How to Use Fishbone Diagram for Effective Problem-Solving

Using a fishbone diagram is an excellent way to simplify a complex problem. It encourages team collaboration, creativity, and communication and helps to identify cause and effect relationships.

Let’s explore the anatomy of the fishbone diagram that is crucial in various industries. Today we will see how this chart has evolved and help you with an easy-to-understand example. 

What is Fishbone Diagram?

The fishbone diagram helps visualise the causes of a problem to be organised into meaningful categories. The main purpose is to relate the causes to an effect. Resembling the skeleton of a fish, the head defines the problem or the effect. While the diagonal rib-like lines branch off the horizontal spine-like line to display the major and minor causes. 

This diagram is one of the 7 QC tools used across quality management areas, such as Six Sigma. This root-cause analysis visualisation tool is also popularly called the Ishikawa diagram. 
Also see histogram for further analysis together with the quality tools. 

There are various applications of it, beyond quality control in manufacturing.

Also, the fishbone diagram in project management has its use as an effective problem-solving technique in complex projects. Teams can transparently analyse the interdependent, contributing factors that lead to bottlenecks, or, to generate ideas through brainstorming. 

Other disciplines where the cause and effect diagram is of use include marketing, product development, customer service, and sales processes. 

Development of Fishbone Diagram

The fishbone diagram is usually credited to Dr Kaoru Ishikawa. He was also behind the concept of Quality Circle, roughly two decades later, where the use of the 7 QC tools, including this cause and effect diagram was prioritised. 

Dr Ishikawa also used the cause and effect concept together with W Edwards Deming and Joseph Juran. 

His main goal to use this cause-and-effect analysis was to identify the real causes of a problem rather than identifying symptoms. The reason being, the more one looks into symptoms, the further they move away from coming up with long-term solutions. Symptoms can be easily fixed, while identifying the root causes provides context, which helps in eliminating the issues once and for all.

Components of the Traditional Fishbone Diagram

It is important to note that the fishbone diagram was initially used in the field of manufacturing, where Dr Ishikawa described 5 M’s as the main causes for a production defect as an effect. 

Manpower (People): This category includes factors related to human resources, skills, knowledge, training, motivation, and the role of people in the process. It focuses on how individuals and teams contribute to the problem or its solution.

Methods: Here the sub-causes can include the processes, procedures, and workflows involved in the issue. This is to examine how the way tasks are performed might be influencing the problem.

Machines (Equipment): Machines refer to the tools, equipment, technology, and machinery used in the process. This category examines whether issues with the tools being used are contributing to the problem.

Materials: Materials include all the resources, substances, components, and inputs required for the process. This category explores whether the quality or availability of materials is affecting the outcome.

Measurement (Metrics): Measurement involves the data, metrics, and measurements used to assess the process or outcome. It considers whether the data being collected is accurate, relevant, and sufficient for making informed decisions.

Why Use the Fishbone Diagram?

From a high-level view, here are a few reasons to use a fishbone diagram.

1. Problem Analysis: Helps in identifying potential reasons for a problem.
2. Brainstorming Tool: Encourages team participation in problem-solving.
3. Visual Representation: Provides a structured visualization of potential causes.
4. Root Cause Analysis: Assists in determining the root cause of a problem.
5. Quality Control: Popularly used in Total Quality Management and Six Sigma processes.

