In software testing, it’s crucial not only to ensure the quality of the product but also the quality of the testing process itself. This is assessed using QA metrics—indicators of test effectiveness, code coverage, and teamwork. One key metric is test coverage—the percentage of code or requirements covered by tests. QA professionals must stay flexible, assess project needs, and clearly communicate priorities to PMs. They should not blindly follow test plans or documentation; instead, they should apply critical thinking and common sense.
I recently attended a testing conference where the concept of the “Fast-Food Era of Testing—being overwhelmed by tests” caught my attention.
I want to share it with you because I completely agree with the speaker’s point: achieving 100% test coverage remains unachievable, so the task of QA is to strike a balance.
*Fast-Food” Testing: 100% Code Coverage ≠ 100% Bug Free Product *
There are some misconceptions about high test coverage, such as the assumption that it guarantees bug-free software. Blindly pursuing 100% test coverage can create more problems than it solves. Here’s how:
False Sense of Security:
Achieving 100% coverage may seem like a victory, but there may be hidden problems. Bugs often hide in areas that automated tests can’t predict, such as untested edge cases or real-world scenarios, because test coverage only shows how much of the app’s functionality is covered by tests, not how good those tests actually are.
Maintenance Cost:
More tests mean higher maintenance costs, as each test needs to be updated and managed regularly.
Diminishing Returns:
As you get closer to 100% coverage, it becomes harder to add meaningful tests. At some point, you’re just writing superficial, redundant tests to tick a box or boost metrics. You might even start writing tests that cover lines of code, but don’t test the actual functionality.
Opportunity Cost:
Time and resources spent on maintaining excessive tests could be better utilized elsewhere, such as improving tests quality or developing new features.
Business Risk:
Over-reliance on a large number of tests can introduce business risks, such as delayed releases or increased costs, impacting overall business performance.
The “Health” plan
To keep testing healthy, think of a balanced “meal plan” for QA:
H
— High-Value Focus
Focus on Minimum Viable Testing (MVT). Add only tests that bring clear business value.
E
— Eliminate Junk
Find and change flaky, remove duplicate, or low-value “fast-food” tests.
A
— Adopt Routines
Hold regular pruning sessions and refactor to keep the test suites clean and reliable.
L —
Level Coverage
Balance coverage at all levels—unit, integration, system. Give priority to high-risk, business-critical flows rather than chasing 100 % coverage.
T
— Track Relevance
Design tests with purpose. Continuously check if each test still aligns with current requirements and business needs.
H
— Healthy Mindset
Apply the 80/20 rule: 20% of well-designed tests often catch 80% of critical issues — so value quality over quantity.
