Manufacturers who have production capacity constraints, or struggle to understand where they lose capacity, can use Root Cause Analysis (RCA) to thoroughly investigate downtime incidents, and implement targeted corrective actions that lead to long-term improvements in productivity, cost savings, and equipment reliability.
This article looks at Root Cause Analysis, with a focus on how it can be used to identify the symptoms and remove altogether the causes of machine downtime.
Root Cause Analysis (RCA) is a systematic approach used to identify the underlying cause of a problem rather than just addressing its symptoms. In manufacturing, RCA is a critical tool to support a Lean manufacturing production method, as it is used for diagnosing and eliminating the causes of an issue, for example, machine downtime, thus improving efficiency, and preventing recurring issues.
RCA isn’t about searching for problems—it’s about understanding them. The process often highlights underlying inefficiencies or risks that might have otherwise gone unnoticed, enabling teams to address multiple issues at once and drive broader improvements.
By embedding Root Cause Analysis (RCA) into daily operations, teams develop a consistent, structured approach to tackling issues. While every problem has its nuances, RCA ensures a systematic and repeatable method for identifying and resolving challenges across departments.
Teams that regularly use RCA develop a habit of questioning why issues occur and how they can be prevented. This mindset fosters a culture of continuous improvement, enhancing operations, safety, maintenance, and quality across the organisation.
When one department successfully applies RCA, its insights and best practices can be shared across the business. By leveraging data and learnings from each analysis, teams can collaborate more effectively to solve problems and drive company-wide improvements, this is especially effective in organisations that have a culture of continuous improvement.
By tackling the root cause rather than just the symptoms, RCA helps prevent recurring issues that drain time and resources. This approach minimises unplanned downtime, reduces defects, and streamlines processes—ultimately improving efficiency and profitability.
Manufacturers that use RCA to reduce machine downtime can experience significant operational benefits, including:
Conducting an effective RCA involves a structured, step-by-step approach. Below is a framework for using RCA to diagnose and resolve machine downtime issues in manufacturing.
Clearly outline the issue by gathering key details such as:
Gathering accurate data is essential for diagnosing the root cause. This includes:
Use analytical tools to explore potential causes. Three effective methods are: A downtime Pareto analysis, The 5 Whys and a Fishbone diagram. We explore each of these in more detail below.
A Pareto Chart is a valuable tool for performing Root Cause Analysis (RCA) on downtime, as it helps prioritise the most significant factors contributing to the issue. Based on the 80/20 rule, it visually highlights the few key causes that account for the majority of downtime, allowing teams to focus on solving the most impactful problems first.
Collect Downtime Data
Sort Causes by Impact
Create the Pareto Chart
Identify the Key Contributors
Prioritise RCA Efforts
The '5 Whys' is a simple but effective questioning technique that helps drill down to the fundamental cause of a problem.
Example:
Root Cause: Lack of scheduled maintenance leading to overheating issues.
A visual tool that categorises potential causes into different groups such as:
This method helps teams systematically identify and categorise all possible contributing factors.
Step 4: Verify the Root Cause
Before implementing solutions, validate the root cause by:
Step 5: Implement Corrective Actions
Once the root cause is confirmed, apply appropriate solutions such as:
Step 6: Monitor and Continuously Improve
RCA should not be a one-time activity. To ensure long-term improvements:
Challenge: A manufacturer experienced frequent unplanned downtime on its CNC machines, leading to production delays and high maintenance costs.
Problem Defined: Machines frequently stopped due to spindle motor failures.
Data Collected: Maintenance logs showed repeated overheating incidents. Machine downtime logs showed how many hours of downtime had been lost because of breakdowns.
Analysis: 5 Whys: Overheating was traced to clogged air filters, which were not being cleaned regularly.
Root Cause Identified: Lack of scheduled filter cleaning caused airflow blockages, leading to overheating and eventual motor failure.
Solution Implemented:
Root Cause Analysis is an essential tool for manufacturers looking to reduce downtime and improve operational efficiency. By systematically identifying and eliminating root causes, manufacturers can enhance productivity, reduce costs, and create a more reliable production environment.
For companies seeking a proactive approach to downtime reduction, machine monitoring systems like FourJaw provide real-time visibility and actionable insights, making RCA more efficient and data-driven.