Applying the 5 Whys in Cybersecurity Audits

The 5 Whys methodology, when applied with care, can significantly enhance internal audits and compliance efforts in cybersecurity. It aligns perfectly with the continuous improvement ethos of standards like ISO and NIST – turning every audit finding or incident into a chance to strengthen the system. With digging down to root causes your organization can avoid superficial fixes and instead implement changes that are more effective and permanent​.

In this Article

What is the 5 Whys Methodology?

The 5 Whys technique is a simple but powerful method for root cause analysis. It was originally developed in the 1930s by Sakichi Toyoda (founder of Toyota) as part of the Toyota Production System. The method involves repeatedly asking the question “Why?” – typically five times – to drill down from an observed problem to its underlying cause.

With successively questioning why a problem exists, practitioners trace a direct chain of cause-and-effect until the fundamental root cause is identified.

The number five is a rule of thumb – in practice it may take fewer or more “why” iterations depending on the complexity of the issue. The key principle is to look beyond immediate symptoms and avoid assumptions, so that the analysis uncovers the process or system failure at the heart of the problem.

Developed as a problem-solving tool in manufacturing, 5 Whys has since been widely adopted in various domains such as lean management and Six Sigma​. It is valued for its simplicity and effectiveness: it requires no statistical tools, only critical thinking and inquisitiveness.

The technique encourages teams to focus on processes rather than individuals when analyzing issues, fostering a blameless, fact-driven approach to improvement​. With continually asking “why” in a disciplined way, organizations can uncover hidden weaknesses and address them to prevent the problem from recurring.

The 5 Whys is about peeling away layers of causes – much like a detective interrogating a problem – until the true root cause is revealed​. This methodology sets the stage for lasting solutions, as fixing root causes (rather than patching symptoms) ensures that issues are truly resolved.

Application in Cybersecurity Audits

In the context of cybersecurity frameworks and compliance (e.g. ISO/IEC 27001:2022, ISO 42001 for AI, NIST CSF, SOC 2, etc.), the 5 Whys technique can greatly enhance internal audits and corrective action processes.

These frameworks mandate regular internal audits or assessments to verify that security controls and processes are in place and effective. When an audit uncovers a non-conformity or security incident, merely fixing the immediate problem is not enough – the underlying cause must be understood and addressed to prevent recurrence.

ISO 27001’s management system model (Plan-Do-Check-Act) explicitly requires organizations to take corrective actions for identified issues, and performing a root cause analysis is strongly advised so that fixes “get to the bottom of why or how it happened”​. A simple tool like 5 Whys is recommended to ensure that any corrective action truly eliminates the root cause of the non-conformity​.

If you don’t identify the underlying why, “whatever fix you implement will not be fully effective”​. This philosophy holds true across cybersecurity standards: effective risk management depends on learning from incidents and audit findings by identifying their causes.

Using 5 Whys in an internal audit

Using 5 Whys in an internal audit means that when an issue is found – whether it’s a failed control, a policy gap, or a security breach – the audit team or relevant stakeholders ask “why” iteratively to diagnose the failure.

The 5 Whys approach can be applied to a broad range of scenarios, from procedural non-compliances to technical security incidents.

Often, what initially appears to be the cause (e.g. “user clicked a phishing email”) is only a symptom of deeper organizational issues (e.g. “lack of security awareness training” or “no process to cover training when staff are absent”).

With digging into multiple “whys,” auditors can uncover non-technical factors that contributed to the lapse – such as inadequate governance, missing processes, or oversight failures​. This aligns with guidance from NIST, which defines root cause analysis as

“a principle-based, systems approach for identifying underlying causes associated with a particular set of risks”.

The goal is to find the systemic reason the issue occurred, not just the immediate trigger.

Example: Consider an internal audit finding that the organization was infected by the WannaCry ransomware. A 5 Whys analysis might proceed as follows:

The immediate problem is “system infected by WannaCry.”

  • Why did this happen? – Because an employee clicked on a malicious email link, which downloaded the malware​.
  • Why did they click the link? – Because they had not received proper phishing awareness training​.
  • Why was there no training? – The training manager was on extended leave and no one was assigned to cover that responsibility​.
  • Why was there no backfill for that role? – Because the staff leave process was not addressed in the security training program or risk assessments, so the gap went unnoticed​.

In this analysis, by the fourth “why” the audit team discovers a root cause: a process gap in managing personnel changes (the security training halted when the manager went on leave).

This insight goes far deeper than the initial observation of user error. The organization can now take corrective action at the process level – for instance, updating the change management or HR procedures to ensure critical security roles are covered during absences – thereby preventing similar incidents in the future.

This illustrates how 5 Whys during a cybersecurity audit can reveal underlying control weaknesses that might otherwise be overlooked.

ISO/IEC 42001:2023 (AI Management System) requires that information security incidents and audit findings be reviewed and that corrective actions address the root causes of non-conformities. An organization governing AI could use 5 Whys to investigate, say, a failure in an AI model’s outcome or an AI ethics compliance issue – the technique would uncover if the cause was insufficient training data, lack of bias testing, poor oversight, etc., guiding compliance improvements.

