How to Map Fomulas for Float Glass Process

Question

Hi All,
Can anybody suggest how to map formulas for float glass process.
As in float Glass process continuous production is going on single line, within that continuous ingredients are added in furnace and molten glass mass is coming out. this molten glass is now adjusted to particular thickness and then finally cut into specific sizes as per cusotmer requirment.
Final product is in various thickness, width and length.
Entire process is automated.
If anybody already implemented same scenario, please share knowledge.

Answer 1

Hi
The following is the mapping process and it is tricky process need to map carefully.
You can define this as a single formula.
Output: Packed - cut to size - Finished Good Item.
Input: All the Raw materials (Sand, Dolamite, Limestone, Soda Ash, Sodium Sulphate, Carbon, Iron Oxide)
Packaging materials + Labels + Boxes etc.
Define Routing:
Resource: Furnace, Any other importance resource like Equipment that controls thickness, cutter etc, Labor, Associated Overhead
Create recipe using the formula and routing.
Various factors that can affect the mapping:
1) Formula maintenance: You have to define formula for each output item.
2) Possibility of dynamic determination of output item: If it is possible to produce different combination of thickness/width (and hence different FG item) in the same batch, then this won't be the right mapping.
3) Process variations: Also formula mapping depends on how accurate is production process. If user wants to produce item X (say thickness 10mm) but due to quality issue produced item Y (say thickness 9mm) and such cases happens very often, this won't be right solution.
4) Inventory measurement: This will determine the break-points. If you cannot measure the quantity (or even estimate) then you cannot define it as an intermediate item.
I will explain how point 4 can lead to different way of formula mapping.
Say you have a furnace that needs to run continuously for better quality or throughput. Hence you will be continuously adding raw materials to furnace and produce different outputs. You can break the single formula into multiple formulas as -
Formula 1) Output: Molten mass of glass
Input: All the Raw materials (Sand, Dolamite, Limestone, Soda Ash, Sodium Sulphate, Carbon, Iron Oxide)
Formula 2) Output: Packed - cut to size - Finished Good Item.
Input: Molten mass of glass
To have formula in such fashion you should have a way to measure or estimate the weight of Molten mass of glass.
If you are estimating the weight, there should be historical data available to determine what should be realistic output quantity for given input quantity. How much will be process loss and loss due to unwanted by product such as slag etc.
Further you can break formula 2 as
Output: One large sheet of give thickness
Input: Molten mass of glass
Output: Packed - cut to size - Finished Good Item.
Input: The large sheet of give thickness.
This kind of different mapping is possible which normally depends on:
1) Complexity of process
2) How complex BOM structure user wants to have
3) Are there any benefits of maintaining such complex system - like accurate costing or accurate production monitoring or facilitating planning process.
4) Can user maintain the complex system? Are they ready to capture data at finer level. Is it possible to capture the data.
5) And most important thing is how to handle exceptions. If every thing goes smoothly as planned (less exceptions) then user can have and afford any level of complexity. But if there are many exceptions to the normal process you have to concentrate more on how to handle the exceptions.
6) Satisfy all users: Accounting, Planning, Production, Quality, Inventory handling. Formula/Recipe touches all these modules.
Regards
Raj
Sierra