An essential step in manufacturing is completing a bill of materials, or BOM. Also referred to as an assembly component list, product structure or product recipe, a BOM is fundamental to the effectiveness of multiple manufacturing and supply chain processes, including production, materials requirement planning, inventory planning, scheduling and product costing. Show
What Is a Bill of Materials (BOM)?A BOM is a structured, comprehensive list of the materials, components and parts required to manufacture or repair a product, as well as the quantities in which the materials are needed and their names, descriptions and costs. A BOM also includes instructions for procuring and using these materials. Because of the breadth and depth of the data it captures, a BOM can act as a central record of the materials, components and processes used to build a product. Key Takeaways
Bill of Materials ExplainedA BOM is essentially a blueprint for manufacturing a product. It encompasses the materials, components and steps required to create the item. Most BOMs are structured in a hierarchy. At the top is the completed product, next are subassemblies and below those are the components and materials that go into making the product. This includes details like part names, numbers, descriptions and the quantities needed. While the concept of a BOM is straightforward, creating and managing bills of materials can become complicated, especially for products composed of hundreds or thousands of parts. For instance, if it becomes necessary to change one component because a supplier can’t meet its delivery deadlines, this change needs to be replicated throughout the BOM wherever that component is used. Some basic parts, like adhesives, may be used in multiple areas. Why Use a BOM?BOMs facilitate efficient and accurate manufacturing. By identifying and pricing all the materials and components needed to make a product — before production begins — an organization can determine whether it has everything it needs to move forward with minimal risk of delays. This reduces the likelihood of both shortages and overages of materials or components. By helping ensure the right parts and materials are available at the right time and in the right quantities, BOMs help manufacturers remain within budget and on schedule. Companies that work with contract manufacturers and provide the manufacturer with a BOM can be more confident the final product will meet their specifications. Conversely, proceeding without a BOM increases the likelihood of costly and time-consuming mistakes. These include shortages or overages in materials, production downtime while the materials are assembled and additional expediting charges to make up for earlier delays. Who Prepares a Bill of Materials? Who Uses a Bill of Materials?Given the range of information within a bill of materials, creating one often requires input from a company’s cross-section of functions. This can include design, engineering, purchasing, materials management and manufacturing. Similarly, different areas within a company can be primary users of different types of BOMs. For instance, engineering and/or design typically uses an engineering BOM. Manufacturing generally uses manufacturing BOMs. 10 Key Elements of a Bill of Materials (BOM)What is included in a bill of materials? Most BOMs include the following elements: BOM level; the part number, name, description and quantity; cost; and the unit of measure. While the bill of materials includes components and parts, it doesn’t include labor.
Bill of Materials (BOM) DisplaysBills of materials generally are presented in one of two ways: Explosion DisplayIn an explosion display, the BOM starts with the highest level of the product — say, computer motherboard — at the top. It then breaks the product down into components and parts that become increasingly more granular. The graphic shows the Costed Bill of Materials (BOM) Inquiry displayImplosion DisplayAn implosion display is the inverse of an explosion display. It starts with individual parts and links them to form the major product or assembly. The graphic shows the Component Where Used Inquiry displayAdvantages & Value of a BOMWhy is a bill of materials important? By providing a single record of the materials, components and assemblies that go into the product, a bill of materials ensures these items are in-house when needed and at the quantities required during production. This minimizes inventory inaccuracies and production delays, both of which cost time and money. Bills of materials also ensure uniformity. When each production run follows the same BOM, the products themselves remain consistent. This helps ensure they meet customer expectations and is critical when products need to meet safety or other standards. The information contained within BOMs also is key when it becomes necessary to track product failures. With this document, it’s possible to identify the parts, materials and components used and zero in on potential sources of failures. Manually preparing and managing BOMs can quickly become unwieldy and error prone. Software, such as a supply chain and inventory management solution, can help automate the development process. The Two BOM StructuresBOMs may be structured in one of the following two ways:
