When Automation Fails: The Art of Exploratory Testing

Automation is a powerful tool in a tester’s toolkit. It helps accelerate regression suites, enforce repeatability, and reduce manual effort. But automation is not a silver bullet. There are moments when it fails — when tests break, when edge cases slip through, or when a change in the product invalidates the automation assumptions. In those moments, exploratory testing becomes your secret weapon.

Why Automation Can Fail

Automation is great for stability, consistency, speed—but there are inherent limitations.

1. Brittleness due to UI changes or flakiness
   Automated UI tests often depend on locators, timing, or assumptions about page structure. When those change, tests break. Maintenance overhead creeps in.
2. Incomplete coverage of edge or unexpected flows
   Automation typically codifies “known” or expected flows. Rare corner cases, error conditions, multi-step paths are often missed.
3. False positives and false negatives
   Flaky tests may pass sometimes, fail at others—not because of bugs, but timing, environment, or state issues.
4. Cost of writing & maintaining tests vs payoff
   Not every path is worth automating; initial cost and ongoing maintenance cost often outweigh returns for seldom-run or unstable features.
5. Lack of human insight
   Automation cannot reason, question assumptions, detect usability issues, or explore the “unknown unknowns.”

When these failures happen, blindly expanding automation may not be the solution. That’s where exploratory testing shines.

What Is Exploratory Testing?

Exploratory testing is an approach where the tester actively designs and executes tests in parallel—learning the system, exploring its behavior, and discovering unintended behaviors. Instead of following a rigid script, exploratory testers adapt according to observations.

Key characteristics:

• Simultaneous learning, test design & execution
  You don’t pre-define everything, you adapt as you go.
• Adaptive & heuristic-driven
  You use heuristics, domain knowledge, user personas, risk factors to guide what to test.
• Feedback-oriented
  You observe system responses, ask “What if?” and probe suspicious states.
• Human judgment & creativity
  Testers bring intuition, patterns, curiosity—that’s something automation can’t replicate.

In short: a skilled tester, guided by curiosity and domain insight, actively seeks out what the automation cannot easily codify.

When Should You Lean on Exploratory Testing?

Not just “when automation fails”—exploratory testing should be a continuous companion. Some ideal moments include:

Exploratory testing gives you those last lines of defense before shipping.

Techniques & Strategies for Effective Exploratory Testing

To make exploratory testing fruitful (not aimless), some structure and discipline help. Here are tried-and-tested techniques:

1. Use Session-Based Test Management (SBTM)

• Break time into sessions (e.g. 60 or 90 minutes).
• Each session has a charter: a mission or test goal.
• At session end, produce a brief report: what was tested, findings, open questions, ideas for next session.

This adds accountability, focus, and traceability to exploratory efforts.

2. Define Charters / Goals

A charter might be:

• “Explore the shopping cart’s behavior when network disconnect occurs mid-checkout.”
• “Test password reset flows under various user states (activated, expired, locked).”

Charters keep you from wandering aimlessly.

3. Use Heuristics & Mnemonics

Heuristics help guide thinking. Some popular ones:

• CRUD — Create, Read, Update, Delete
• CRUD-LR — List, Read, Update, Delete, Link, Right
• FAR — Fail, Alter, Repeat
• RCRCRC — Repeat, Change, Repeat, Change…
• SFDIPOT — Structure, Function, Data, Interface, Performance, Operations, Time
• VISITED — Variation, Interaction, State, Timing, Error, Data

Pick a heuristic (or combination) to spur ideas. For example, using SFDIPOT, ask:

• Structure: Can I change layout, reorder elements?
• Function: What happens if I toggle a feature?
• Data: What about null, extreme, invalid data?
• Interface: How does it behave via API vs UI?
• Performance: What about slow network, high load?
• Operations: Are there race conditions or concurrency concerns?
• Time: What about sessions, expirations, scheduled jobs?

4. Exploratory Tours / Tag Tours

Take thematic “tours” through the application:

• Feature tour: Focus on a module (e.g. payments, user profiles).
• Data tour: Vary input datasets (valid, invalid, boundary).
• Workflow tour: Follow typical user journeys end-to-end.
• Crud tour: Operate on create/edit/delete cycles.
• Interrupt tour: Introduce interruptions — network lag, power off, switching tabs.

5. Risk & Prioritization Focus

You can’t explore everything. Use risk (business impact, likelihood) to drive what to test first. High-risk areas often yield valuable bugs.

6. Pair or Team Exploration

Pair testers, or include developers, product owners in exploratory sessions. Different perspectives often uncover issues others miss.

7. Logging, Note-taking & Tool Support

Capture what you do, what you observe, screenshots, logs, API traces. Tools like mind maps, exploratory test tools (e.g. Test & Feedback, Rapid Reporter, session recording tools) help.

8. Feedback Loops & Learning

After a session, reflect: What surprised me? Which assumptions failed? What new charters or tests arise? Use those to inform future sessions or automation.

Integrating Exploratory Testing & Automation: A Balanced Approach

You don’t have to choose one or the other—they complement each other.

• Use exploratory testing to identify stable flows to automate
  Run your exploratory sessions first, find what works reliably; then codify into repeatable tests.
• Reserve automation for regression, smoke, repetitive core flows
  Let automation handle the “bread and butter,” freeing testers to explore risky or novel areas.
• Run automated suites before exploratory sessions
  That way, exploratory time isn’t wasted hunting bugs already covered.
• Evolve automation from exploratory insights
  When a bug is found exploratorily, consider adding it as an automated test (if stable).
• Maintain feedback loop between both
  Failures in automation can hint at fragile areas worth exploring manually. Conversely, exploratory testing can uncover flakiness or edge cases that improve existing automatic suites.
• Use metrics wisely
  Track coverage of exploratory sessions, number of charters, bug density, test effectiveness (bugs per hour) vs time spent in maintenance of automation.

Common Pitfalls & How to Avoid Them

Here are some traps and how to steer clear:

Real-World Example (Illustrative)

Imagine you’re working on a mobile banking app. You have automation covering login flows, funds transfer, account statement pages. But after a release, a bug appears: when the user switches network from Wi-Fi to cellular mid-transaction, the app shows inconsistent balance or crashes.

• The automation suite didn’t cover network transitions (because it assumed stable connectivity).
• In an exploratory session, you charter: “Explore user balance and transactions under connectivity changes mid-flow.”
• You simulate disconnects, toggling Wi-Fi, throttling bandwidth, mid-checkout, mid-transfer, mid-session.
• You find that under certain timing, the transaction state is inconsistent, leaving duplicate or partial transactions.
• You log detailed reproduction steps, screenshots, logs.
• You also decide: this scenario should be added to automation—but only after stabilizing environment and designing robust waits.
• Meanwhile, developers fix the issue, you re-run the regression, and the next release is safer.

Without exploratory testing, this bug might slip to production, because it wasn’t anticipated in automation.

Tips for Getting Started

If you’re new to exploratory testing, here’s how to get your feet wet:

1. Set aside dedicated time
   Block 1–2 sessions (60–90 min) each sprint purely for exploratory testing.
2. Start small, pick one module
   Don’t try to do end-to-end at first. Explore one feature deeply.
3. Define charters & limit scope
   E.g. “Explore error handling in profile update API.”
4. Use heuristics & ask “What if?” continuously
   Challenge assumptions, vary inputs, break flows.
5. Record what you do
   Even simple bullet logs help. Use screenshots, video capture if possible.
6. Review & share findings
   Share with team, grab feedback, learn from each other’s exploratory sessions.
7. Grow gradually
   Over time, expand session lengths, rotate testers, build a library of charters.