EVS Blog

Let’s first cover a few definitions. Discrete manufacturing is the assembly of widgets, process manufacturing is the blending of goop. Mixed mode manufacturing refers to products that require both blending and assembly. Can you think of a product that needs both blending and assembly?

(tick tock, tick tock, tick tock, DING) Okay, times up!

I’ll let you in on a little secret (shhhh, don’t tell anyone); most process manufacturing is actually mixed-mode. So the answer to the question is almost every single product made in the food and chemicals industry. Think about it, a bakery blends dough (process) then packages the bread (with a bag, label and 1/12 of a case) which is a simple assembly (or discrete). Any blended item that is packaged requires at least some type of discrete or BOM function.

So how do BOMS and Formulas differ? Let’s start with formulas:

A formula is essentially percentage-based (40% sugar, 40% flour, 20% eggs). Whether the percentages are expressed as percentages or more discrete numbers (30# sugar, 30# flour…)doesn’t really matter. A formula can be sized to meet a certain weight or volume; so our formula above, a 1,000# batch will require 400# of sugar. If you size the batch to 33.2# you would use 13.28# of sugar. Formulas should be able to use both weight and volume units of measure and be able to interpret to a total formula weight and total volume. If you put 40# of sugar and 40 gallons of flour in a blender, how many total pounds and total gallons would you have? Note, we’ll talk about density later. A formula is where your R&D lab spend their time doing product development.

A BOM assumes that you are going to assemble discrete parts; 1- desk top, 4-legs, 16-screws. You will always scale the BOM as a multiple of one. You would never scale a BOM to 150 pounds of desks or 37.2 desks. Many times discrete systems will tell you to simply make the BOM equal to one pound or one gallon then size based on a factor of one, again, this looks good in a demo but is a disaster in operation.

But, since process manufactured items require a BOM for packaging, we need a BOM. Can an ERP have both a percentage-based formula and a BOM? Yep, in a real process manufacturing ERP software you will. A finished good definition will have both a formula and a fill quantity as well as a packaging BOM.

To continue reading this series, see the next article: Process v Discrete Mfg #4: Batch vs. Work Order