Effective Test Case Design: 5W2H Analysis and Common Design Techniques

Test case design is a fundamental skill for testers, yet many still encounter issues such as copying requirements directly, incomplete coverage, redundancy, unclear priorities, and low readability. This guide presents a systematic approach to overcome these problems.

5W2H Requirement Analysis – Before writing cases, analyze the requirement using the 5W2H method (Who, What, When, Where, Why, How, How much) to understand background, purpose, scope, and testing goals.

Case Structure – Plan a clear XMind hierarchy with first‑level modules representing functional areas (system‑level, page‑level, or business‑process level) and second‑level detailed cases. This prevents redundancy and improves readability.

Include auxiliary information in each case, such as requirement link, developers, core function notes, and tags.

Common functional modules (e.g., permission verification, shared components) should be isolated to avoid duplication across cases.

Prioritize core functions, highlight them for review and execution, and consider scenario‑based modules that link multiple features.

For large projects, create an independent smoke‑test module and record deployment steps, configuration, and schema to prevent omissions.

Design Techniques

1. Equivalence Class Partitioning – Divide input space into mutually exclusive classes (valid and invalid) and select representative values to reduce test count while maintaining coverage.

2. Boundary Value Analysis – Complement equivalence partitioning by testing values at, just above, and just below boundaries, as most defects occur at edges.

3. Scenario Flow Analysis – Map out business processes (basic, alternative, and exception flows) and design cases for each path to ensure complete coverage, especially for complex logic.

Example: Order placement – basic flow (login → add product → cart → checkout), alternative flow (checkout redirects to login), exception flow (login or order errors).

4. Error Guessing – Leverage experience and intuition to anticipate likely defects, supplementing other techniques when potential problem areas are not obvious.

In summary, by combining thorough requirement analysis, a well‑structured case hierarchy, and these design methods, testers can produce comprehensive, non‑redundant, and easily maintainable test suites that address functional coverage and software quality attributes.