If your manufacturing company develops a problem along the way with one of your processes, how do you resolve it? While the shortcut option is to simply patch up the symptoms of whatever that problem may be, the long-term solution is to perform an RCCA process.
By utilizing this root cause and corrective action process, your manufacturing organization strengthens its internal and external procedures by getting to the heart of the problem rather than managing the consequences of it. But what is RCCA, and how can you implement it in your organization? This comprehensive guide has everything you need to get started!
RCCA is a process used to systematically analyze a problem to determine its underlying causes. It leads to identifying the cause and effect relationship in the manufacturing process.
Rather than point blame for mistakes to people, RCCA aims to analyze each step of a procedure to truly understand where errors might arise, track patterns, and more.
Your manufacturing organization should perform RCCA as part of a corrective action plan, or when not performing one could impact your levels of customer quality, delivery, or satisfaction. Some large customers often make it a mandatory part of their business; for example, Toyota's RCCA is recognized best-in-class in the automotive industry.
Quality problems should always be solved as a team; gather the process experts who should assist with this problem and who have a wide variety of skills and knowledge to provide different perspectives.
The RCCA process generally follows these steps:
Before diving into each step, however, it’s important to apply a systems-thinking approach to the overall process.
Many times, due to time and schedule pressure, and other factors, it seems easier to solve a problem by treating the symptoms, not the root cause. However, the same problem will recur - and if Murphy’s Law has anything to say about it, at the worst possible time. Over time, unresolved root causes build-up resulting in a situation where one is jumping from one crisis to the next. It quickly becomes a rather ineffective and inefficient situation.
Instead, try to use a systems-thinking approach by listing all the factors that created the situation, consider the bigger picture, elicit perspectives from others, and truly seek to understand the weakness in the process. This approach is slower and more methodical but is well worth the effort to fully understand the manufacturing process and reduce the number of “fires” to fight over the long-term.
Below is an overview of each step of the RCCA Process:
The Problem Statement should:
The Problem Statement does not:
Essentially, you should be able to define the who, what, when, where, and how of the problem!
'Going to Gemba' is the act of visiting the shop floor in Lean. Translated as 'The Real Place', it pushes the importance of leadership understanding what is happening at every level.
This entails:
Part of this also includes interviewing the process users, such as floor personnel, production leads, supervisors, customers, and suppliers to review procedures, methods, activities, and tasks.
Once you can define the problem, you and your team need to establish why it happened. This step incorporates gathering all the facts of the situation and processing them to determine causal relationships. This will point you in the direction of the root cause of the problem!
Such factors to consider include:
After acquiring the aforementioned facts and context of the problem, state the potential cause(s) of the non-conformity and list all the tasks involved in the particular manufacturing process. Formulate a theory of root cause and designate how information - due date, days, tally, total, etc. - will be objectively recorded.
Review these records; what does this information tell you? Can you identify potential causal factors? Which qualities are leading to the problem - work environment, workflow, lighting, personnel training, distractions, or something else?
To "stop the bleeding", you’ll need to establish containment actions. This might entail changing equipment, re-training operators, and switching material suppliers. Short-term containment ensures the customer is protected from being immediately affected by the problem; it’s not a long-term solution, nor does it count as the problem having been resolved.
Next, select and implement the appropriate long-term corrective action solution. There might be several solutions available to you; be sure to choose the solution that:
From these factors, identify the best solution by ranking them and assigning importance to each possible path. This will help objectively determine the best course of action for your manufacturing team.
After selecting the best solution, you need to implement these changes! Start by dividing the solution into sequential tasks and create an action items list with responsibilities and due dates assigned to each pertinent team member. Be sure to have a contingency plan, however, and ask yourself what could go wrong, how you’ll know something has gone wrong, and what could be done to prevent it? Such questions aren’t pessimistic - in fact, they demonstrate taking initiative and actively engaging with the RCCA process!
Monitor the problem to ensure that the nonconformance does not reoccur. If it does reoccur, reject the root cause, then implement an alternate solution. Always determine if the nonconformance affected the product elsewhere in the organization, or if any nonconforming product was shipped to the customer. You’ll want to resolve that with them as soon as possible!
