Die kurze Antwort
Assembly builds one thing from many. Disassembly splits one thing into many, sorted into grades. Cost follows the yield: when the good grades shrink, the cost does not disappear, it moves to the bad ones unless you decide otherwise.
A bill of materials, run backwards
A standard bill of materials says: take these parts, make that product. A butcher, an oil refiner and a scrap processor have the opposite problem. They take one input and split it into several outputs, and the interesting question is what each output cost.
- A carcass becomes cuts: primal pieces, trim, bone and fat.
- A crude oil becomes fractions, each with a different value.
- A tank of scrap becomes sorted material, some saleable and some not.
In each case the input is bought as a lump, the outputs come out in proportions that vary from run to run, and finance needs a cost per output. Disassembly in ManufacturingFlow 365 is built for this shape, which standard production orders, with their one-item output, are not.
Grades, not just items
The outputs of a disassembly are usually graded. Cuts come out as premium, standard and trim. Fractions come out as grade A, grade B and a residue. The grade matters because it drives value, and value is often what the cost is shared on.
Our demo scenario is a crude-oil disassembly with three outputs: grade A, grade B and sludge. Each is posted as an output against the order. Sludge is the interesting one, because it is the part that most systems do not know what to do with.
How cost follows yield
Illustrative figures chosen to show the arithmetic; they are not customer data and not from our test runs.
Take 1,000 litres of crude costing 10,000, so 10.00 per litre. Plan for 600 litres of grade A, 300 litres of grade B and 100 litres of sludge. Share the cost by physical measure, which is the simplest of the four allocation methods, and each litre carries 10.00.
| Output | Planned litres | Planned cost | Actual litres | Actual cost |
|---|---|---|---|---|
| Grade A | 600 | 6,000 | 500 | 5,000 |
| Grade B | 300 | 3,000 | 300 | 3,000 |
| Sludge | 100 | 1,000 | 200 | 2,000 |
| Total | 1,000 | 10,000 | 1,000 | 10,000 |
The run was poor: grade A fell by 100 litres and sludge doubled. Total cost is unchanged at 10,000, because the crude was bought once. But the sludge now carries 2,000 where it carried 1,000, and the saleable grades carry 1,000 less between them. A poor yield does not make the input cheaper. It moves the cost into the output you cannot sell.
That is also why physical measure alone is a blunt tool here: it prices a litre of sludge the same as a litre of grade A. Allocating by relative sales value or net realisable value tells a different story, and the four methods are compared on one batch in a sibling article.
The tank of scrap
Waste is where disassembly costing usually goes quiet. The sludge, the off-cut, the unsortable fraction is a real output of the process. It was made from costed input, it took machine time, and it may cost money to dispose of.
ManufacturingFlow 365 records waste as an output with its own cost, rather than as a quiet loss against the good grades. That has two effects. The cost of the good outputs is not inflated by absorbing waste invisibly. And the cost of waste is visible, so a plant can see what it is worth reducing the sludge by a few litres. A recycler dealing in mixed scrap has the same question in different clothes: how much of the load became saleable material and how much became residue.
A useful habit is to review the waste line of every run next to the grades. If sludge doubles, as in the table above, the cost sheet shows it on the day, not at month end when the stock has been sold and the cause has gone cold.
Evidence that holds up
Disassembly runs often feed products that are traded, labelled or audited. Batch operations in ManufacturingFlow 365 come with an electronic batch record and audit trail, so there is a record of what went in, what came out and what changed. This supports traceability and audit trails; it is not a claim of compliance with any regulation.
In Business Central
- Disassembly with grades under batch operations, for example carcass to cuts or crude oil to fractions.
- Outputs posted against the order, with joint cost allocated four ways: fixed percentage, relative sales value, net realisable value or physical measure.
- Waste recorded as an output with its own cost.
- Electronic batch record and audit trail.
- Lot genealogy forwards and backwards.
- A crude-oil disassembly scenario with grades A, B and sludge in the demo data.
Limits
The table above is illustrative arithmetic and uses physical measure only for simplicity. ManufacturingFlow 365 is designed from 63 identified gaps, of which 27 are implemented and 36 partly. Exports and some planning pages have not been run. Electronic batch record, e-signature and change approval have not been tested with a second user. The apps have been run in a UAT sandbox with demo data and no live customer is recorded. Check that the grades and the reverse structure you need are covered by running your own input through the scenario.
See it on your process
Tell us what you split and how you grade it. We will run it through a disassembly in the sandbox: book the crude-oil disassembly scenario.
Keep reading: co-product, by-product or waste and yield, mix, usage and price variances.