In the maintenance world, addressing persistent issues can seem like detective work. You're presented with symptoms, but the underlying cause remains elusive; This is where the power of fishbone diagrams comes into play. Also known as Ishikawa or cause-and-effect diagrams, these tools provide a structured way to explore the root causes of problems. They are an invaluable asset when paired with the analytical capabilities of a Computerized Maintenance Management System (CMMS).
Table of Contents
A Fishbone Diagram, also known as an Ishikawa Diagram or a Cause and Effect Diagram, is a visual tool for problem-solving and brainstorming in quality management and continuous improvement processes. Its purpose is to identify, explore, and visually display the root causes of a specific problem or issue.
The name comes from the diagram's resemblance to a fish's skeleton, with the 'head' representing the problem and the 'bones' branching off the 'spine' representing possible causes. Each 'bone' can further branch out into sub-causes, allowing a detailed exploration of the issue. It was originally developed by Dr. Kaoru Ishikawa, a Japanese quality control expert, hence the alternate name, 'Ishikawa Diagram.' This tool helps teams to categorize, understand, and tackle the root causes of a problem instead of simply addressing its symptoms.
A fishbone diagram breaks down potential causes of a problem into categories, which are often referred to as the "6Ms" - Methods, Machines, Materials, Manpower, Measurement, and Mother Nature (Environment). The problem or effect is written at the 'head' of the fish, and the possible causes are charted along the 'bones,' giving a visual representation of potential root causes. This systematic approach makes identifying relationships between contributing factors easier, facilitating more targeted solutions.
Fishbone diagrams work by systematically sorting and relating the causes of a particular problem or effect. Here's a step-by-step process explaining how they work:
Define the Problem First, you identify the problem or issue that needs to be solved. This problem statement is placed at the "head" of the fishbone diagram.
Draw the Backbone. Draw a horizontal arrow pointing to the problem statement. This arrow, also known as the "backbone" or "spine," is the base for cause branches.
Identify Cause Categories. Identify the major categories of causes. In many cases, the 6Ms (Methods, Machines, Materials, Manpower, Measurement, and Mother Nature) are used, especially in manufacturing. Other industries may use different categories more suitable to their context.
Identify Causes For each category, and brainstorm potential causes related to that category. These are written on smaller "bones" that branch off the main category lines, or major "bones." If a cause is complex, it can be broken down further into sub-causes, forming additional branches.
Analyze and Review the diagram. Look for causes that appear repeatedly - they might be significant. This organized visualization helps teams collaboratively figure out the root causes and strategize the next steps for problem-solving.
By visually mapping out the potential causes of a problem, fishbone diagrams help teams uncover the root causes, fostering more effective problem-solving efforts.
Fishbone Diagrams and the 5 Whys are effective problem-solving tools, often used in quality control and process improvement. However, they approach the task of identifying the root cause of a problem in slightly different ways.
Fishbone Diagrams, as previously explained, are visual tools that allow teams to brainstorm and organize different categories of potential causes related to a problem. They help teams explore multiple root causes of an issue, and their format encourages comprehensive exploration and prioritization of different possible causes.
The 5 Whys, on the other hand, is a method that involves repeatedly asking the question "Why?" to peel away the layers of an issue until the root cause is revealed. The premise is that asking "why?" five times from the effect of the problem can lead to the root cause, though the number of "whys" can vary depending on the specific problem. The 5 Whys is a straightforward technique that helps pinpoint a single root cause quickly but can oversimplify complex problems with multiple causes.
Fishbone diagrams are excellent for team brainstorming sessions and complex problems where there may be multiple root causes. They allow for visual organization and categorization of potential causes, fostering collective understanding and solution generation.
The 5 Whys method is a faster, simpler technique, best suited for straightforward problems or quickly getting to the heart of a problem. However, it may not fully address problems with multiple root causes or interconnected issues.
In practice, these two methods can be used together. The 5 Whys can be used within each branch of a Fishbone Diagram to dig deeper into each potential cause, thereby combining the comprehensiveness of Fishbone Diagrams with the root cause focus of the 5 Whys.
Creating an Ishikawa (Fishbone) Diagram involves systematic brainstorming and organization of potential causes of a problem. Here is a step-by-step guide on how to create one:
Define the Problem At the right side of a large blank space (whiteboard, large paper, digital drawing board), write down the problem you want to explore and draw a box around it. Draw a horizontal arrow leading to this box; this forms the "spine" or "backbone" of the fish.
Identify Major Cause Categories. Determine the major categories of causes that contribute to the problem. The common ones are often known as the 6 M's - Machines, Methods, Materials, Manpower (People), Measurements, and Mother Nature (Environment). Draw lines off the "spine" for each category and label them. The lines should angle out and away, giving it the shape of a fishbone.
Brainstorm Potential Causes. For each major cause category, consider all possible contributing factors. Draw these as smaller lines branching off the major cause lines.
Analyze Analyze the diagram. Are there common themes or cause categories that stand out? This will provide insights into the areas to focus on for improvement.
Plan Next Steps. Decide on the next actions to solve the problem based on your analysis. Who will do what, and by when? A follow-up session to review progress can also be helpful.
It's important to remember that creating an Ishikawa Diagram is typically a team effort. Multiple perspectives will offer a more comprehensive exploration of the problem's root causes.
Also, while the Fishbone Diagram helps you identify potential causes, it doesn't help you identify the exact root cause(s). You will need to investigate the identified potential causes further to determine their relevance and impact. Tools like the 5 Whys, Pareto Analysis, or Failure Mode and Effects Analysis (FMEA) can assist with this next step.
With CMMS software's data management and reporting capabilities, the fishbone diagram becomes a dynamic tool for problem-solving. The software can capture data relevant to each category, and as you dig deeper into the data, it helps illuminate potential root causes hidden within your maintenance operations.
Preventive maintenance lies at the heart of efficient operation management. Fishbone diagrams can be used to examine recurring equipment failures or inefficiencies and consequently improve preventive maintenance schedules. For instance, if 'Machines' repeatedly surface as a cause category for certain issues, it may be time to evaluate and improve preventive maintenance routines for those assets.
When problems persist despite your best efforts, a root cause analysis (RCA) can help resolve the issue. RCA is a methodical approach to problem-solving, and fishbone diagrams provide a framework to identify, explore, and display potential root causes. Using a fishbone diagram alongside your CMMS software lets you draw on historical data to inform your analysis, ultimately leading to more effective problem resolution.
In essence, when used in conjunction with CMMS Software, fishbone diagrams can transform how you approach maintenance problems. They help turn data into actionable insights, improving preventive and predictive maintenance strategies and fostering a proactive maintenance culture. By employing these diagrams, you'll be better equipped to eliminate those pesky maintenance issues.
When the fishbone diagram's power of structured problem-solving meets CMMS software's robust data management capabilities, you're well on your way to a streamlined, efficient maintenance operation.
