The quarantine bin is full again
There is a red bin by the inspection bench. It fills up with parts: undersized bores, a face with chatter marks, a thread cut too deep, a batch where the fixture slipped. Some get reworked, some get scrapped, some sit there for weeks while someone decides.
At the end of the month, the scrap merchant takes a skip of swarf and scrapped parts. The material cost goes into the general material line. The machine time that made those parts is never counted at all.
Why scrap stays invisible
Scrap is embarrassing, and recording it takes time the operator would rather spend making the good part. Unless it triggers a customer complaint, it tends to go in the bin without a word. Rework is even harder to see, because the part eventually ships.
- Scrap is not recorded, or is written on the job card without a reason.
- Parts scrapped at the last operation cost far more than those scrapped at the first, but are counted the same.
- Rework time is booked to the job as normal running time.
- Setup pieces and prove out parts are mixed in with genuine scrap.
- Nobody reviews scrap by cause across jobs.
What you are not seeing
A part scrapped at final operation carries the material, every previous operation's machine time, and the time to make its replacement, which may push the job late. Across a year, repeated causes such as a worn fixture, an unreliable probe or a program that relies on the setter's touch add up to real money that is hidden in your overheads. Without numbers, you cannot justify fixing them.
The scrap and rework log we build
- At each machine or cell, a tablet takes a scrap or rework entry in a few taps: scan the job, choose the operation, choose a reason from your list, enter the quantity, and optionally take a photo.
- Reasons are yours and short: dimension out, surface finish, damage in handling, material defect, setup piece, program error, fixture movement, and so on.
- Each scrapped part is costed at the stage it was scrapped, using material cost and the operations it had already been through, at your machine rates.
- Rework is recorded with the time spent, so the job's true cost includes it.
- The job's required quantity is checked against good parts, and the planner is warned if a remake is needed to meet the order.
- Weekly reports show scrap and rework cost by part number, customer, machine, operation and reason.
| Scrapped at | Cost includes |
|---|---|
| Saw | Material only |
| First operation | Material and first operation time |
| Second operation | Material and both operations |
| After outside processing | Material, operations and processing charge |
| Final inspection | Everything above, plus remake time |
Setup pieces and prove out parts are recorded separately, so they do not hide genuine scrap and are not counted against the operator.
What the numbers change
For the first time, scrap has a figure you can compare month to month and a list of causes ranked by cost. That list usually points to a few parts and a few causes. Fixing a worn fixture or rewriting one program becomes an easy decision once you can see what it has been costing.
Quotes for parts with a history of scrap can carry an honest allowance, and the planner hears about remakes the same day instead of at dispatch.
Is scrap hiding in your overheads?
- Nobody knows last month's scrap cost.
- The quarantine bin fills with undecided parts.
- Remakes are discovered at dispatch.
- Rework time is not recorded.
- The same parts seem to cause trouble every time.