Rework is a defective product that can be repaired and sold to the customer
I am quite confident that you are aware about the definition , but are you also aware about how much money this rework costs you
I have seen many companies not only in Egypt but also (ironically) in Europe , that treat rework like a minor inconvenience. They deal with it with the mindset of “ It’s just a small fix”
What if this small fix happens everyday , so it will be multiplied by 20-25 every month and around 300 per year, this is with an assumption of one small fix everyday , of course it will depend on the industry but the mindset itself is very dangerous
Why rework is that dangerous
Rework Reduces Production Output, Every time you rework a unit, you’re using time and capacity that could have gone to making something new. It also disrupts planning reliability, imagine that you are a planner and you don’t know how many good products you will get at the end of the day or when you will have them, so your proactive actions would be planning more and creating more inventory.
Rework increases labor cost as you will need more labor hours and in some extreme cases you need extra labor, it might also occupy machines ,not to mention wasting materials form product components to labels and other packaging material.
And last but not least , it will affect customers whether through delays or the product performance , in the Six Sigma literature , Before General Electric adopted the Six Sigma approach , they had a study that the reworked devices were having lower performance in the market.
So , it is not only a quality problem , it is a financial one.
The invisible costs of rework
The problems above might be clear for everyone ,but there are other costs that a lot of factories don’t consider or ignore.
What about your people, do you think they like repairing the product they produce , what about fixing the same issue over and over again , that may lead to frustrations as it feels like punishment , destroys pride in work ,and in many cases creates internal conflict between production and quality
Moreover , it will create a habit so when it happens no one will report it , and here I am talking about reporting the problem , seeing it as a problem not fixing the product , and this will kill the continuous improvement culture .
How to reveal the true cost of rework
Track Rework Cases
Create a log for rework cases , record the product , the lot , the shift , the defect and the time spent to fix it .
Assign Time and Material Cost
That could be an estimation based on the labor hour cost and the cost of the item used to repair .
Summarize Weekly & Monthly Totals
Don’t just measure how many rework units were created , include total time lost, labor and machine costs , and waste in materials.
Investigate
Once you have the numbers, start to dig deeper to identify the root causes for the most contributing defect(s) .
Improve
Take actions to eliminate the root causes and measure the improvement .
Final Thoughts
In manufacturing , I believe in the quote that says “what is not measured cannot be improved”, and rework is a great example for this quote. If you don’t measure it, you won’t fix it. If you don’t fix it, you’ll keep paying for it .