ISO/IEC 27001:2022, likewise, follows a similar improvement cycle: it mandates internal audits (clause 9.2) and corrective actions to avoid nonconformity (clause 10.2)​. requires that information security incidents and audit findings be reviewed and that corrective actions address the root causes of non-conformities. Implementing 5 Whys helps satisfy this by providing a structured way to document why a control failed and how to fix the originating issue.

NIST Cybersecurity Framework (CSF) emphasizes learning from incidents in its “Respond” and “Recover” functions; performing a root cause analysis (using 5 Whys or similar) after a security event aligns with NIST’s guidance to understand not just what happened but why. This turns reactive incident response into proactive risk management​.

SOC 2 (Service Organization Controls) audits, while external, often lead organizations to conduct internal remediation of control deficiencies – here too, asking “why did this control fail?” multiple times can distinguish between a one-off lapse and a deeper process issue that could impact trust services criteria. With using 5 Whys, a company preparing for a SOC 2 audit might discover, for example, that an access review wasn’t done not simply because an employee forgot, but because roles and responsibilities for that control were unclear – a root cause that can be fixed by clarifying procedures.

Integrating the 5 Whys into cybersecurity audit activities helps organizations move from a check-the-box mentality to one of continuous improvement. Rather than just remediating surface-level findings, they delve into causes like policy gaps, training issues, resource constraints, or cultural problems and address those.

Research on breaches shows that few incidents are caused by a single isolated failure – more often there is a chain of contributing factors​. 5 Whys enables an organization to map out that chain and tackle each weak link. 

Other Root Cause Analysis Techniques

The 5 Whys is one of several tools available for root cause analysis (RCA). In cybersecurity audits and risk management, other common techniques include the Fishbone Diagram (Ishikawa Cause-and-Effect), Fault Tree Analysis (FTA), Failure Mode and Effects Analysis (FMEA), and Pareto Analysis.

Each of these methods has distinct strengths and is suited for different scenarios​. We briefly explain these techniques and then compare them to the 5 Whys methodology.

Fishbone Diagram (Ishikawa Cause-and-Effect)

This is a visual brainstorming tool that resembles a fish’s skeleton. The “head” of the fish represents the problem (effect), and the “bones” branching off represent categories of potential causes (for example, common categories in manufacturing are Man, Machine, Method, Materials, etc.; in cybersecurity, categories might be People, Process, Technology, Environment, etc.).

Teams identify and list possible causes under each category branch, continually asking why those causes occur, until underlying root causes are identified at the ends of the branches​. The fishbone diagram allows exploration of multiple causes simultaneously, providing a holistic view of factors that lead to an incident or non-conformance. It is especially useful when a problem is complex and multifaceted – the visual layout helps organize causes and sub-causes and show relationships.

The 5 Whys technique is often used in conjunction with fishbone diagrams: for example, the team may populate the diagram by digging into each category with “why” questions​. The fishbone does not limit the inquiry to one linear path of questioning, so it’s good for ensuring no major cause category is overlooked. However, it requires group brainstorming and can become elaborate if many potential causes are considered.

Fault Tree Analysis (FTA)

FTA is a deductive, systematic technique that uses boolean logic to determine the combinations of failures that could lead to a particular undesired event (the “top event”). It works by starting with the incident or problem and mapping out, in a tree diagram, all the possible immediate causes.

Each of those causes is then broken down into their causes, and so on, using logical gates (AND/OR) to model how they combine to produce the higher-level event​. The result is a tree where the root nodes are basic causes and the branches show the pathways of failure.

FTA is commonly used in safety engineering and reliability engineering (e.g. aerospace, nuclear, aviation) because it handles complex interdependencies and can incorporate probability of each cause to quantify risk​. In cybersecurity, one might use FTA to analyze something like a system outage or security failure, mapping hardware faults, software bugs, human errors, and environmental factors that together could lead to the incident.

The strength of FTA is its rigor and detail – it forces a thorough examination of how multiple factors interact. The downside is that it requires significant expertise and data; it assumes causes are either present or not (a binary approach), which can make it too rigid for nuanced issues or partial failures​. FTA diagrams can also become very complex for large systems.

FTA is typically best suited for critical systems or high-impact failures where a deep dive is needed and quantifying risk is valuable.

Failure Mode and Effects Analysis (FMEA)

FMEA is a proactive, systematic method originally developed for reliability in engineering. Instead of analyzing one event backward, FMEA goes component by component (or process step by step) to identify all the ways each part could fail (failure modes), and what the effects of those failures would be on the larger system.

For each failure mode, FMEA typically evaluates its severity, frequency (occurrence likelihood), and detectability, often scoring these to compute a Risk Priority Number (RPN)​. This helps prioritize which failure modes pose the highest risk so that preventive actions can be taken.

FMEA is very thorough – it essentially anticipates problems before they happen – and is widely used in industries like automotive, aerospace and healthcare for quality and safety improvement (in fact, it’s been used by the U.S. Army and NASA since the 1950s)​.

