How to write an effective test coverage plan

John Gluck
July 8, 2025

Too often, the teams assigned to build test coverage jump in without a clear plan or vision. Instead of a strategy and roadmap, coverage plan priorities are determined by which object shines the brightest or which product owner shouts the loudest. But without a system for surfacing what should be covered and why, test suites end up with gaps in coverage that slow down feedback loops.

A comprehensive test coverage plan outlines what your app does, identifies the behaviors that matter most, and determines which aspects need to be tested automatically versus manually. It’s not a spec, it's a roadmap for quickly establishing real coverage, without spending weeks in planning mode.

QA Wolf utilizes this five-step process when creating coverage plans. It’s designed to build functional, durable tests fast, even if your team is starting from zero. 

Step #0: Define what’s worth testing

Before you map workflows or write a single test case, you need to decide what you’re trying to cover—and why. Most teams will use one of these models, although they may not formally employ them. Rather, they use their intuition, informed by their knowledge of the product, to determine which test scenarios will contribute to the overall meaning and value of their coverage.   

  • Workflow or path coverage: Follows a user’s path through the product, focusing on how the application behaves as state changes over time. It’s especially useful for catching issues that appear when the app interacts with third-party systems.
  • Functionality or product coverage: Examines input/output combinations within the UI to make sure the system behaves correctly across different states. This model helps identify where the application may have coverage gaps.
  • Requirements coverage: Maps tests directly to product and business expectations, both implicit and explicit. It helps ensure you’re meeting stakeholder commitments and building the features users actually need.
  • Risk coverage: Ranks test cases by the potential damage a failure could cause. It drives focus toward critical paths, high-severity edge cases, and parts of the application that are either frequently broken or hard to fix after the fact.

These models overlap by design. No single one is enough on its own, but together they offer a more balanced view of your product’s health. Some teams also layer in other dimensions like revenue impact, compliance requirements, or recency of change to further refine their priorities.

Step #1: Break your product into testable workflows

A workflow is a self-contained sequence of user actions that completes a distinct task. Each one should be independently runnable and start from a clean slate. If you have to reset or configure the app in a special way to test a path, that path should be a separate workflow.

These constraints aren’t arbitrary. They reflect how QA Wolf maintains thousands of tests across dozens of apps without duplicating effort or introducing instability. The more you define workflows this way from the start, the less you’ll spend maintaining brittle, interdependent tests later.

Use these five rules to define workflows:

  1. Clear start and end states: A workflow should begin from a known state (e.g., logged out, fresh session) and end in a verifiable outcome (e.g., a confirmation screen, an updated dashboard, or an error message).
  2. One primary goal per workflow: Avoid scope creep. "Checkout with promo code" is a separate workflow from "Checkout with PayPal."
  3. Minimal internal branching: A workflow should stay focused on a single user goal. If a test path requires stepping away from the goal—such as editing a profile during a checkout flow—test that in a separate workflow.
  4. Reusable setup: Group test cases that share setup (auth state, seeded data). If the setup diverges significantly, split the workflow.
  5. Deterministic execution: Flows should run reliably across environments. Flag any path that relies on non-deterministic behavior, static data, or third-party availability.

Some example workflows:

  • "Log in from the homepage."
  • "Reset password via email link."
  • "Publish a new post."
  • "Purchase item with saved credit card."

These often map to user stories, feature flags, or product epics. Start broad, then refine. Group by feature set, navigational area, or customer intent—whatever best reflects how your teams deliver work.

Track workflows in a format that integrates with test planning and CI visibility—Git markdown files, a TestRail tree, or QA Wolf’s test graph all work. Prioritize visibility over tooling preference.

Step #2: Prioritize workflows by what matters most

You don’t need to test everything at once. Focus on workflows that are critical to your customers and business. These are the ones that break production, block releases, or drive support tickets when they fail.

Tag each workflow with a priority:

  • Automate now: High-risk, high-usage, or high-friction workflows.
  • Backlog for later: Still worth covering, but not urgent.
  • Manual only: Either not worth automating or not possible to automate.

We use a few simple questions to help teams make the call:

  • How often is this used?
  • What happens if it breaks?
  • Is it part of a critical path (signup, checkout, login)?
  • Is it new code or known to break often?

Don’t skip workflows that are manual-only—just make sure your team tracks them. You want complete visibility, even if some gaps are intentional.

​​Think of your coverage plan as a funnel: your team starts broad by mapping all workflows, then narrows its focus as it prioritizes and outlines specific behaviors. Front-load the top-priority workflows; the rest can be developed just-in-time, triggered by new features, bug reports, or repeat incidents. This lets you scale coverage as needed without wasting effort on low-risk paths too early.

Step #3: Write one test case per behavior

Now that you've defined workflows, it's time to break them down into individual test cases. Each test case should cover one discrete behavior or decision point within the workflow.

That means:

  • Every test case should validate a single outcome.
  • Test cases should be runnable independently, without relying on previous test steps.
  • Naming should be specific enough to describe precisely what scenario or behavior the test validates.

Good examples:

  • "Login with valid credentials."
  • "Reject login with wrong password."
  • "Create a draft post with a missing title."

Bad examples:

  • "Login with good and bad credentials" (this combines two test paths into one)
  • "Verify login functionality" (too vague—this could be several things, and we don’t know which?)

If you're unsure where to draw the line between one test and the next, start by writing one test for each validation rule, user action, or possible error condition. You can always consolidate later if some cases prove redundant.

Work in batches. Outline 10–20% of your test cases at a time so they stay aligned with product changes and don't go stale.

Step #4: Write outlines that are easy to turn into code

Outlines are the handoff between planning and automation. At QA Wolf, we follow the Arrange–Act–Assert (AAA) structure. Write out each test case outline as a comment block that includes:

  • Arrange: Prepare the environment. This might include setup steps (such as creating users or data), cleanup logic, or any functionality already validated in other tests.
  • Act: The direct user interaction under test—clicks, form fills, submissions, navigation.
  • Assert: The expected outcome. It could be a UI message, a redirect, or a change in database state.

Use consistent language for actions and UI elements. Your goal is to create an outline that is both readable and immediately implementable by anyone on the team.

// Test: Login with wrong password
// Arrange: Create user in database
// Arrange: Go to login page, fill in form with correct email and wrong password
// Act: Submit
// Assert: Show error message, stay on login page

Step #5: Review and maintain your plan

Don’t treat your coverage plan as a one-and-done. It should evolve with the app. Review it every quarter with product and engineering:

  • Are your priorities still right?
  • Are new features tested?
  • Are old tests still valuable?
  • Do manual-only areas need revisiting?

A good coverage plan keeps your tests useful and your team focused

Test automation only works if you’re testing the right things, the right way. A clear, actionable coverage plan gives your team the structure to do exactly that. It turns instinct into alignment, guesswork into repeatability, and scattered effort into high-impact testing.

When you define workflows upfront, prioritize by risk, and structure test cases around specific behaviors, your team avoids writing brittle tests and chasing edge cases that don’t matter. And when you treat the plan as a living artifact—updated with every release, incident, or roadmap shift—you keep coverage aligned with the customer experience.

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