Root cause, correction & preventive actions…
What is a non-conformity?
A non-conformity is when something does not comply with the set standard. This may result in a quality, legal or food safety issue.
The non-conformity has an effect…
A non-conformity means a particular standard has been affected. The standard which is not being adhered to (or complied with), may be:
- The specification of the:
- Finished product
- In process materials/product (factory specification)
- Standards for cleaning
- Standards for testing, such as micro or chemical analysis
- Quality standards on the line – such as quality checks
- Legal standards on the line – such as average weight checks
The non-conformity can come from a number of sources…
A non-conformity can arise from a number of situations, or come from a number of sources, such as:
- Complaints or incidents (because the specification hasn’t been adhered to)
- Factory checks, such as on-line checks, which identify that the product or material is non-conforming
- Routine evaluations, such as environmental testing results
- System checks following cleaning or maintenance etc.
- Internal audits
- External or third party audits
- Trending and management reviews
What is the difference between corrective and preventive actions?
A correction or corrective action, fixes the current issue – there and then.
A preventive action, fixes the root cause of the problem – ensuring that it doesn’t happen again.
The root cause is the reason why a non-conformity arose in the first place. The root cause: is what caused the effect to occur (cause and effect). You can think about that visually, through the picture of this tree.
Normally, you can’t see the root system of the tree because it’s underground. You only know that there is something wrong with the tree, when the leaves begin to go brown and die. The leaves going brown and dying is the effect; the result of whatever is wrong with the tree. Pulling off the dead leaves will correct the problem – there and then, but it won’t stop the rest of the leaves going brown. And, ultimately the tree will die, if the cause of the problem is not found.
The cause can only be found, by looking at the root system of the tree. By finding out what the root cause of the problem is…
How to work out what the root cause is…
There are a number of known analysis methods, which help you to establish what the root cause may be, such as:
- Fishbone diagram
- 5 whys
- Fault tree
A Fishbone diagram, is where the effect (the non-compliance is written by the fish head) and then the causes are brainstormed and written for each of the following headers:
This system helps you to ensure that you’ve thought about all the possible causes, before you then go to work out which one(s) are the real root cause. If you’d like a copy of our Fishbone diagram, you can get one here as a subscriber to access our downloads page.
The 5 why’s is used to ask the question ‘why?’ – to each answer you give. Although it’s called ‘5’ why’s – that doesn’t necessarily mean you’ll need to answer why, exactly 5 times – it may take less, it may take more. The idea is to keep going until you can’t answer anymore.
The idea of the fault tree, is to think of all the things that may be at fault (the cause). For each fault – you then try to work out what caused that fault. Then you work out what caused that fault, again and again – until you cannot answer any more. Very similar to the 5 why’s system.
When do you know enough, is enough? When do you know you’ve got to the true root cause?
Not reaching root cause, is a very common issue that I see while auditing. It’s so important to make sure you truly get to the root cause of the problem, otherwise you’re at risk of spending time on actions which don’t really cut the mustard! Meaning, you have to correct the same problems over and over again – which is a false economy.
The best way to ensure you’ve got to root cause is for you/ your team to be honest with yourself. Imagine that in 6 months’ time from now, you’ve had a recall, due to the very non-compliance you’re assessing for root cause now. Ask yourself, if you were called in and challenged by your senior manager, as to whether the root cause that you implemented (the one that you’re proposing now) is sufficient – in that situation, would you feel comfortable defending yourself and your team, that you’ve truly identified and rectified the root cause?
Typically, I find that root cause can normally be traced back to one or more, of the following reasons:
- Training is insufficient or ineffective
- An error or an emittance from the procedure or system
- Management commitment – due to lack of resources (money, people etc.)
- A unknown, unknown – for example, the business not having the required skills or knowledge to the do the ‘right thing’
If your root cause(s) meets at least one of these points, I think you’re probably going in the right direction.