In the context of cybersecurity or IT, one could use FMEA for processes like data backup, change management, or product development: e.g., identify potential failure modes (backup fails due to X, Y, Z reasons) and plan controls for each.

The benefit of FMEA is that it can drive continuous improvement and resilient design by addressing issues upfront. Its weakness is that it’s labor-intensive and requires cross-functional expertise to brainstorm all possible failure modes and keep the analysis updated​.

It also typically addresses one failure mode at a time in isolation (not great at scenarios where multiple things fail together)​. FMEA is most valuable for complex processes or systems where preventing problems is critical – it’s less commonly used for quick incident post-mortem analysis, but more for designing robust systems and processes.

Pareto Analysis

Pareto analysis is a more statistical/tool-based technique rather than a qualitative diagram. It’s based on the Pareto principle (80/20 rule), which in problem-solving often means that a majority of problems are caused by a few key causes.

In practice, Pareto analysis involves collecting data on the frequency or impact of problems and then charting them in a Pareto chart – a bar graph that ranks causes or issue categories from most frequent to least, usually combined with a line showing cumulative percentage. This helps identify the “vital few” causes that account for most of the impact. In a cybersecurity context, for example, an organization might log all security incidents over a year and find that, say, 80% of incidents come from 20% of root cause types (perhaps misconfigurations or unpatched software are the top contributors).

With focusing on those top issues, one can get the biggest risk reduction. The strength of Pareto analysis is prioritization – it uses real data to focus attention on the most significant factors​. It’s very useful in audit and compliance programs to decide where to allocate resources (e.g. which control failures happen most often). It can also show cumulative impact over time and improvements if the Pareto chart is generated periodically​.

Pareto analysis by itself doesn’t tell you why those top causes are happening; it just highlights what they are. Its limitations include relying on historical data (which may not predict new types of issues)​and the fact that it addresses “what” to tackle, not “how”. It also may not be meaningful if data is scarce or if issues are all unique.

Pareto is best for situations where you have multiple instances of incidents or non-conformities that can be categorized – it shines in identifying repetitive problems that contribute the most to risk, so you can then use a root cause tool (like 5 Whys or fishbone) on those specific issues.

Each of these techniques can complement one another. In practice, organizations might use 5 Whys for a quick analysis of a single incident, fishbone diagrams for brainstorming all possible causes of a complex problem, FTA for highly critical failures that require detailed modeling, FMEA to anticipate and prevent problems in a process design, and Pareto to identify trends in incident data.

Here we summarize the key strengths, weaknesses, and best-use scenarios of 5 Whys versus these other root cause analysis methods:

STRENGTHSWEAKNESSESBEST USE CASES
Simple and fast to apply – requires no special training or complex tools​. Uncovers underlying issues rather than superficial symptoms by prompting deeper inquiry​. Encourages a focus on processes instead of blame, especially when done in a team setting​.May be too basic for complex problems – limited depth if issues are multi-layered​. Results can be subjective and not repeatable – heavily dependent on the investigator’s knowledge and perspective. Tends to isolate a single root cause, potentially overlooking multiple contributing factors.Straightforward problems or singular incidents where a quick diagnosis is needed​. Situations involving human error or process failures (common in security lapses)​. Often used as a first step or in conjunction with other methods for more complex issues​.
STRENGTHSWEAKNESSESBEST USE CASES
Visual and comprehensive – maps out cause-and-effect across multiple categories, helping teams see relationships between different factors​. Fosters collaboration and brainstorming, often generating innovative insights into problems​. Good for exposing multiple potential root causes in complex scenarios (doesn’t limit analysis to one path).Can become complicated – handling many potential causes can make the diagram large and hard to interpret​. Risk of digression – brainstorming may produce irrelevant ideas, and categorization can add complexity that “makes the problem larger” than it is​. Does not by itself identify the root cause – it organizes hypotheses that still need verification.Complex or multifactor problems where causes may span various domains (technology, process, people, etc.) and a holistic view is needed​. Useful in team settings to pool knowledge on why an incident occurred. Often used in quality improvement and incident post-mortems to ensure no branch of cause is overlooked.
STRENGTHSWEAKNESSESBEST USE CASES
Structured and rigorous – provides a systematic, logical breakdown of causes using AND/OR logic, which is very effective for complex systems failures​. Can analyze multiple causes and their interactions simultaneously, and even support quantitative risk analysis (probabilities) for each branch​. Particularly strong for ensuring safety and reliability compliance by identifying points of failure in design​.Rigid and time-consuming – uses binary logic (cause present or not), which fails to handle partial or conditional contributions well​. Requires detailed knowledge and data; not easily done without expertise or software support. Not ideal for quick analysis, and the diagrams can be complex to build. Also, by itself FTA doesn’t easily show the probability of the top event without additional data analysis​.High-criticality incidents or system failures where thorough analysis is needed (e.g. a major security system outage, critical infrastructure breach). Common in safety-critical industries (aerospace, healthcare, nuclear) for analyzing hazards​. Also used in software/security engineering to debug complex issues by systematically ruling out causes​. Best when you can clearly define a top event and need to know all the combinations of faults that could lead to it.
STRENGTHSWEAKNESSESBEST USE CASES
Comprehensive and preventive – examines all possible failure modes in a process or system and evaluates their effects, which helps in prioritizing risks and addressing them before incidents occur​. Improves understanding of the system: leads to better work methods, maintenance plans, and even design changes to eliminate potential failures​. Especially useful for enhancing reliability, safety, and security in design and operations by systematic risk mitigation.Resource-intensive – conducting an FMEA is time-consuming and demands detailed knowledge of the system; it may require a team of experts and frequent updates as the system or environment changes​. Not suited for multiple simultaneous failures – tends to look at one failure mode at a time, so interactions between different failures can be missed​. If not exhaustive, can give false sense of security (a missed failure mode means an unrecognized risk)​.Design and process improvement stages – ideal when developing or updating systems/processes (e.g. rolling out a new security system or procedure) to identify and mitigate potential points of failure​. Used in high-risk industries and critical infrastructure (aerospace, automotive, AI systems) where proactive risk analysis is necessary. Not typically used after a single incident, but rather to prevent failures or in response to recurring problems by redesigning the process.
STRENGTHSWEAKNESSESBEST USE CASES
Data-driven focus – identifies the most significant causes by ranking issues in order of impact or frequency​. Helps in prioritizing efforts: by showing which few causes are responsible for the majority of problems, it guides where to apply resources for maximum improvement​. Easy to communicate via Pareto charts; gives a clear quantitative basis for decision-making and continuous improvement tracking.Limited insight – reveals “what is biggest” but not “why” the problems occur. Relies on historical data; if data quality is poor or circumstances change, results may mislead​. Not applicable if incidents are rare or unique (you need multiple data points for a Pareto pattern to emerge). Also, focusing only on frequency might overlook high-severity rare issues (which might be critical despite not being frequent).Recurring issues analysis – great for analyzing incident logs, audit findings, or helpdesk tickets to find which problems happen most often or cost the most, so you can target those for root cause elimination. Often used in continuous improvement programs to track and reduce the most common types of non-compliance or incidents. Best when you have quantifiable data on incidents (e.g., number of occurrences, financial impact) and want to apply the 80/20 rule to prioritize corrective action.

