Root Cause Analysis: What It Is, How to Do It, and Examples That Work

When problems keep resurfacing, such as missed deadlines, repeated bugs, and breakdowns in communication, it’s often because the sources of those issues haven’t been addressed. Reacting to what’s most visible wastes time and leaves teams fighting the same fires sprint after sprint instead of building. Root cause analysis (RCA) is a structured way to identify what triggered the problem and fix it at the source, so the same issue doesn’t keep coming back. 

What is root cause analysis?

Root cause analysis is a structured approach to figuring out why a problem happened. It breaks complex issues into contributing factors and identifies the primary cause so you can address the source directly.

A symptom is the visible problem, such as a customer complaint. You want to find the root cause, or the condition that made it possible, such as a gap in quality assurance.

RCA combines process thinking — looking at how the process functions as a whole — with practical techniques. Using language such as “the process failed here” keeps the investigation centered on what can be changed instead of who should be blamed.

When to use RCA

Use root cause analysis when a problem keeps happening or when a single failure reveals bigger risks.

• Recurring project issues. Missed deadlines, handoff problems, or unclear requirements keep resurfacing across projects or sprints.
• Product defects. Bugs reappear in multiple releases or customers repeatedly flag the same issue.
• Process breakdowns. Delayed approvals, missed tasks, or gaps in workflows consistently interrupt progress.
• Team friction. Role confusion or communication gaps slow work or hurt morale.
• Customer complaints. Patterns in feedback point to a systemic problem in onboarding, support, or the product experience.

Benefits of root cause analysis

RCA can also strengthen your business process management steps by showing where a process needs targeted changes. 

• Reduces repeat problems. Fixing the source keeps the same issues from coming back in the next sprint, release, or quarter.
• Accelerates resolution. A shared view of the cause makes it easier to take targeted action.
• Improves long-term processes. RCA helps you spot friction in workflows, roles, or tools so you can make better decisions next time.
• Creates a culture of continual improvement. Over time, RCA builds habits of curiosity, accountability, and consistent follow-through.

Root cause analysis methods

You can approach RCA in different ways depending on the problem, its complexity, the available data, and who’s involved. Some methods work well for quick checks. Others help you break down more complex issues.

The five whys

This method starts with a simple question: Why did this happen? You keep asking “why” in response to each answer until you reach the root cause.

1. Write down the problem clearly.
2. Ask why it happened without assigning blame.
3. Take that answer and ask why again.
4. Repeat until you reach a cause your team can act on.
5. Agree on what needs to change to prevent recurrence.

Best for: Straightforward problems you can discuss in real time with limited data, including issues raised during a scrum meeting. Although five rounds is common, stop once you reach something concrete your team can fix.

Fishbone diagram

A fishbone diagram, also known as an Ishikawa or cause-and-effect diagram, maps possible causes by category. It gets its name from its shape, which resembles a fish skeleton.

1. Write down the problem at the head of the fish.
2. Draw branches for categories such as people, process, environment, and tools.
3. Add possible root causes under each category using observations rather than guesses.
4. Discuss each branch using real data or recent examples.
5. Identify the most likely cause and decide what to do about it.

Best for: Complex issues involving multiple teams, tools, or workflows. Its branching structure is similar to the approach used when learning how to create a mind map.

Fault tree analysis

Fault tree analysis uses a logic diagram to show how smaller failures may have combined into a larger one.

1. Start with the failure at the top of the diagram.
2. Branch downward with possible causes, using “and/or” logic.
3. Break each cause into more specific contributing factors.
4. Validate each branch with data or system logs.
5. Work back to the lowest cause that is still within your control to fix.

Best for: High-stakes or safety-critical situations where you need to examine failure chains in detail. The method builds on the branching logic used in flowcharts 101. 

Pareto chart

A Pareto chart helps you prioritize which problems to address first. It’s based on the 80/20 principle, the idea that a few causes often drive the majority of problems.

1. List the problems or causes you’ve observed.
2. Count how often each one occurs.
3. Sort them from highest to lowest frequency.
4. Create a bar chart with causes on the X-axis and counts on the Y-axis; add a cumulative line graph.
5. Focus on the causes at the front of the chart, which are the highest-impact problems to fix first.

