Detailed analysis of SAP BOM

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• I. Product Structure-importance of BOM
• II. Key Points of establishing the product structure
• 3. System File design of product structure

I. Product Structure-importance of BOM

BOM (Bill of Material) is called a bill of materials, also called a product structure table or a material table.

Separate raw materials, spare parts, and assembly parts of the product, and separate individual materials according to the materialsCodeThe product name, specification, unit usage, and loss are recorded in the order of the manufacturing process and arranged as a list. This is the material list, that is, the BOM.

Bom is:

• The foundation of MRP.
• Calculation basis of manufacturing orders.
• It is essentially an engineering document, not only the product specifications, but also the basis of the manufacturing process.
• Used to calculate the basis of product costs.

The importance of BOM and Its Impact scope are large, so its content must be correct and timely at any time.

II. Key Points of establishing the product structure

• The BOM must display the manufacturing level.
• Bom must be clear.

Bom must display the manufacturing level

The ideal bom should not only display the product structure, but also indicate the stage of the product in the manufacturing process. That is, BOM must define the product from the manufacturing level. Each layer represents the completion of a specific step in the process, and each inventory item contains the warehouse receiving and action at the top and bottom layers of BOM.

Bom must avoid ambiguity

The unit of a job is the key. A batch of components are independently assembled and are a complete unit that is sent to inventory or the next workstation. Therefore, it is necessary to define a part number. If no item number is defined, MRP cannot generate necessary orders for the component.

3. System File design of product structure

Although there are many layers in the product structure, in the system, we only need to maintain the relationship between the parent and subitem in a single layer, and then connect them, you can get the product structure of multi-class relationships.

The above is a four-level Bom. In the ERP system BOM data table, you only need to establish a parent-child relationship to obtain the complete Material Table of X products. As you can see, the Child item of the previous structure becomes the parent item in the next structure.

BOM can be divided into multiple types.

• Production BOM
• Sales BOM
• BOM for packaging materials;
• BOM for customs.

1. Bom for Production

In addition to describing the relationship between parent and child items, there are also the following essential fields, which are described as follows:

(1) serial number

Due to different processes, different effective periods, or different plug-in locations, there may be multiple sub-items under each parent item. In this case, the Unit usage cannot be used, and the parent and child items may not be unique. Therefore, the same parent item is described using the unique sequence number. Due to the nature of the item or the priority of the item sending, the sub-item must be arranged in a certain order, which is also achieved through the serial number. The BOM is displayed in sequence.

(2) unit usage

The number of sub-items required for each inventory unit parent item. The inventory unit of the item is defined in the material code table.

(3) Base

Indicates the number of parent items. For example, each carton (a material code) can store 100 watches (X). The BOM is as follows:

Parent item: x Sn 1 subitem: a unit usage: 1 base: 100

(4) Loss Rate

For some materials, such as machine and equipment, or assembly, normal UNIT usage cannot meet the production needs, and the loss percentage should be defined.

(5) fixed loss

According to the loss rate, the consumption of different orders is different, the amount of consumption of less orders is also small, the amount of consumption of a large order is also large, however, sometimes even a small number of orders require a certain amount of loss, which can be defined by a fixed amount of loss. That is: no matter how many orders, there must be at least so much loss.

(6) effective date and expiration date

The effective date and expiration date must be specified because of engineering changes or product structures in different periods. If it remains valid, do not specify the expiration date, or specify a large date, or make the expiration date = "1900/1/1"

 

 

(7) Material sending process number

Each parent item defines a process route in the material code company data table. Each process route must at least define one or more processes in the process route data table, different BOM sub-item may be sent to the same process or different processes. This shows the process to which the sub-item should be issued. When creating a manufacturing order to generate material details, if no serial number is specified in the BOM, the first process in the process route table is used as the material sending process.

(8) Status

BOM has three states: To be confirmed, OK, to be confirmed, to be confirmed when new BOM Sub-item is canceled, only OK sub-item can be used. The subitem to be confirmed or OK can be canceled.

(9) customer supply marks

Indicates the item provided by the customer. This item cost is not taken into account during cost calculation.

(10) Manufacturer

Some of the materials under the parent item must use a certain brand. In this case, specify the brand manufacturer and refer to when purchasing orders and sending materials. Even if the manufacturer is different, the new material code can be defined to reduce the material management and reduce the material substitution relationship.

(11) Plug-in location

Specify the position where the child item is placed on the parent item. For example, if a capacitor is placed on the P11 position on the circuit board, the plug-in position is P11.

(12) Start batch number

Sometimes, a sub-item in the BOM is used only by the specified batch number, but is invalid in other batch numbers. You can specify the start batch number and end batch number.

Note that batch number control is required only in the following cases:

(1. When the storage period of products or materials is limited;

(2) do not use batch number control when there are special requirements for the product or the printing and packaging are different without adding additional models.

(13) end batch number

Refer to the start batch number above.

(14) Remarks

It is only used for annotation description.

2. Sales BOM

It is also called the sample Bom, Which is a part list. It only describes the parts list of a finished product (model) and the standard unit usage. It has only one layer of structure and does not contain manufacturing information, most of the sub-items are the lowest-layer parts, which may be standard accessories or processed semi-finished products. However, accessories or semi-finished products are not expanded in the BOM of R & D, so they are treated as parts. Refer to the sales BOM material standard cost for Product Quotation.

3. Packaging BOM

Some companies need to pack the finished products according to the customer's requirements. Therefore, even for the same model, different orders and batch numbers are different due to different customers, different packaging materials and different packaging processes are required.

If you put this part in the BOM for production, you need to generate a lot of finished material code. Therefore, separating this part, using the same finished material code, with different customers, orders, batch number signs, can reduce a lot of finished material code.

This is not necessary. If the package does not change much, or there are not many models, you can add the packaging materials to the BOM for production. The structure of the packaging material Bom is roughly the same as that of the production Bom. the following fields are added:

(1) Customer Code

If this parameter is specified, the subitem can only be used by the specified customer. If this parameter is not specified, all customers can use this subitem.

(2) Order code

If specified, the subitem can only be used in the specified order code. If not specified, all orders can use this subitem.

(3) Batch Number

If a batch number is specified, the subitem can only be used for the specified batch number. If no batch number is specified, this subitem can be used.