Implementation Strategies for Integrating 5 Whys in Cybersecurity Audits

Adopting the 5 Whys methodology in an organization’s internal audit and compliance process requires some planning and practice. We’ve outlined practical steps and strategies to integrate 5 Whys into cybersecurity audits and compliance reviews:

First, update your internal audit policies and procedures to explicitly include root cause analysis as part of the corrective action process. For every audit finding or security incident, there should be a step to determine why it occurred. For example, ISO 27001 requires that for each nonconformity, the organization determines the causes and evaluates if similar issues exist elsewhere before deciding on corrective actions​​. Define a standard approach – such as using the 5 Whys – for consistency. This can be documented in your audit report template: after noting the finding, have a section for “Root Cause (5 Whys Analysis)” where the auditor or responsible manager will document the chain of “why” questions leading to the root cause. By institutionalizing this, you ensure that everyone treats root cause identification as a necessary step, not an optional task.

Provide training to your internal auditors, risk management team, and control owners on how to perform a 5 Whys analysis effectively. Emphasize the mindset of digging deeper and relying on evidence for each answer. It’s important that those conducting the analysis understand to base each “why” on verifiable facts, not guesses​. Perhaps run a workshop with real or simulated examples (like analyzing a past incident) to practice the technique. Also, encourage a blame-free culture during these analyses – the goal is to fix processes, not assign personal blame. Team members should feel comfortable honestly probing issues (remember, even Toyota noted that asking “why” repeatedly is something even a child can do; it should be encouraged, not stifled​ en.wikipedia.org). If possible, include training on complementary tools like fishbone diagrams, so staff know how to expand the analysis if one line of questioning is not sufficient.

When an audit finding arises or an incident occurs, start by clearly defining the problem before asking “why.” Frame the problem statement in specific terms – e.g. “Database backup failed on 5/10,” or “User data was found unencrypted in cloud storage,” rather than a vague description. Agree on the scope of the problem being analyzed (what system or process it involves, time frame, etc.)​. This is crucial because asking “why” to a poorly defined problem can lead down unproductive paths or confusion. The audit team or incident response team should gather initial evidence (logs, reports, interviews) to fully understand what happened. For example, if a control failed, know in what way and when it failed. This ensures everyone is on the same page about the starting point for the 5 Whys analysis. As guidance, write the problem at the top of a 5 Whys worksheet or on a whiteboard as the starting point.