Allow sufficient time for the problem to reoccur to determine you properly addressed it. The problem might not reappear for a couple of weeks, for example, but that doesn’t mean it won’t return if the chosen corrective actions aren’t enduring. Verify that the identified problem has been addressed and it no longer occurs; there’s no official time limit, but your solution must work consistently.
Revise existing documents with the new solution; be sure to revisit:
These quality tools can help your manufacturing organization improve your RCCA process:
A histogram is a graphical representation that organizes a group of data points into user-specified ranges. Similar in appearance to a bar graph, the histogram condenses a data series into an easily interpreted visual by taking many data points and grouping them into logical ranges or bins.
Brainstorming is a group creativity technique by which efforts are made to find a conclusion for a specific problem by gathering a list of ideas spontaneously contributed by its members. Your employees can provide valuable insight into the manufacturing process, so gathering their input along the way of your RCCA process is important.
Control charts, also known as Shewhart charts or process-behavior charts, are a statistical process control tool used to determine if a manufacturing or business process is in a state of control. In other words, it’s a graph used to study how a process changes over time.
A scatter plot is a type of plot or mathematical diagram using Cartesian coordinates to display values for typically two variables for a set of data. This method of organizing data can reveal any present correlations between variables.
Pareto analysis is a formal technique useful to graphically represent the impact of various causes. They are based on the Pareto Principle, also known as the 80/20 rule. According to the Pareto Principle, over time, roughly 80% of the defects for instance will come from 20% of the causes. So by gathering and charting data, you gain visibility of the causes that will have the greatest impact - by doing 20% of the work, you can generate 80% of the benefit of doing the entire job.
Check sheets are not complicated to create. But oddly, they are probably the least used and most valuable of the Quality Tools. A check sheet is a form used to collect data in real-time at the location where the data is generated. The data it captures can be quantitative or qualitative. When the information is quantitative, the check sheet is sometimes called a tally sheet.
A process flow diagram (PFD) is a diagram commonly used in chemical and process engineering to indicate the general flow of plant processes and equipment. The PFD displays the relationship between major equipment of a plant facility and does not show minor details such as piping details and designations.
Sometimes referred to as a fishbone diagram, cause and effect diagrams are a visual tool used to logically organize possible causes for a specific problem or effect by graphically displaying them in increasing detail, suggesting causal relationships among theories.
Ask "Why?" at least 5 times; stop when going further adds no more value. When done, add the word "so" or "therefore" at the end of each response and then work backward, to the top of the page, to confirm the logic.
For example: Why Did the Lights Go Out?
A SIPOC (Suppliers, Inputs, Process, Outputs, Customers) diagram is a tool used by a team to identify all relevant elements of a process improvement project before work begins. It helps define a complex project that may not be well scoped and is typically employed at the Measure phase of the Six Sigma DMAIC (Define, Measure, Analyze, Improve, Control) methodology. It is similar and related to process mapping and ‘in/out of scope’ tools, but provides additional detail.
Failure mode and effects analysis is the process of reviewing as many components, assemblies, and subsystems as possible to identify potential failure modes in a system and their causes and effects. It’s a systematic and proactive method for evaluating a process to identify where and how it might fail, and to assess the relative impact of different failures, thereby identifying the parts of the process that are most in need of change.
A defect concentration diagram is a graphical tool that is useful in analyzing the causes of the product or part defects. It’s a drawing of the product, with all relevant views displayed, onto which the locations and frequencies of various defects are shown.
This is a method developed at Ford Motor Company used to approach and resolve problems, typically employed by quality engineers or other professionals. Focused on product and process improvement, its purpose is to identify, correct, and eliminate recurring problems.
There are 8 disciplines of problem-solving:
RCCA supports quality improvement by promoting a problem-solving culture of team communication, which results in behavior change and stronger company culture. People learn to address the "root causes" and not the symptoms. This line of thinking promotes deeper employee engagement and overall empowerment among your employees!
CMTC offers technical assistance, workforce development, and consulting services to small and medium-sized manufacturers (SMMs) across California to help SMMs increase their productivity and global competitiveness. For more information about CMTC, visit our website at www.cmtc.com or contact us at 310-263- 3060.