WBS: task decomposition

简介 / Introduction

WBS (Work Breakdown Structure) is a standard method for decomposing a project into smaller, manageable work units. This article covers how to draw WBS diagrams using both PlantUML and Mermaid — both have clean, readable syntax ideal for project planning and documentation.

PlantUML 版

PlantUML supports WBS via the wbs diagram type, using indentation and + prefixes to denote hierarchy levels:

@startwbs
+ Project Planning
++ Requirements Analysis
+++ User Interviews
+++ Competitor Research
++ Project Planning
+++ Milestone Setting
+++ Resource Allocation
+ System Design
++ Architecture Design
+++ Technology Selection
+++ Interface Definition
++ Detailed Design
+++ Database Design
+++ Module Design
+ System Development
++ Frontend Development
+++ Page Implementation
+++ Component Development
++ Backend Development
+++ API Development
+++ Business Logic
+ Testing & Launch
++ Unit Testing
++ Integration Testing
++ Deployment
@endwbs

Mermaid 版

Mermaid’s WBS syntax uses - to denote levels, providing a clean tree structure:

wbs
  Project Planning
    - Requirements Analysis
      - User Interviews
      - Competitor Research
    - Project Planning
      - Milestone Setting
      - Resource Allocation
  System Design
    - Architecture Design
      - Technology Selection
      - Interface Definition
    - Detailed Design
      - Database Design
      - Module Design
  System Development
    - Frontend Development
      - Page Implementation
      - Component Development
    - Backend Development
      - API Development
      - Business Logic
  Testing & Launch
    - Unit Testing
    - Integration Testing
    - Deployment

对比 / Side-by-side

Feature	PlantUML	Mermaid
Diagram type	`wbs`	`wbs`
Level prefix	`+`	`-`
Node coloring	via `<<` stereotype	not supported
Auto-layout	yes	yes
Note annotations	via `note`	not supported

小结 / Wrap-up

PlantUML’s WBS suits scenarios needing fine-grained styling control, with support for colors, fonts, and stereotypes. Mermaid’s WBS wins on simplicity and readability when embedded in Markdown docs. Both let you quickly structure project tasks — pick based on your team’s toolchain.