First, some terminology:

(Always useful, even if some terms are not used in the post)

Part : any component, sub-assembly, assembly, product that is referenced during the product or manufacturing design

Manufactured Part: This is the actual physical piece that has been fabricated according to the specifications provided in the design, in a Manufacturing Process. It involves the utilization of materials, machinery, and labor to transform a design into a tangible item that can be assembled or integrated into a larger system or product. Once produced, the manufactured part is stored in a stock, and extracted on demand to be consumed in a new Manufacturing Process . These parts are usually designed to meet specific requirements, dimensions, materials, or tolerances that are unique to the company’s products.

Design Part: Conversely, a design part is a conceptual or virtual representation of a component. It exists in the form of drawings, CAD models, or other design documents, containing all the specifications, dimensions, materials, and other information required to manufacture the part. The design part serves as the blueprint for creating the manufactured part.

Configured part: fully defined part, with no ambiguity in term of definition, unlike generic parts, which can for example carry options/variants.

Material (or Raw Material) : Raw materials are the unprocessed natural substances or basic elements used as the starting point in manufacturing and production.

Work-In-Progress (WIP): refers to the goods that are in various stages of the production process but have not yet been completed. These items have already incurred some labor, material, and overhead costs but are not yet finished products.
WIP is not managed in stock, thus, in most of the case, it does not have any part number. It is referenced as the result of a manufacturing operation.

Semi-Finished Parts : A semi-finished part is a component that has undergone some, but not all, of its manufacturing processes and is intermediate between raw materials and the final product. It may require further machining, shaping, or assembly to become a finished part suitable for use in a final product. A semi finished part passes through a stock, so, he has to have a part number.

Part Number : a part number, for a configured part, is an Id that defines a class of equivalence. Two objects that have the same part number are fully interchangeable. A part number is absolutely mandatory for each purchased or manufactured part that passes through a stock.

You cannot discuss about MBOM without knowing what Manufacturing Process Plan (MPP) is :

A Manufacturing Process Plan (MPP) is a detailed document or roadmap that outlines the steps, sequences, methods, tools, equipment, and standards required to transform raw materials and compoents into new manufatured parts.

Here’s what the Manufacturing Process Plan typically includes:

  1. Sequence of Operations: The MPP lays out the precise sequence of steps that must be followed in the production process, from the preparation and treatment of raw materials to assembly, finishing, and inspection.
  2. Workstations : workstations and machines on which manufacturing operations are performed
  3. Tools and Equipment: The plan specifies the tools, machinery, and equipment necessary for each stage of production, including their setup and calibration.
  4. Materials and Components: The MPP lists the raw materials, semi-finished parts, and other components required.
  5. Quality Standards and Inspection: Quality control measures, acceptance criteria, and inspection techniques are outlined to ensure that the finished product meets the required standards and specifications.
  6. Labor and Skills Requirements: The plan may describe the labor requirements, including the necessary skills, qualifications, and training needed for different stages of the process.
  7. Time and Cost Estimates: Many MPPs also include estimates of the time and cost associated with each step, aiding in scheduling, budgeting, and overall project management.
  8. Safety and Environmental Compliance: The MPP may also contain information regarding safety protocols, waste management, and compliance with environmental regulations.

Product Design versus Manufacturing Process Design

In the world of modern manufacturing, the development of a product is no longer an isolated endeavor. The conception of a product and its manufacturing process is a parallel undertaking, intricately woven together to ensure efficiency, cost-effectiveness, and innovation. Here’s a closer look at how this parallel design process unfolds:

1. Reuse of Existing Parts or Subassemblies

The initial stages of product design often involve an assessment of existing parts or subassemblies that might be reused or adapted. This not only saves time and resources but also leverages proven components to enhance reliability. Reutilizing existing parts requires a clear understanding of inventory, previous designs, and how these components can integrate with new products.

2. Selection of Component and Subassembly Sourcing Methods

Choosing the right sourcing methods for components and subassemblies is a simultaneous consideration with product design. This involves critical decisions like:

  • Purchasing: Sourcing ready-made components that meet the required specifications.
  • Subcontracting: Collaborating with specialized manufacturers to produce certain parts or assemblies.
  • Internal Manufacturing: Producing the components in-house, leveraging existing capabilities, and controlling quality.

This choice is closely tied to factors like cost, quality, lead time, and strategic alignment with the overall product objectives.