Whenever feasible, perform the 5 Whys analysis with a small team rather than a single auditor working in isolation. Involving multiple stakeholders (such as the control owner, an IT/security SME, maybe a process owner or manager) brings diverse perspectives that can enrich the analysis​. One person should act as the facilitator (often the auditor or risk manager) to pose the “why” questions, but the group can discuss and agree on answers. Each team member may think of different causes or have insights into different aspects of the problem. This reduces the chance of bias or of stopping at an answer that “sounds good” but isn’t the true root cause. It also ensures organizational buy-in – when people participate in finding the cause, they are more likely to support the corrective actions that follow. Make sure the discussion remains focused on the process or system factors, not on blaming any individual​. If sensitive issues come up (e.g. a management failure), keep the discussion respectful and oriented toward solving the problem.

Begin the analysis by asking the first “Why did this happen?” for the defined problem. Document the answer. Then treat that answer as the new problem and ask “why” again, and so on. It’s important to record each question and answer pair, either in a simple table form or narrative form, to create a trail of reasoning. This documentation will be useful for audit records and for reviewing the logic later. Ensure that for each “why,” the answer is rooted in evidence or observation (“We have evidence that X occurred because Y”). If an answer seems to introduce a conjecture, flag it for verification. A good practice is after each answer, ask the team “If we fix this, will the problem be prevented?”​. If the answer is “not sure” or “no, there could still be other factors,” then continue to the next “why.” Continue this iterative questioning until the team reaches a point where they collectively agree that the root cause has been identified – often this is a fundamental process gap or failure. It’s often observed that by the 3rd, 4th or 5th why, you uncover a systemic issue such as a policy not existing or a procedure not being followed​. There is no strict requirement to stop at exactly five questions; the rule is to go as deep as needed. Sometimes you might get there in three “whys,” other times you might need seven or more – use judgment and stop when fixing that cause would definitively prevent recurrence of the issue​.

The last answer in the 5 Whys chain should be tested for being a true root cause. A root cause in audits is typically a basic underlying issue that is within the organization’s control to fix and that addresses the overall problem, not just a one-time occurrence​. Verify that it is not a symptom of an even deeper issue. One way to confirm is to imagine if this cause were removed or corrected earlier, would the incident have been avoided? If yes, you’ve likely found the root cause. If the cause statement is still essentially describing a failure that could itself be caused by something else, you might need to dig further. For example, an answer like “Employee did not follow procedure” might hint that the root cause is human error – but ask why the employee didn’t follow procedure (Were they untrained? Was the procedure impractical? etc.) to get to a more actionable root cause such as “Training for that procedure was insufficient” or “Procedure is too complex and not user-friendly.” The final root cause statement should be specific and address a systemic issue (e.g. “No process to ensure security training during staff absences,” or “Legacy encryption tool not included in patch management program”)​. It should not contain blame or broad generalizations, and ideally it shouldn’t still have an implicit “why” in it (meaning it is self-contained and factual)​.

Once the root cause is identified, the next step is to determine how to fix it and prevent the problem from recurring. Some organizations use a “5 Hows” technique as a complement to 5 Whys – essentially asking “How can we address this cause?” repeatedly to brainstorm a robust solution​. Whether or not you formalize that, the team should come up with one or more corrective actions targeting the root cause. These actions should be specific, measurable, and assigned to an owner with a target date. For example, if the root cause was “lack of a process for X,” the corrective action might be “Develop and implement a standard operating procedure for X by [date], and train relevant staff.” If the root cause was a missing control, the action could be “Implement [control] and integrate it into the monitoring program.” In our WannaCry example, a corrective action was to update the change management procedure to require a risk assessment and coverage plan when key staff go on leave​. It’s also wise to identify any secondary causes uncovered during the 5 Whys (issues that came up along the way) and ensure they are addressed if needed. Document the action plan clearly linking it to the root cause. This could be in an audit CAPA (Corrective and Preventive Action) form or tracking system.

Execution is crucial – ensure the corrective actions are implemented by the responsible persons. Leadership should support providing resources or policy changes needed. Once actions are in place, monitor their effectiveness. For instance, if the action was new training or process, the next internal audit or a special review should check whether that has resolved the issue. It can be helpful to define a measure of success for the corrective action (e.g., “no repeat of incident X in the next year” or “audit in six months shows compliance with new process”). If the issue was severe, consider doing a lessons learned report or meeting to share the results of the 5 Whys analysis and the fixes with a broader team, reinforcing a culture of learning. Over time, organizations can even build a knowledge base of root causes and fixes from past audits and incidents, which can speed up analysis of future issues.

In practice, not every minor finding will need a full 5 Whys treatment – organizations should prioritize. As a strategy, use a risk-based approach: focus root cause analysis on high-risk or recurring issues first. If resources are limited, a quick risk assessment can determine which findings warrant deep analysis​. For example, a trivial one-off paperwork error might just be corrected without a multi-why analysis, whereas a security incident or a major compliance gap should absolutely get a thorough 5 Whys investigation. Many companies formalize this by requiring RCA for any incident above a certain severity or any audit finding rated medium or high risk. This ensures effort is spent where it truly adds value. That said, even “small” problems can reveal important process improvements, so encourage staff to use the 5 Whys informally as a problem-solving mindset whenever something goes wrong.

