Quality Engineering vs Quality Assurance: A Closer Look

Quality is critical for any software product. But how do you ensure it? Two approaches are commonly used – quality engineering (QE) and quality assurance (QA) At first glance, they may seem interchangeable However, when you dig deeper, there are some key differences between these methodologies.

In this article, we’ll examine quality engineering vs quality assurance in detail. We’ll look at what each entails, how they differ, and when you might use one vs the other. By the end, you’ll have a clear understanding of these distinct but complementary quality practices.

What is Quality Engineering?

Quality engineering refers to building quality into a product throughout its development lifecycle The goal is to prevent defects from occurring rather than finding them later through testing.

QE takes a process-focused approach. It aims to optimize the entire end-to-end process to deliver higher quality outputs. Key aspects include:

• Setting comprehensive quality goals upfront aligned to business objectives
• Defining metrics and guidelines for meeting quality goals
• Incorporating validation at every stage of development
• Using tools and automation to embed quality checks in workflows
• Enabling collaboration across teams on quality initiatives
• Continuous process analysis and improvement

What is Quality Assurance?

Quality assurance refers to the testing and evaluation activities implemented to detect defects in a product. The goal is to identify bugs, flaws, and gaps compared to requirements.

QA takes a programmatic approach. It executes a planned set of tests and assessments to validate quality. Typical QA techniques include:

• Functional testing – Verifying intended functionality works as expected
• Non-functional testing – Checking non-functional aspects like performance, security, usability
• Regression testing – Confirming existing functionality still works after changes
• User acceptance testing – Validating user workflows and needs are met
• Reviews and inspections – Manual examination to identify issues
• Defect tracking – Managing bugs through resolution and closure

In essence, QA provides concrete validation through rigorous testing and inspection. It complements QE by proving out quality empirically via executable tests.

Key Differences Between QE and QA

Now that we’ve defined QE and QA, let’s examine how they differ:

Timeframe

• QE spans the entire product lifecycle, from conception to launch and beyond
• QA focuses on the testing phase, typically towards the end of development

Scope

• QE considers all factors influencing quality – people, process, technology, tools
• QA is concerned with testing activities and defect detection

Focus

• QE is proactive, focused on prevention by building in quality
• QA is reactive, focused on finding bugs through testing

Ownership

• QE requires a cross-functional, collaborative approach
• QA is often owned by dedicated testing teams

Output

• QE produces improved processes and development frameworks
• QA generates executable tests, defect reports and metrics

QE vs QA: When Should You Use Each?

Now when should you emphasize QE versus QA?

Implement QE when:

• Starting a new product or feature development effort
• Quality issues are widespread and need a holistic solution
• Processes are inconsistent or opaque across teams
• There is lack of quality ownership across the organization

Prioritize QA when:

• Validating a production-ready product before launch
• Adding new functionality to an existing codebase
• Testing across platforms, devices, or user segments
• Deep focused validation is needed on a particular area

In practice, leverage both QE and QA together to cover quality comprehensively:

• QE to establish overarching quality framework
• QA to execute tactical testing within QE guidelines

QE Methodologies

Let’s look at some specific QE methodologies and concepts:

Continuous Quality

Continuous quality bakes validation into the development process. Testing is integrated into code checkins and builds. Issues surface faster through automation. Engineers get quality feedback in real-time.

Test Driven Development (TDD)

TDD requires writing tests before code. Developers create test cases, then write code to pass the tests. This validation-first approach leads to more modular, testable code.

DevSecOps

DevSecOps brings security into DevOps. It aims to shift security left by including security checks in pipelines. Tests also run in prod-like environments to catch issues earlier.

Lean QE

Lean QE applies lean principles like reducing waste and optimizing flow. The focus is eliminating non-value add quality activities so engineers can deliver faster.

QA Techniques and Testing Types

Some key QA techniques and testing types include:

Functional Testing – Validates intended functionality and requirements

• Unit testing – Isolates and tests individual code units
• Integration testing – Exercises interactions between components
• System testing – Evaluates the complete integrated system

Non-functional Testing – Evaluates non-functional requirements

• Performance testing – Stress tests the system under load
• Security testing – Identifies vulnerabilities or weaknesses
• Compatibility testing – Verifies operation across configurations

Acceptance Testing – Confirms the system meets user needs

• User acceptance testing (UAT) – End user workflow validation
• Alpha/beta testing – Live testing with a subset of users

Regression Testing – Checks existing functionality after changes

• Automated regression suites – Runs prerecorded test scripts
• Smoke testing – Broad sanity check of key functions

Reviews/Inspections – Examines work products manually

• Design/code reviews – Peer inspection to improve quality
• Walkthroughs – Step-by-step process validation

Implementing QE and QA

Here are some tips for implementing quality engineering and quality assurance:

• Define quality objectives upfront tied to business goals
• Create a quality plan outlining QE process and QA validation
• Incorporate quality ownership across teams
• Automate testing into continuous integration/deployment
• Establish quality metrics and leverage analytics
• Optimize testing for speed and coverage
• Foster collaboration between developers, testers, ops
• Continuously improve processes through feedback and reviews

Quality Engineering Certifications

Here are some popular certifications for quality engineering skills:

• ASQ Certified Quality Engineer (CQE)
• ISTQB Certified Test Engineer
• Scrum.org Professional Scrum Developer (PSD)
• Scaled Agile Framework (SAFe) DevOps Practitioner

These certifications validate expertise in quality processes, testing, agile development, and DevOps. They are valued credentials for QE and QA professionals.

Quality engineering and quality assurance provide complementary approaches to building great software. QE establishes an organizational framework while QA executes tactical testing. Leading organizations leverage both methodologies together to validate quality across the product lifecycle. By mastering QE and QA, development teams can deliver higher quality, more reliable products.