain points/friction areas
Accessibility Testing
- Audit against WCAG 2.1 compliance
- Validate keyboard/screen reader navigation
- Check color contrast ratios
- Confirm ARIA landmark tags
Performance Testing
- Test load times across networks/devices
- Trigger performance budgets
- Check site stability under traffic spikes
Security Testing
- Execute authn/authz tests
- Attempt malicious injections
- Perform software composition analysis
- Validate encryption for data
Compatibility Testing
- Execute on macOS/Windows versions
- Test latest iOS/Android releases
- Validate across browser versions
Compliance Testing
- Catalog regional regulatory requirements
- Outline technical controls needed
- Maintain validation evidence
Production Issue Replication
- Analyze past crash logs for patterns
- Reproduce crashes/defects locally
- Confirm existing fixes remain sound
Expert Tips for High-Impact Testing Process Improvement
Evolving any test practice requires weighing costs versus risk reduction – maximizing coverage while minimizing execution overhead.
Here are a few key lessons from my time architecting testing programs:
Combine Automation with Exploratory Testing
Automated checks are great for quickly validating determinsitic items like UI rendering. But nothing replaces human intuition for finding edge cases via open exploration. Use both manual poking and scripted tests in tandem across all test types.
Test Early, Test Often
The earlier a defect can be detected, the less costly it is to rectify downstream. Start validating across environments from initial component availability rather than just before launch.
Utilize Flagship Devices
While simulators have improved, nothing replicates real mobile hardware behavior better than physical phones and tablets – especially leading models. Invest in keeping a select inventory of flagship units from Apple, Samsung and Google for hands-on access.
Define Exit Gates Around Risk
Not all defects pose equal risks. Categorize finds into risk severity levels, and create go/no-go gates tailored to your comfort around what can remain pre-launch versus what must be fixed.
Revisit Test Strategy Regularly
Review process gaps during post-mortems. Over time evolution leads to divergence between documentation and actual execution. Revalidate strategy fit to close any holes that emerge with each release.
Testing thoroughly across the functional and non-functional realms takes considerable coordination, but pays back exponentially in customer satisfaction over the long run. Use this guide as a starting point for maximizing what your team validates at each stage to drive quality upstream.
Now go unleash those test plans! Here‘s to crashing bugs, not launches 🚀