3. Defining the Manufacturing Process with Impact on Part Design

The manufacturing process’s conception is not an afterthought but an integral part of the overall product design. The process selected can significantly impact the design of the parts, influencing factors such as:

  • Material Selection: Choice of materials that align with manufacturing capabilities and product requirements.
  • Tolerance Levels: Defining the acceptable variations in dimensions that can be achieved within the chosen manufacturing methods.
  • Cost Constraints: Aligning the part design with cost-effective manufacturing techniques without compromising quality.
  • Sustainability Considerations: Incorporating sustainable practices in both design and manufacturing.

By considering the manufacturing process early in the design phase, it is possible to create products that are not only innovative but also manufacturable, cost-effective, and aligned with market needs.

Conclusion about MPP: A Symbiotic Relationship

The parallelism between product design and the conception of its manufacturing process reflects a symbiotic relationship where each aspect informs and shapes the other. This synergy fosters innovation, reduces time-to-market, and ensures that the final product is not only a realization of creative vision but also a practical and marketable commodity.

In essence, modern manufacturing demands a holistic approach, where design is not confined to the drawing board but extends into the very heart of production, encompassing aspects such as part reuse, sourcing strategies, and process considerations that resonate with the product’s purpose, market positioning, and value proposition.

In such a case, MBOM is not « strictly-speaking » created from an EBOM. MPP is designed in parallel of the EBOM, with strong accountability check to verify that the two structures are aligned (i.e. all the design components have an equivalence in the MPP structure). Then, MBOM is a filtering of the MPP

Understanding MBOM in PLM: A Connection Between Design and Production

The Manufacturing Bill of Materials (MBOM) is an indispensable element within Product Lifecycle Management (PLM), serving as a bridge between product design and actual manufacturing processes. Its role in defining the flow of materials and components used in production is crucial. Here’s an in-depth look at the role of MBOM within PLM:

1. MBOM as a Filtered View of Manufacturing Process Plan (MPP)

The definition of MBOM is quite simple: for a product, sub-assembly or single part, it involves filtering the process plan, detailing the components and raw materials taken from stocks and consumed in the manufacturing process.
Thus, intrinsically, the MBOM is second-level information relating to the process plan. It translates procedural guidelines into concrete requirements for materials and components.

Thus, the answer to the question « What does my MBOM look like for a given product? », comes down to the following questions

  • How do I manufacture my product?
  • Which raw materials and components do I have to source?
  • Which intermediate components pass through inventory/stock during the overall manufacturing process?

Of course, often, the MBOM structure is quite close to the EBOM structure.
But do not forget that they can be quite different. Think about the products delivered in kits.

2. Integration between PLM and ERP Systems

As soon as the manufacturing process is complex enough, it is worth creating the the process plan and MBOM within the PLM system, using all the Product Data Management and Manufacturing Process Simulation capabilities
Once created in the PLM, the MBOM is leveraged in the Enterprise Resource Planning (ERP) system, where it guides procurement, production scheduling, and inventory management.

In Summary: MBOM Describes Inventory Flows

The MBOM serves as a dynamic roadmap that describes the incoming and outgoing flows of stocks, components, and materials within the production process. Of course, it must be aligned with the EBOM (ie all the components of the eBOM must be ‘consumed’ in the MBOM) , taking into account several main differences. Just a few examples :

  • Components of purchased or subcontracted subassemblies do not appear in the MBOM.
  • Raw materials appear in the MBOM of manufactured parts
  • Components that are produced during the Manufacturing Process as WIP (i.e. that do not pass through a stock during the manufacturing process) do not appear in the MBOM, but their raw marerials do !
  • Some semi-finished parts can appear in the MBOM (for example, if some manufacturing operations are subcontracted)
  • You can have some specific manufacturing objets, like kits
  • …

To conclude

Often, a product is designed, and defined, in the way it will be manufactured. That’s why EBOM and MBOM are often close. But that shouldn’t make us forget that EBOMs and MBOMs serve two different purposes. EBOM defines the products, MBOM the supplys needed to build the product, and the flows between stocks and production lines.

And, for complex products this not solve one of the main questions of PLM :

  • How do we guarantee the alignment between Design and Manufacturing during the whole lifecycle of the product ?

This alignment, which is the foundation of digital thread relies, on a strong change management process, but also on technical functionnalities. To be developped in further posts !