Product lot and box sequence number assigned from production

I would like to know what is the correct approach to handle the value of the lot and the package sequence inside the warehouse. This is applied to a manufacturing company that produces a product “on order” (aka. à la carte) by the customer and is identified with a production order number. This production order number later becomes the lot number for that inventory. Before the product is moved to the warehouse, it is packaged in the manufacturing plant in separate boxes of equal quantity and each box is labeled with the lot number and a box sequence number. Both lot and sequence number is needed for traceability. The lot is for the raw materials, the box sequence number is for operator and machine traceability. The box sequence is restarted back to 1 for each new lot number.

Once the product is moved to the warehouse, the boxes are store in pallets ready to be shipped. No additional packing is needed. From there the customer can decide how the product is delivered: ship the entire lot in one shipment or make 2 or 3 partial shipments scattered in 4 to 6 weeks of time, For each delivery a packing list is generated with information about the lot number and the box sequences present for that particular delivery. Box sequences marked as delivered in a previous partial shipment will not show up as available on the next shipment.

Is there a solution in Tryton that can do this use case? Can it be done using the current modules: stock_lot, stock_split?

For me you just need to set a lot sequence on the produced products and divide the production into 2 productions. One that output the raw material which will have its own lot sequence and then a second that produces boxes (which is another product) with also its own lot sequence.
With the lot traceability you would be able to find from the box lot the corresponding raw product lot used.

As you want to have a lot per box, you will need to activate stock_lot_unit to be sure to have a unique lot per unit. And you will need stock_split to create an output move for each unit of the production.

Maybe I did not explain well the situation with the lot and box sequence number. Both number are used only to identifying the product, the box itself is not a product produced in the plant. We can think of the final lot number as a concatenation of 2 numbers: <production number>-<batch sequence>, where:

  • production number is the production order number that identifies the source materials used in BOM
  • batch sequence is the sequence that counts each portion of the product coming out of the production line. The manufacturing of the product can take several days or weeks, therefore there are many operators and possible many machines (when produced in parallel) from different work shifts. Each portion is package in a box and assigned this batch sequence and the personnel from quality assurance uses this sequence to relate this portion of the product to the operator and machine that produced it.

One way to solve this is to take this <production number>-<batch sequence> as the lot number in Tryton. But this will generate too many lot numbers in the system and may be inconvenient to manage. However, in following this approach, one way to ease having too many lot numbers is to allow grouping the lot numbers by the prefix <production number> and display that in the lot list. Only when we want to select specific batch from that production number, we expand and show all the batches from the same production number.

Regarding the stock_lot_unit and stock_split, when applied to the use case in discussion; would it be that the lot per box (or batch sequence) be generated only at the moment of packing and shipping to the customer. But I need this lot per box to happen at the manufacturing process, even before the product is stored in the warehouse.

Then it is not one production but multiple production with each one a lot number.

Yes, we can think of it as a multiple sub-productions of a parent production, and somehow find an elegant way to relate these lots per box to the same parent production.