To illustrate, consider a case study of implementing 5 Whys in practice (beyond the WannaCry scenario).

A financial services company noticed during an internal audit that several privileged user accounts had not had their access rights reviewed in over a year, violating the company’s access control policy.

They applied a 5 Whys analysis:

  • Why? – Because the quarterly access review process was not followed for those accounts.
  • Why was it not followed? – The responsible manager was unaware those accounts existed on a legacy system.
  • Why? – Because the inventory of privileged accounts was incomplete (the legacy system wasn’t included in the review scope).
  • Why was it incomplete? – There was no centralized tracking for legacy system accounts and no clear ownership defined for them.
  • Why? – The deprovisioning process for that old system was never integrated into the standard IAM procedures.

Here, the root cause turned out to be an integration gap in identity management procedures for legacy systems.

As a corrective action, the company updated its IAM policy to include all systems (old and new) in access reviews, implemented a reconciliation script to catch any accounts outside the centralized IAM tool, and assigned an owner for the legacy system’s accounts. In the next audit, all accounts were being reviewed as required.

This example shows how 5 Whys can lead to very targeted fixes (in this case, policy and process changes in the IAM domain) that strengthen compliance with frameworks like ISO 27001 or SOC 2. Over time, these small improvements accumulate into a much more robust security management system.

To integrate 5 Whys into your cybersecurity audit program: make it a standard practice, equip your people to do it well, use it on the problems that matter most, and follow through with strong corrective actions.

Challenges and Limitations of Using “5 Whys” in Security Audits

While the 5 Whys methodology is a useful tool, it is not without challenges – especially in the complex domain of cybersecurity. Being aware of these limitations allows an organization to mitigate them and use 5 Whys more effectively:

A common pitfall is that investigators might stop asking “why” too soon and end up addressing a symptom rather than the true root cause. In fast-paced environments, there can be a tendency to reach a quick conclusion and fix the first apparent cause.

An analysis might stop at “the firewall rule was misconfigured by mistake” and conclude the solution is “retrain the admin”, without digging into why the mistake happened (perhaps workload issues or change process problems). To avoid this, teams must be disciplined to push past superficial answers. A useful check is to see if the “cause” identified is something that could itself have an underlying cause. If yes, ask “why” again. Management should encourage a thorough analysis rather than a fast one.

The quality of a 5 Whys analysis is heavily dependent on the knowledge and perspective of the people involved. The method provides no built-in mechanism to discover causes outside the investigators’ experience.

This means if the team isn’t aware of a particular technical issue or an organizational factor, that cause might never surface in the analysis. Different people might even find different “root causes” for the same problem​, indicating a degree of subjectivity. In cybersecurity, where problems can span multiple domains (IT infrastructure, human behavior, third-party components, etc.), a single person might not have the full picture. This is why involving a cross-functional team and, when needed, subject matter experts is important – it broadens the knowledge pool so that less obvious causes are considered.

Additionally, the team can do some research or data gathering between “why” iterations if they hit an area of uncertainty (for instance, if a potential cause is “software bug,” they might pull in a developer to confirm whether a bug existed or not).

Another challenge is finding the right balance in analysis. On one hand, there is a risk of oversimplifying complex issues by following just one line of inquiry.

Cybersecurity incidents often have multiple contributing factors (e.g., a breach might occur due to a combination of a phishing email and a missing patch and a slow incident response). A single chain of “why” may not capture this multifaceted reality. If the 5 Whys is applied naively, one might erroneously isolate a single root cause (“it was all because of that missing patch”) while ignoring other causes​. On the other hand, trying to incorporate multiple branches into a linear 5 Whys can lead to analysis paralysis or confusion. The technique isn’t naturally suited to branching causes.

Mitigation: if an issue clearly has distinct cause streams, it might be worth performing separate 5 Whys analyses on each symptom or using a fishbone diagram to map multiple causes, then doing 5 Whys on each branch. In practice, combining 5 Whys with a broader cause brainstorming ensures you’re not missing anything​. After using 5 Whys to drill down one path, you can always go back to a top-level view and ask “Are there other reasons this happened?” to catch additional factors.

Sometimes the 5 Whys turns into speculation if not kept in check by evidence.

Especially in audits, one must ensure that each answer is backed by facts (audit evidence, logs, witness interviews, etc.)​. If not, the analysis can go astray into hypothetical territory (“Maybe it was because of X…”). This not only wastes time but can produce a root cause that is incorrect. To mitigate this, it’s good practice to verify assumptions at each step.

If one answer is “admin didn’t follow procedure due to workload”, verify if there were indeed workload issues (e.g. multiple projects assigned to that admin). If such verification is not possible, note that as a gap and consider addressing it (maybe the root cause is actually that the organization isn’t monitoring workload – which is a different insight). Essentially, keep the analysis factual: as one guide cautions, do not let 5 Whys devolve into a deductive guessing game – it should be grounded in what actually happened​.

Because 5 Whys can yield different results depending on who performs it and how the questions are framed, there is a challenge in consistency.