How is the Fishbone Diagram Used across Different Industries

Sector	Problem	Potential Causes (examples)	How Fishbone Diagram Helps
Manufacturing	Defective Products	Machinery calibration, Operator error, Quality of material	Identifies areas of the production process that need improvement; promotes a systematic approach to troubleshooting and quality control.
Healthcare	Patient Wait Time	Staff shortage, Inefficient processes, Equipment downtime	Pinpoints bottlenecks in patient flow and areas where resources are lacking; can lead to improved patient experience.
Marketing	Declining Sales	Poor advertising, High pricing, Low product quality	Highlights areas in the marketing mix that might be weakening sales; offers a platform for brainstorming innovative strategies.
Software Development	Software Bugs	Inadequate testing, Code complexity, Lack of documentation	Provides a structure for development teams to analyze and reduce defects; encourages better software development practices.
Service Industry	Customer Complaints	Poor service training, Long wait times, Product issues	Uncovers gaps in service delivery; can lead to targeted training or process changes to improve customer satisfaction.
Education	Declining Student Performance	Curriculum difficulty, Teaching methods, Lack of resources	Offers educators a way to dissect the factors affecting student success; may result in curriculum or teaching adjustments.

How to Create a Fishbone Diagram

Find this step-by-step guide to creating a fishbone diagram. 

Define the Problem 

Clearly articulate the problem you’re addressing. This will serve as the central line and the head of the fishbone diagram.

Identify Main Categories 

Determine the main categories that could contribute to the problem. These are often the 5M’s: Manpower, Methods, Machines, Materials, and Measurement. Draw a horizontal line (the “spine”) and label each branch with the main categories.

Brainstorm Subcategories 

Under each main category, brainstorm potential subcategories or specific factors that might be causing the problem. These will be the diagonal lines branching off from the main categories.

You could even involve relevant team members or stakeholders in the brainstorming process. Different perspectives can lead to a more comprehensive analysis.

Along each subcategory line, brainstorm potential causes that fit within that category. Encourage open discussion and idea generation.

Once that is done, arrange the causes in a logical sequence, from broad causes closer to the main categories to more specific causes closer to the problem statement.

Analyse and Prioritise 

Review the diagram and analyse the potential causes. Identify which ones are most likely to be the root causes and prioritise them based on their impact.

Fishbone Diagram Example

Taking from the above 5M’s of the Fishbone diagram, let’s consider a scenario where the issue is Low Sales for a New Product Launch. 

Problem Statement: Low Sales for a New Product Launch.

Main Categories (5M’s)

Manpower (People)

• Inexperienced Sales Team
• Lack of Marketing Expertise
• Insufficient Training on New Product

Methods

• Ineffective Marketing Strategies
• Poor Market Research
• Limited Advertising Channels

Machines (Equipment)

• Outdated Point-of-Sale Systems
• Inadequate Online Shopping Platform with no CRM 

Materials

• Poor Packaging Design
• Low-Quality Product Materials

Measurement (Metrics)

• Inaccurate Sales Forecasting
• Lack of Key Performance Indicators (KPIs)

Sample Causes Under Subcategories

Inexperienced Sales Team (Manpower)

• Newly Hired Salespeople
• Lack of Product Knowledge Training

Lack of Marketing Expertise (Manpower)

• No Marketing Specialist on the Team
• Limited Understanding of Target Audience

Ineffective Marketing Strategies (Methods)

• Non-Engaging Social Media Campaigns
• Generic Marketing Messages

Poor Market Research (Methods)

• Inadequate Understanding of Customer Needs
• Limited Competitive Analysis

Outdated Point-of-Sale Systems (Machines)

• Slow and Unreliable Checkout Process
• Difficulty in Processing Transactions

Poor Packaging Design (Materials)

• Unattractive Packaging
• Inadequate Information on Packaging

Inaccurate Sales Forecasting (Measurement)

• Reliance on Assumptions Rather Than Data
• Limited Historical Sales Data for Similar Products

Analysis and Action Plan

Based on the fishbone analysis, the marketing team could implement the following actions:

• Provide thorough product knowledge training to the sales team.
• Hire a marketing specialist or work with external experts.
• Revise and tailor marketing strategies for better engagement.
• Conduct comprehensive market research to identify customer needs.
• Upgrade point-of-sale systems for smoother transactions.
• Redesign the product packaging to be more appealing.
• Invest in accurate sales forecasting tools and data analysis.
• Develop a detailed sales and marketing plan with specific KPIs.