5 Why analysis
Introduction
- The 5 Why analysis is a simple yet powerful problem-solving tool consisting of asking “Why?” as many times as is required to uncover the root causes of a problem. Each question digs deeper into the cause-and-effect relationship underlying a problem, ultimately revealing the real issues that needs to be addressed.
- The 5 Why analysis helps teams move beyond symptoms and immediate causes to tackle the true source of problems, leading to more effective solutions.
- It is widely used across industries for its straightforwardness and ability to encourage thorough analysis without requiring complex tools or extensive data.
Types of causes
Causes can be classified into the following types:
Direct cause
- The first cause that directly resulted in the problem.
- This is the answer to your first Why?” on your problem statement which you identified using the Fishbone diagram.
Contributing cause
- The cause(s) that contributed to a problem but, by itself, would not have caused the problem – the cause of the direct cause or another contributing cause.
- This is the answer to your further ”Why’s?”
Root cause
- The last cause and the fundamental reason for a problem, which if corrected, will prevent recurrence of the same problem.
- This is the answer to your last ”Why?”
Transitioning from Fishbone diagram
- Using the direct causes identified as probable causes in the Fishbone diagram as starting points for the 5 Whys analysis is a structured approach to delve deeper into each cause and understand its underlying causes. This transition facilitates a systematic exploration of root causes.
- It involves asking “why” repeatedly for each answer obtained, probing deeper with each question to identify contributing causes, until the root cause is identified.
Risk of subjectivity
The 5 Why Analysis is a simple yet powerful tool for root cause analysis, but it carries the risk of subjective bias influencing the outcome. This risk arises when the person or team conducting the analysis unconsciously or consciously steers the process toward a preconceived idea or outcome rather than following the facts. Here’s an expansion on how and why this happens, and its implications:
Confirmation bias
Confirmation bias occurs when someone selectively gathers or interprets information in a way that supports their pre-existing beliefs or conclusions. When performing the 5 Whys, the individual might unconsciously ask questions or interpret answers in a way that confirms what they already think the root cause is. This leads to overlooking other possible causes that might be more accurate.
Example: If someone believes that the issue is due to poor worker training, they might structure the Whys in a way that consistently points to human error, even if equipment failure is the real root cause.
Oversimplification
This is the tendency to accept the first plausible explanation without exploring other possibilities. The person conducting the 5 Whys might stop prematurely when they reach an answer that seems “good enough” or aligns with their assumptions. As a result, deeper or more complex root causes may not be uncovered, leading to incomplete or ineffective corrective actions.
Example: If the initial answer points to a superficial cause, such as “the machine was not calibrated,” the analysis may stop there, without digging into why it wasn’t calibrated (e.g., lack of a proper maintenance schedule).
Influence of Experience and Expertise:
The person’s background, expertise, or role may unconsciously influence the direction of the questioning. Someone with a background in a specific area (e.g., machinery maintenance, operations management) may focus more on causes related to their field of expertise and neglect causes outside of their domain. This leads to a skewed analysis that doesn’t fully account for all possible causes.
Example: A maintenance engineer might focus on equipment issues, while ignoring potential human factors, such as unclear operating procedures or lack of training.
Blame-Shifting or Organizational Politics:
Organizational dynamics, including power relations, accountability, and politics, can influence how root cause analysis is performed. There is a danger of the 5 Whys being used to protect certain individuals or teams from blame or accountability. In such cases, the analysis might be directed toward causes that are external or seen as “safe” rather than the true root cause.
Example: A manager may guide the analysis toward blaming external suppliers instead of acknowledging internal process failures or managerial oversights to avoid repercussions.
Lack of Objectivity:
Personal involvement in a problem can cloud judgment, leading to biased questioning and conclusions. If the person conducting the 5 Whys is too close to the problem, emotionally invested, or responsible for the process, they may unconsciously try to shape the outcome to minimize their own responsibility or that of their team. Objectivity can be compromised, leading to a less accurate root cause analysis.
Example: A supervisor responsible for a faulty process might unconsciously steer the analysis toward blaming external factors like materials or suppliers rather than examining the internal processes under their control.
Tunnel Vision:
This refers to focusing too narrowly on one potential cause and ignoring other possibilities. By getting “locked in” on one specific cause early in the analysis, the person performing the 5 Whys might fail to explore a broader range of potential contributing factors. This can lead to incomplete problem-solving.
Example: If the analysis starts with the assumption that the problem is caused by “poor communication,” all subsequent Whys might stay within the realm of communication issues, ignoring other technical, procedural, or environmental factors.
Mitigating the risk
To counteract these risks, several practices can be implemented:
- Involve a diverse team: Bringing in multiple perspectives helps reduce the risk of bias from any one individual and ensures that different potential causes are considered.
- Base each “Why?” on data and facts: Make sure that each question is answered using factual evidence rather than assumptions or opinions. This ensures the analysis remains grounded in reality.
- Challenge assumptions: Encourage participants to critically question each other’s answers and challenge assumptions that arise during the process.
- Document the analysis: Recording each step in the 5 Whys process makes it easier to review and verify the logical flow and ensures transparency in decision-making.
- Use supporting tools: Combine the 5 Whys with other analytical tools, such as Fishbone Diagrams or Pareto Analysis, to ensure that multiple causes are considered and prioritized based on evidence.
The 5 Why process
- When you do the 5 Why analysis, don’t simply ask “Why?”, but include the statement you are asking the “Why?” for.
- Here is an example: New 9.5l clear plastic storage box cracks on corners. Why does the 9.5l clear plastic storage box crack on corners? Answer: Weak points at the corner. Why are there weak points at the corners? Answer: Design does not adequately distribute stress. > Why does the design not adequately distribute stress? And so on…
- The reasons for including the statement are:
- Simply asking “Why?” may lead to vague or overly general answers because it lacks clear reference to the statement you are trying to address. Including the full statement ensures that the context of each “Why?” is retained. This keeps the analysis focused on the specific issue and reduces the chances of diverging.
- Simply asking “Why?” without context can lead to surface-level or overly simplistic responses, as the connection to the original statement might be lost. Using the full statement helps in systematically drilling down into the issue, ensuring that each layer of questioning builds on the previous one.
- Simply asking “Why?” risks producing answers that are not logically tied to the statement being analyzed. It can lead to assumptions or irrelevant answers. The full statement approach ensures that each answer directly addresses the specific statement and that the analysis progresses in a logical, step-by-step manner.