Two audit teams analyzing similar incidents might report different root causes, which can be problematic for an organization trying to spot trends or ensure consistent controls. One mitigation is to standardize the approach (through training, templates, and perhaps oversight).

Having a second pair of eyes review the 5 Whys analysis (such as a quality manager or a peer auditor) can provide a sanity check. Also, if the same issue occurs again, reviewing the previous root cause analysis can help determine if the cause was correctly identified or if something was missed, thereby improving consistency over time.

Relatedly, 5 Whys by design tends to identify one primary root cause for each problem.

In reality, complex problems can have multiple root causes or contributing causes. Focusing on just one might mean missing additional corrective actions. For example, a security breach might have succeeded both because of a firewall misconfiguration and because an intrusion alert was ignored. If you only chase the firewall misconfiguration “why,” you might miss the alerting process issue.

To counter this, it’s important after finishing a 5 Whys chain to ask, “Is there anything else that allowed this problem to occur?” If yes, you might need to do another 5 Whys on that aspect. Also, using tools like Ishikawa diagrams as a preliminary step can surface multiple cause streams to investigate​.

Another trick: have the team identify at the start all possible causes (brainstorm), then use 5 Whys on the most likely ones. This ensures the final result isn’t just an artifact of initial tunnel vision.

How the “why” is asked can influence the answers. If questions are leading or too narrow, they may bias the outcome.

For example, asking “Why did the employee click the phishing email?” might lead to blame the employee’s action, whereas asking “Why was the phishing email successful?” opens the door to process issues (training, email filters, etc.). Auditors should be trained to phrase “why” in an open-ended way and possibly vary the wording (“What caused…?”, “How come…?”) to get different angles.

If the conversation gets stuck, rephrasing the why or stepping back a level can help.

In some cases, the true root cause may be uncomfortable – such as “tone at the top” issues (e.g., lack of management support for security) or an individual’s performance.

In the ISACA Journal example, one root cause for a persistently messy network closet was that an employee felt untouchable due to a guaranteed job contract, and simply refused to comply​. Such causes can be challenging to address (you can’t easily “fix” an entrenched attitude or an HR policy in an audit finding). The limitation here is not with the method per se, but the organization’s ability to take action on the identified cause. It’s important to acknowledge these cases and escalate them appropriately (e.g., to senior management or HR).

The 5 Whys has done its job in revealing the cause, but leadership may need to be involved to resolve it. In audits, if a root cause points to a cultural or management issue, it should be highlighted in the report as something needing top management attention.

Performing a thorough 5 Whys analysis takes time and careful thought. In a busy audit schedule or during an ongoing incident, there may be pressure to fix things quickly.

Allocating time for root cause analysis can be a challenge. However, not investing that time can lead to recurring problems that ultimately cost more time. One mitigation is to perform a quick preliminary 5 Whys during the audit or immediately after an incident (to guide immediate fixes), and then do a deeper follow-up analysis as a post-incident review or part of the corrective action phase. This way immediate containment isn’t delayed (you stop the bleeding) but you still commit to finding the underlying cure.

Management should recognize the value of RCA and make it a priority, so that auditors and analysts are given the mandate to spend time on it.

To overcome these challenges, organizations can take several measures: provide good training and even cheat-sheets for effective 5 Whys (emphasizing fact-based answers, going deep enough, etc.), encourage teamwork in analysis, and integrate other tools when needed.

If 5 Whys identifies one cause, a team might still review a quick checklist of other potential factors (human, technical, procedural, external) to see if any were missed. If 5 Whys suggests a cause that the team isn’t sure about, they can use data logging or a controlled test to verify if that cause really leads to the effect.

Awareness is the antidote to these limitations.

The 5 Whys is best used as a flexible framework within a larger problem-solving toolkit. Recognizing its weaknesses, an audit team can adjust – ensuring they ask the right people, seek evidence at each step, and don’t hesitate to use another method if the situation warrants. 

Conclusion and Recommendations

The 5 Whys methodology offers a straightforward yet powerful way for organizations to improve their cybersecurity posture through deeper understanding of problems.

Continually asking “why” and not settling for superficial answers, internal audit and security teams can uncover the true root causes of non-conformities, control failures, and security incidents.

This guide has shown that 5 Whys, originating from Toyota’s quality practices, is highly applicable to cybersecurity frameworks like ISO 27001, ISO 42001, NIST, and SOC 2 that demand continuous improvement and effective corrective actions.

When used properly, 5 Whys transforms an audit or incident response from a reactive check-box exercise into a proactive learning process. Teams move from fixing immediate issues to addressing the fundamental process or system weaknesses that underlie those issues – whether it’s a missing procedure, an oversight in risk assessment, or a breakdown in communication. Such insights are invaluable.

Identifying the underlying factors that contribute to incidents allows an organization to improve the effectiveness of containment and eradication efforts and decrease its vulnerability to future attacks.​

In other words, investing time in root cause analysis now pays dividends in future risk reduction.

However, it is equally clear that 5 Whys is not a one-size-fits-all solution. Complex cybersecurity challenges may require more elaborate analyses or a combination of techniques. A key recommendation, therefore, is to use 5 Whys as part of a broader toolkit.

