A material workflow is an abstract process description for the production of a particular product type. In contrast to the workflow *, which describes "how and where" a product is to be manufactured, the material workflow describes "what" is being produced. However, no specific materials are specified, that are required for the production, as is the case with a BOM (Bill of Material).
For this reason, the material workflow is also the precursor of a BOM (quasi a template for BOMs of the same type).

* For the definition of the material workflow, classical workflows (program sequences) hereinafter referred to as "workflow".

Using an example, it is best to explain what a material workflow is:

Let's assume that you get the task of describing how a pie is made in principle without going into what work steps are needed. How would you proceed?

First you would think what concrete cakes you know (Sachertorte, strawberry pie...)- in software technology it would be technically a BOM (Bill of Materials). Then you would try to generalize the manufacturing process of these pies and omit the work steps (How & Where).

The result would be:

[A] Cake base
[B] Cake filling
[C] Unfinished cake (= [A] + [B])
[D] Glaze
[E] Finished cake (= [C] + [D])

As you can see now, there are some intermediate stages or abstract components [A-D] which are not yet a finished pie. Only with the last stage of production [E] would one get a finished cake if you cover the unfinished cake [C] with the glaze [D].

All these abstract production stages are referred to in Variobatch as intermediate products. Intermediate products are data-technically materials that have the indicator "intermediate product" in material management and which cannot be used as a stock in the warehouse, because they are

• firstly abstract generic terms and
• secondly unfinished or not saleable products that occur during the production process.

The plus sign describes that two intermediate products are mixed together or assembled. More specifically, "the first intermediate product goes into the second intermediate". This is called a intermediate product relationship.

Let's get back to our example and become concrete. That means we want to create a Sachertorte based on the "Cake production" material workflow.

The BOM would be in similar form:

[A] Flour
[B] Eggs
[C] Baking soda
[D] Apricot jam
[E] Butter
[F] Sugar
[G] Chocolate

However, the BOM does not say WHAT the individual components (materials in a BOM) are needed for.  Therefore, the material workflow and its intermediate products must be linked to the components of the BOM.

The result in our example would be:

[A] = [a] + [b] + [c]
[B] = [d] + [e] + [f]
[C] = [A] + [B]
[D] = [f] + [g]
[E] = [C] + [D]

The intermediate product [E] is the finished cake. If we wanted to produce and sell the cake in real, we could just start with the last intermediate [E]. Therefore, the last intermediate product in a production order always receives the specific material number of the product to be produced. In our example, it would be the material number of the Sachertorte and we could successfully book a pie more in the refrigerated warehouse as stock.
Conversely, if we produce a Sachertorte or a strawberry pie, something would go wrong in making the cake floor, we would have to

1. Dispose the intermediate product [A]
2. We could not assign a material number to the product, because the product is neither a Sachertorte nor a strawberry pie and therefore does not lead to a stock
3. We could only have a pie stock in a reject store with the reference that we wanted to make a Sachertorte.

A real confectioner would of course laugh at the fact that in a recipe one simply omits the work steps (HOW, WHERE, WHEN), because otherwise he could not do anything at All. This information is stuck in workflows. As a result, workflows must be linked to material workflows in the second step.

You can even assign multiple workflows to a material workflow (and vice Versa). This is understandable when you consider that it makes a big difference whether a Sachertorte is produced either at home or as a mass production in a factory. This is also comparable within a company when the same product types are produced at different locations or production lines. As a result, there must also be different workflows, because they are bound to different physical models. If a factory product is manufactured manually (e.g. small quantities), the process flow is completely different from that of the automated system which is next to it. Again, there must be two different workflows.

Now that one or more workflows have been linked to a material workflow, the process description is not quite complete. There is no information about which of the intermediates is produced at what time and at which machine type in the workflow. The linking of intermediate products from the material workflow with the workflow nodes in the workflow is the last step to complete the process Description.

In our pie example, This would mean the following:

There is a workflow that would have the following workflow nodes (work steps) (very simplified):

(10) Weigh in the container scale
(11) Stir in the container scale
(12) Empty the container scale on the baking pan
(13) Place baking pan in oven
(14) Baking at 200 °c

(20) Weigh in the container scale
(21) Stir in the container scale
(22) Place in refrigerator

(30) Place the saucepan on the table balance
(31) Weighing on the table balance
(32) Heating to 80 °C

(40) Cover

(50) Baste

 

Now we link the intermediate products to the workflow nodes (work steps):

[A] <---> (10)
[B] <---> (20)
[D] <---> (31)
[C] <---> (40)
[E] <---> (50)

Only now is a complete procedure description available because the work steps 10, 20, 31, 40 and 50 are material related and we now know which intermediates are manufactured at what time and where. By assigning a material workflow to a BOM and linking its components to the intermediate products, the workflow node now also knows which components it must process. (material-related work steps or workflow nodes are referred to as material receiving and material forwarding nodes. More in the section "routing rules")

This strict separation between the three data contexts

• Material workflows (WHAT),
• Workflows (HOW, WHEN, WHERE) and
• BOMs (WHICH Material)

provides some advantages:

1. The number of versioned BOMs is significantly reduced.
2. Physical independence of BOMs (location, plants, machines...).
3. The number of workflows is significantly reduced.
4. The re-usability and transparency is increased.
5. Flexibility and scalability are increased.

 

The following screenshot shows the link relationships between intermediate products and workflow Nodes:

 

On the left half of the screen you can see the material workflow with its intermediate products. On the right half of the screen the workflow with its workflow nodes. The red connecting lines show the linking of intermediate products to the workflow nodes.

 

Technical note

Linking to workflows is optional! If you do not control an automated system and only want to work in accounting, the link is omitted. An unlinked material workflow can also be assigned to a BOM later.

In order to create material workflows, you must perform the following work:

1. In material management, materials with the indicator "intermediate product" must be created.
2. Optional: In workflow management, appropriate workflows must be created.