Production Lot 
Production Lot
Definition
The production lot is a particular production unit of an assembly which is planned and manufactured with reference to a number.
The number of the production lot is a WBS element which the system produces whilst creating the number.
Use
By using the production lot number, you can already determine the planned and actual costs that are incurred when manufacturing a particular production quantity of an assembly, before receipt of the sales order.
With this number, you plan and produce the production lot of an assembly and calculate the planned and actual costs for the production of the assembly.
If the manufacturing process of an assembly changes, you create a new production lot number and carry out the planning, production and the planned and actual cost calculation with the new number. This enables you to determine the costs of different manufacturing processes separately and compare them to one another.
This is particularly important for branches of industry which, due to continual product improvements and cost reduction processes, have to plan and produce their finished products or semi-finished parts using different BOMs, routings or change status.
This procedure can be applied for both finished products and important semi-finished parts. Within a BOM structure, you can define a production lot number each for both the finished product and a semi-finished part.
Structure
Two types of production lots are available for planning.
With this type of production lot, the material stock for each production lot is managed separately in individual project stock. This is necessary if the assemblies of the different production lots vary from one another considerably and therefore are not allowed to be mixed with each other in the general plant stock.
This procedure is used for finished products. In this case, a production lot number must be entered in the sales order. The sales order can only use the individual project stock with the corresponding production lot number.
However, you can also use this procedure for important semi-finished parts, if you want to decide from which individual project stock (production lot) you would like to take the stock, before you install the part into the finished product.
With this type of production lots, stock is planned separately for each individual production lot during the planning and production phase. When the production of the production lot has been completed, the assemblies of the production lots are transferred from the individual project stock to the plant stock.
This procedure can only be used when the assemblies of the different production lots do not vary considerably from one another.
You can apply this procedure for finished products and semi-finished parts. Semi-finished parts can be installed in any of the finished products.
Integration
If the ATP check is carried out for a production lot with sales order stock, only the individual segment of the production lot is checked, that is, only the goods receipt and issue elements of the material are included in the availability check that are assigned to the account of the WBS element, in addition to the sales order stock of the production lot (of the WBS element).
If the ATP check is carried out for a production lot with transfer posting to the plant stock, all segments including the plant stock is checked, that is, all goods receipt and issue elements of the material are included in the ATP check. In order to achieve this, in the MRP data, in the material master, you enter the 1 indicator in the field Cross-project.