Free Bill of Materials (BOM) TemplateDownload our free bill of materials template to plan purchases of materials, estimate costs, plan for and control inventory and minimize production delays and waste. Get the free BOM template Types of Bills of MaterialsBoth single- and multi-level BOMs may be created for use at various stages of the product development lifecycle. The primary types include engineering, sales and manufacturing BOMs. Each focuses on different information. Engineering Bill of Materials (EBOM)An engineering BOM is developed while a product is being designed and defines a finished product’s original design. It includes the items, parts, components and subassemblies as designated by engineering. It generally consists of a technical drawing of the product. Engineering BOMs, as their name indicates, typically are developed by engineers. They often use computer-aided design (CAD) software or similar systems to create the BOM. Sales Bill of Materials (SBOM)A sales BOM lists the products and components required to develop a product as ordered by the customer. It’s developed from the sales order and includes both the finished product and components, as they appear in the sales record. Manufacturing Bill of Materials (MBOM)A manufacturing BOM is used during production. It identifies the parts and assemblies needed to produce a shippable product, including packaging, and accounts for waste and items consumed in the production process. An MBOM identifies the groups of parts needed at each stage of the production process and provides information on the processing required by various parts before assembly. This helps determine when materials must be purchased and when various manufacturing processes need to begin to meet scheduled delivery dates. For a new product, an MBOM may last for a set period, such as several weeks. Then, if it becomes clear the product requires changes, the MBOM can be updated or a new one may be generated. Information in the MBOM typically is shared with several systems, including the enterprise resource planning (ERP) system and material requirement planning (MRP) systems. Configurable Bill of MaterialsThis BOM is used for finished products that are configured and designed to meet specifications requested by a customer. It identifies the materials and components, including any labeling or packaging requirements, needed to manufacture the product to the customer’s requirements. Production Bill of MaterialsA production BOM acts as the foundation for a production order and includes the components and assemblies that make up a product. As production proceeds, the components are converted to finished products. Assembly Bill of MaterialsLike a sales BOM, an assembly BOM lists the parent item as a sales product rather than an inventory item. An assembly BOM also lists sub-assemblies (or children). Template Bill of MaterialsTemplate BOMs offer flexibility, as they can be used for either production or sales BOMs. These also include parent and child components. How to Create BOMs in 7 StepsDepending upon the industry, designers or engineers as well as purchasing, scheduling, and planning workers will want to review them to ensure accuracy — an accurate BOM serves as a roadmap for finished goods and frees up resources to spend on the actual production process. Several steps are involved in creating an accurate, useful bill of materials, among them:
History of the Bill of MaterialsAccording to Form Labs, a digital fabrication company, World War I prompted advances in the discipline of materials management to help companies best use scarce materials to fill orders of goods needed for the war. Following this and before World War II, engineers used early versions of BOMs to specify components within technical drawings. In the 1960s, advances in production planning emerged, like Toyota’s Just-in-Time approach, as well as materials requirements planning, or MRP. Also, in the 1960s, enterprise resource planning (ERP) was applied to inventory management and control. Software engineers created programs to monitor inventory and reconcile balances. By the mid-1970s, more than 700 companies were using MRP; this swelled to 8,000 by the early 1980s. In addition, the concept of MRP expanded to include more processes, like accounting and human resources. Companies could use BOMs to plan for the materials outlined in the master production and purchasing schedule. This helped in managing inventory and reducing delays. Today, ERP also encompasses business intelligence and front-office functions like ecommerce. Companies of all sizes and across all industries use ERP solutions. Make the Most of BOMs With an ERP SystemManually preparing and managing BOMs can quickly become unwieldy and error-prone. Software, such as a supply chain and inventory management solution, can help automate the development process. ERP systems also can automate the tracking of changes to BOMs and identify discrepancies that can occur when multiple areas, such as engineering and manufacturing, generate BOMs for the same product. To help organizations manage inventory levels across their supply chains, look for an inventory management system that includes inventory control, tracking and optimization. An accurate, thorough and updated bill of materials improves decision-making and facilitates efficient production processes. It can help organizations more quickly move designs into production, which may help them capture customers. By cutting waste, BOMs help organizations save money. Because of the depth and breadth of information they provide, BOMs can boost supply chain resiliency. Conversely, neglecting to create a BOM or failing to update one can result in inaccurate product costs, products being made incorrectly, inventory overages or shortages and production delays, among other challenges. Which of the following best describes the purpose of an intermediate error event?which of the following best describes the purpose of an intermediate error event? Add a sequence flow to an end event after the discard errors activity. Consider the following BPMN diagram of a subprocess.
Which of the following business rules illustrates a proper implementation of internal control?Which of the following business rules illustrates a proper implementation of internal control? The employee that authorizes production can't be the same employee that issues raw materials.
Which of the following is the most likely order of a basic conversion activity model?Which of the following is the most likely order of a basic conversion activity model? Authorize Production→Issue Raw Materials→Perform Work→Complete Prodcution.
|