7.4Estimation Techniques

Accurate estimation of testing effort is a skill that improves with experience. Three techniques:

Work Breakdown Estimation

List every test type needed, estimate each:

Test Type	Estimated Time
Functional positive cases (12 cases)	3 hours
Functional negative cases (8 cases)	2 hours
Edge cases and boundary values	2 hours
Cross-browser testing (3 browsers)	1.5 hours
Exploratory session	1 hour
Bug verification and retesting	1 hour
Total	10.5 hours

Historical Analogy

"The last feature of similar complexity took 3 days of testing." This works best when your team tracks testing time per feature.

Keep a log:

• Feature X (medium complexity, API + UI): 2.5 days
• Feature Y (high complexity, third-party integration): 5 days
• Feature Z (low complexity, UI-only change): 0.5 days

Three-Point Estimation

(Optimistic + 4 x Most Likely + Pessimistic) / 6

Example:

• Optimistic: 2 days (everything goes smoothly, no blockers)
• Most Likely: 3 days (typical amount of issues and retesting)
• Pessimistic: 6 days (major bugs found, environment issues, scope creep)

Estimate = (2 + 4(3) + 6) / 6 = 3.3 days

This accounts for uncertainty better than a single-point estimate.