Mastering Complex Design Requirements with an Add‑Subtract Method

1. Understanding Requirements

Designers should first grasp the background, user roles, and product logic of a requirement. For an internal permission‑allocation platform, this involves recognizing the complexity of permission logic and gathering insights from product teams, users, and existing resources such as the "100 Solutions for Role‑Based Permissions" article.

2. Structuring Requirements

Transform scattered requirement notes into a structured format. Identify user roles (e.g., super admin, business admin, HR), target objects (departments, positions, personnel, permission bundles), and possible actions (CRUD and association). Create a relationship matrix that clarifies how objects interact, such as departments containing positions, personnel belonging to departments and positions, and permission bundles being assignable to departments or positions.

These structured tables reveal hidden functional gaps that can be addressed early.

3. Design Subtraction: Focus on the Core Flow

Prioritize framework design before detailing UI elements.

Complete the main workflow first, then consider exception scenarios.

Map each module from the functional matrix to independent screens, adding shortcut actions later.

Document edge cases for later refinement.

4. Design Addition: Consider Edge Cases

After the core flow is solid, revisit the design with a user‑centric perspective to capture special scenarios such as personnel changes, high‑level executives holding multiple roles, outsourced staff without department affiliation, and frequent personnel turnover. Propose solutions like automatic synchronization with OA systems, red‑dot pending tasks, additional position‑removal features, and a searchable interface for quick personnel actions.

Iteratively scan the entire workflow to identify and address these additional needs.

5. Summary

The add‑subtract design method consists of four major steps: (1) discover and understand the problem from real scenarios, (2) structure requirements into a functional mapping table, (3) apply design subtraction to solve the core problem first, and (4) apply design addition to cover comprehensive edge cases. Combining rational analysis with empathetic user insight leads to a clear, efficient, and user‑friendly design.