Fertigungsproblem bei Chiphersteller

11. März 2019 14:54


ich hoffe mir kann jemand helfen. Ich habe einen Kunden im Chip Fertigungsumfeld.

Wir haben ein Problem mit YIELDs und einem dynamischen Output basierend auf den LOS Größen der Maschinen.
Er möchte jedoch keine SKU pflegen weil er der Meinung ist, dass "Planning" (Lot By lot oder fixed Reorder Point) erstmal nichts mit Artikeln zu tun hat sondern durch seine Maschinen /Arbeitspläne gesteuert werden müssen.
Im Endeffekt wünscht sich der Kunde eine dynamische Planung basierend auf WELCHE Maschine kann den Job erledigen. Hinzu kommt, dass auf dem Arbeitsplan eine LOSGröße steht, dem Kunde wäre es recht wenn diese Einfluss auf seine Planung hätte.

Hat jemand ein paar Ideen?

Ich könnte mir was vorstellen was gehen könnte aber vielleicht gibt es noch mehr best practise Ideen?
Vielleicht kennt jemand eine Firma die ebenfalls solche Probleme hat bzw. die Lösungen auf die Fragen gefunden haben.

Hier mal ein Auszug des PROBLEMS.

we are a Chip producing Company and produce Computer Chips with different Lot Sizes. We have a really strong based industrial Focus and want to produce 10K Chips in Month.
We have a certain Problem which we can’t solve at the moment. My suggestions were not enough to fullify our process.
We have 1 Transceiver (TRX) as an assembled main product. We create a MRP (material and resource planning) for 500 PCS.
Our Routing defines that we have 10 % scrap and we can have a LOT Size of 50 or 100 Based on which machine it will be assigned. Below this first assembly there is a 1st Sub Assembly with the component “Chips” (like in a BOM). For this we must create LOTS with the size of 50. For the Next Sub Assembly we need a LotSize of 200 for a further SUB Components “Engine”. In the assembly of the “Engine” there are the components “EPIC” with lotsize 746 and “LMP” with lotsize “400”.
We must produce the whole lot size even if we do not need so much. Overproduction of a component is placed in stock. But the Qty of required components for the next production step must be completely available, scrap excludet.
In a BOM:
Component Lot Size Scrap (in 1 lot) output
2 Chips 50 10% (5pce) 45
3 Engine 200 5% (10pce) 190
4 LMP 746 10% (75pce) 671
4 EPIC 400 10% (40pce) 360

For first Production Line "TRX" planning output is 45pcs. We put 50pcs in the Machine and get out 45 (10% Scrap). So Material Consumption will be 50 and output Qty of the Production Order should be 45.
Now we want that the System provides us production order suggestions (MRP) for 500pce TRX with a lot size in prod order of 50pce Chips and Outputs of 45pce TRX.
45 * 12 productions = consumption 600 Chips; output 540pce TRX; 40pce in stock; 60pce scrap
This is the basic of the calculation for the whole BOM. After this all lower levels of the production have to be calculated in the same way. So, 600 Engines are needed to produce 500 Chips:
190 * 4 productions = consumption 800 engines; output 760 Chips; 160 in stock; 40 scrap
I think the principle is clear…

Actual I created Planning Parameters for all Items. All items get “Reordering Policy” "LOT for LOT". "Fixed reorder Qty" could work too. For Chips we have a Lot Size of 50, a Minimum Order Qty from 45 and Maximum 45. This make for all virtual LOTS incl. Yield. Engine get 190 (LOT 200, 5% scrap), LMP 380 (LOT 400, Scrap 5%) etc.
With this trick we say the system, you can Produce only in this SIZE. The Setting works for the production BUT that is not Enough for my Colleagues. Because it maybe could DENIED us later Options for Replenishment. Another problem is that Minimum and Maximum Order Qty can be flexible because the yield is increased if production output Qty were better as expected. So, the item parameters would have to be adjusted.

We have some Questions:
1. Are we able to create LOTs for Machines, what can the machine carry incl. Yield, that impacts the material Planning?
2. Can we config the system in this way, that the OUTPUT from "Sub A" is the Input for "SUB B"
e.g. Output of “engine” production -500 chips- is the input in the next production order

3. Is there any other way without REPLENISHMENT Parameters for Items/Variant/Locations to define a FIXED LOT Size which have an impact on the quantity while planning production orders?
Why this? One item can be produced on different machines with different lot sizes. So, we must be flexible with the lot size.
And we don´t want to minimize our future functions for reordering these components. Different Locations make no sense, variant will be used in another way! Increasing the YIELD (SCRAP) can´t be an option on item or Variant.

At the moment my solution looks like the following. But I need a feedback if this could work:
1. TRX get “LOT for Lot” without any Order Modifier
2. TRX Prod get 500 pcs from MRP Order. Than we must implement a logic, which get the LOT Size from Routing (50) calculate Yield = 45 and SPLIT the Prod Line for 500pce in 45 * 12 prod order Lines
3. Engine production in the same Way, System create an order based on Consumption 50 * 12 = 600 GOODS, we assign the lot 200 and get 4 * 190 = 760 GOODS Finished, rest go to Stock
4. ALL Processes must reserve the QTY from the “upper” production level to the “lower” prod level (Should be for Time calculation I think)
5. Reschedule from the lowest production level up to the first.
Could this work? Is it possible in standard or did we need any adjustments?