Best for: Recurring issues that need to be ranked by frequency and impact. This approach complements the best methods for prioritizing tasks and projects at work.

Scatter diagrams and control charts

Scatter diagrams show the relationship between two variables, such as call volume and response time. Control charts track a process over time to show when variation falls outside expected limits.

1. Choose the variables you want to compare.
2. Plot the data in a spreadsheet or analytics tool, which signals whether the process is stable.
3. Look for clusters, gaps, or outliers.
4. Investigate what changed when a spike or drift appears.

Best for: Data-heavy environments where you need to distinguish random variation from a systemic trend.

None of these methods will find the solution for you, but they can help you ask smarter questions and focus your investigation.

How to conduct a root cause analysis

Here’s a step-by-step guide on how to walk through a root cause analysis:

Step 1: Define the problem clearly

Write a specific problem statement that covers what happened, where, and when. Don’t start by assuming you know the cause. A precise statement keeps the team from investigating or solving the wrong problem.

Step 2: Collect data and evidence

Gather anything that helps you see what led to the issue, including logs, metrics, ticket history, stakeholder input, and corporate meeting minutes. Collect a broad range of evidence before narrowing the investigation so missing context doesn’t lead to an incomplete finding.

Step 3: Identify contributing factors

List anything that may have played a role, such as unclear instructions, missed handoffs, tool outages, workload changes, or process gaps. Use the five whys or a fishbone diagram to break these factors down, and look for patterns across multiple incidents.

Step 4: Determine the root cause

Look for the factor that triggered the rest. Ask if fixing it would have prevented the issue. Complex problems may have several contributing factors, so don’t stop at the first plausible cause. If you can’t act on the answer directly, keep digging.

Step 5: Develop and implement solutions

Translate the root cause into a specific, time-bound action. That could mean updating a process, shifting responsibilities, improving documentation, or changing how tools are used. Assign a clear owner for each action; a RACI model can clarify who is responsible and accountable.

Step 6: Monitor results and prevent recurrence

Watch what happens after the fix. Does the issue return? Has something new cropped up? Set a date to review progress and keep the feedback loop open. Connecting RCA to an agile methodology can make each investigation more useful to the next cycle of work.

Root cause analysis example

Say your team keeps missing client report deadlines. At first, the reasons seem varied: someone’s out sick or last-minute edits take longer than expected. After the third delay in a row, the team decides to investigate instead of treating each miss as a separate problem.

Using the five whys, the analysis might look like this:

1. Why was the report late? Final edits weren’t completed before the deadline.
2. Why weren’t they completed? Feedback arrived after the report had been assembled.
3. Why did late feedback delay delivery? No one had authority to close edits at a set cutoff.
4. Why was there no cutoff owner? Individual tasks had owners, but final delivery did not.
5. Why was the final delivery unassigned? The reporting process never established a single point of accountability.

The team now has a specific root cause it can address. As part of its project roadmap, it assigns a report lead to own final delivery and catch preventable issues earlier.

• Before: Each delay feels like a one-off, and no one sees the pattern.
• After: One person owns delivery, and reports start going out on time.

The power of RCA is not just identifying the cause, but making a process change that removes the conditions that allowed the problem to keep happening.

How Slack supports root cause analysis

The right tools can make the process faster, more organized, and easier to share. These resources from Slack do just that:

• Dedicated channels and threads. Create a channel or thread for each RCA to keep context, data, and decisions in one searchable place. After an incident, tag teammates to fill in gaps without waiting for another meeting. The conversation also creates a record you can revisit if the problem returns.
• Huddles for live analysis. Start a Slack huddle when the team needs to talk through findings in real time. A live conversation can help people ask sharper questions, resolve conflicting accounts, and agree on the next step.
• Workflow Builder for a repeatable process. Use Workflow Builder to standardize how you collect information after a problem or trigger follow-up once the root cause and corrective action have been documented.
• Integrations for connected context: Connect project trackers and issue-management tools to Slack so evidence and resolution steps remain accessible. You can also schedule automated check-ins to surface assigned actions before the review date.

RCA works best when it is a team habit, so start with recurring problems where the pattern is already visible, then build RCA into the processes you use to document issues and follow through on fixes. 

To explore how Slack could support that process, talk to sales.

Root cause analysis FAQs