For simple and moderately complex problems, 5 Whys might be all that’s needed – it’s quick, engaging, and often gets to a cause that can be fixed relatively easily.

For more complex issues, organizations should not hesitate to supplement the 5 Whys with other methods: for instance, use a fishbone diagram to map multiple cause streams (and even use 5 Whys on each stream), or use fault tree analysis if the situation warrants a detailed logical breakdown. The methods can be synergistic rather than exclusive​.

Combining approaches can overcome individual limitations (e.g. using data from Pareto analysis to decide which issue to apply 5 Whys on, or confirming a 5 Whys hypothesis with FTA). The ultimate goal is accuracy and thoroughness in understanding problems.

To successfully adopt 5 Whys in cybersecurity audits, organizations should also focus on culture and process. Encourage a culture where asking “why” is welcomed – this means leadership should support open discussions about things that went wrong, rather than discouraging inquiry.

When people are not afraid of blame, they are more likely to surface honest answers during a 5 Whys analysis. Also, integrate the practice into the formal processes: as mentioned, include it in audit workflows, incident response playbooks, and continuous improvement programs.

Over time, as teams repeatedly perform root cause analyses, they will become more adept and efficient at it. They will also accumulate a knowledge base of root causes and fixes (for example, noting that “lack of awareness training” has come up multiple times might signal a broader issue to management).

This organizational learning is exactly the kind of outcome frameworks like ISO 27001 envisage in their improvement clauses.

Another recommendation is to track and measure the effectiveness of your root cause analyses. After implementing a corrective action derived from a 5 Whys, monitor whether that issue recurs. If it doesn’t, that’s a success story you can communicate to reinforce the value of 5 Whys. If it does recur, it may indicate the root cause analysis missed something, providing an opportunity to refine the approach (maybe the team stopped too early or didn’t consider another branch of causes). This feedback loop will sharpen future analyses.

The “5 Whys” methodology, when applied with care, can significantly enhance internal audits and compliance efforts in cybersecurity. It aligns perfectly with the continuous improvement ethos of standards like ISO and NIST – turning every audit finding or incident into a chance to strengthen the system. With digging down to root causes, organizations avoid superficial fixes and instead implement changes that are more effective and permanent​.

The main takeaways and best practices for using 5 Whys in cybersecurity audits

  • Ask boldly, answer honestly: Don’t shy away from asking “why” multiple times – it may reveal inconvenient truths, but those are exactly what need to be addressed. Ensure answers are fact-based and focus on process/system issues, not individual blame​.
  • Integrate into your ISMS/Program: Make root cause analysis a standard part of your security management activities (audits, incident reviews, etc.) so that it happens consistently and not just ad hoc​.
  • Combine with other tools when needed: Use 5 Whys in tandem with visual or quantitative tools for complex issues – this mitigates its limitations and provides a more complete analysis​.
  • Train teams and foster collaboration: Equip your staff with the skills to perform RCA and create an environment where different experts can contribute, yielding a more robust analysis​.
  • Focus on continuous improvement: Treat the outcome of 5 Whys as inputs to improve policies, processes, and controls. Monitor the effectiveness of changes and share lessons learned. This creates a cycle of improvement where the organization continuously gets more resilient.

In cybersecurity the ability to learn and adapt is perhaps the greatest benefit of all. Every “why” asked is an investment in making the organization stronger and more secure.

As the experience of many quality and security programs has shown, persistent questioning of “why” ultimately leads to clarity – and clarity drives effective action and enduring security improvements.​

FAQ

The 5 Whys is a root cause analysis technique originally developed in the Toyota Production System. It involves asking “Why?” repeatedly (typically five times) to dig deeper into a problem until the underlying cause is uncovered, moving beyond superficial symptoms to address the core issue.

In cybersecurity audits, the 5 Whys helps uncover the root causes behind non-conformities or security incidents. Instead of simply fixing a symptom (like a misconfigured firewall), the method prompts teams to explore underlying issues—such as process gaps or training deficiencies—leading to more effective and lasting corrective actions.

Frameworks that emphasize continuous improvement and root cause analysis benefit greatly, including ISO 27001 (2022), ISO 42001, NIST, and SOC 2. These standards require organizations to identify underlying causes of issues and implement corrective actions, making 5 Whys an ideal tool.

While the 5 Whys is simple and fast, other methods like Fishbone Diagrams, Fault Tree Analysis (FTA), and Failure Mode and Effects Analysis (FMEA) offer more detailed frameworks for complex problems. The 5 Whys is excellent for a quick, linear investigation, whereas tools like Fishbone allow for exploration of multiple contributing factors simultaneously.

Yes. Often, organizations start with the 5 Whys for a quick investigation and then supplement the analysis with tools like Fishbone Diagrams or FTA for a more comprehensive view. Combining methods can help capture multiple cause streams and ensure no critical factor is overlooked.

ISO 27001 Internal Audit Checklist
ISO 42001 Internal Audit Checklist