Fishbone diagram

A visual root-cause analysis tool that shows a stated problem at the head and organizes possible causes along branching 'bones' by category, allowing the team to drill down into sub-causes; also known as a cause and effect diagram.

Key Points

  • Clarifies the relationship between an effect (problem) and potential causes grouped by category.
  • Built through facilitated brainstorming; teams ask "why" repeatedly to add deeper sub-causes.
  • Typical categories include Methods, People, Materials, Equipment/Technology, Environment, and Measurement (adapt as needed).
  • Supports problem exploration; findings should be validated with data before selecting corrective actions.

Example

During Control Quality on a software project, the team faces recurring login failures. The project manager leads a fishbone (cause and effect) session. Categories include People, Process, Tools, Environment, and Requirements. The team maps sub-causes such as ambiguous acceptance criteria, flaky test environment, missing input validation, and skipped peer reviews. These insights guide targeted experiments and fixes.

PMP Example Question

During a quality review, a project team wants to structure and brainstorm potential reasons for a persistent defect before running experiments. Which tool should the project manager use?

  1. Pareto chart
  2. Fishbone diagram (cause and effect diagram)
  3. Control chart
  4. Scatter diagram

Correct Answer: B — Fishbone diagram (cause and effect diagram)

Explanation: A fishbone diagram is used to brainstorm and organize possible causes of a problem by category before validating them with data.

How To Land the Job and Interview for Project Managers Course

Take the next big step in your project management career with HK School of Management. Whether you're breaking into the field or aiming for your dream job, this course gives you the tools to stand out, impress in interviews, and secure the role you deserve.

This isn’t just another job-hunting guide—it’s a tailored roadmap for project managers. You’ll craft winning resumes, tackle tough interview questions, and plan your first 90 days with confidence. Our hands-on approach includes real-world examples, AI-powered resume hacks, and interactive exercises to sharpen your skills.

You'll navigate the hiring process like a pro, with expert insights on personal branding, salary negotiation, and career growth strategies. Plus, downloadable templates and step-by-step guidance ensure you're always prepared.

Learn from seasoned professionals and join a community of ambitious project managers. Ready to land your ideal job and thrive in your career? Enroll now and take control of your future!



Launch your career!

HK School of Management delivers top-tier training in Project Management, Job Search Strategies, and Career Growth. For the price of a lunch, you’ll gain expert insights into landing your dream PM role, mastering interviews, and negotiating like a pro. With a 30-day money-back guarantee, there’s zero risk—just a clear path to success!

Learn More