# Define a Multi - Level Bill of Materials (BOM) in Production
**YouTube:** [How to Generate Raw Material Requisition Against Job Order in Production?](https://www.youtube.com/watch?v=-Jrrz_tP2PE)
## How to Define a Multi - Level Bill of Materials (BOM) in Production?
In this tutorial, we will walk you through the complete process of defining **multi-level Bills of Materials (BOM)** in Logic ERP. Multi-level BOMs are essential when products require multiple internal production stages and semi-finished items need their own independent production. Let’s begin.
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### **Accessing the Raw Material Specification Screen**
* Navigate to **Items + Process → Raw Material Specs (Grid Mode)**.
* Select the **Item** for which you want to define the BOM.
* Click **Refresh** to load the existing Bill of Materials for that item.
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### **Enabling Multi-Level BOM (Multi BOM)**
To create multi-stage production structures:
* Tick the **Multi BOM** checkbox.
* If the option is not visible, go to **Configuration** and enable **Multi BOM** settings.
* This feature is required when:
* The finished product requires **semi-finished components**
* Each semi-finished component has its own **independent production process**
**Example:**\
If producing **Item A** requires manufacturing **Item B** and **Item C**, each with separate production stages, a **multi-level BOM** becomes necessary.
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### **Defining Process-Wise BOM**
To add BOM details for a specific production stage:
#### **3.1 Select the Production Process**
* Choose the **Process Name**.
* The related **Process Group** appears automatically.
#### **3.2 Choose Relevant Raw Material**
* Select the **Body Part**.
* Then select the **Raw Material Item** required for that process.
#### **3.3 Size-Wise Material Consumption**
* In the **Sizes** column, define the **quantity of raw material required** for each size.
* This ensures accurate and size-based consumption planning.
#### **3.4 Costing Information**
* **Plan Cost Per Unit**: Estimated or standard raw material cost.
* **Actual Cost Per Unit** and **Actual Amount Used**:
* Recorded during production
* Helps track real-time consumption and variance analysis.
* After entering all details, click **Save**.
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### **Understanding the Multi-Level BOM Tree Structure**
* The **left panel** displays the complete multi-level BOM hierarchy in a **tree format**.
* It helps you:
* Visualize production stages
* Track semi-finished components
* Understand material dependencies clearly
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### **Adding Semi-Finished Components**
If your product includes semi-finished items:
* Define a separate BOM for each **semi-finished component**.
* Link these components to the **finished product’s master BOM**.
* **Mandatory:** Ensure **Multi BOM** is enabled for semi-finished items.
* Without this option, the system **will not generate separate job orders** for semi-finished items in future production stages.
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### **Useful Shortcut Keys**
To speed up BOM creation, use the shortcuts shown at the bottom of the screen:
* **F2** – Update quantity for the selected region
* **Delete** – Remove quantity from the selected region
* **F5** – Copy raw material details
* **F3** – Update quantity using an expression
* **F6** – Import raw material specifications from an external file
These shortcuts significantly enhance efficiency when managing large and complex BOMs.
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## **Conclusion**
By enabling Multi BOM and defining stage-wise raw materials, size-based consumption, and separate BOMs for semi-finished goods, you can build a precise and structured multi-level Bill of Materials. This ensures accurate production planning, cost control, and efficient job order generation within Logic ERP.
