Sunday, March 16, 2014

Bill of Material Lifecycle

In last blog, I discuss on BOM concept. There I mention various Bill of Material aspects in various stage of product and their dependency. It is interesting to discuss on BOM lifecycle and its evolution from conceptual stage to full fledge manufactured product to maintenance. In this blog I will explain through life cycle of BOM across the product life cycle done as in house development. The BOM lifecycle can varies based on overall process of company for example some company might only manufacture as order hence they As Build design BOM and they directly CREATE Manufacturing BOM from it.

Concept BOM

As the product is visualize based on input from various source like client, sales, technology advancement etc, the Bill of Material creation started.  The concept BOM can be created either from scratch or derived from existing BOM. This BOM can be generated from CAD if the product is more engineering rich product or non CAD if it more features bases products where CAD might be subset of overall product. This BOM are used for proof of concept and goes through various iteration for design feasibility, cost consideration, compliances etc. Once concept phase is completed and decided on basic design and feature of Products, it moves product design.

Design BOM

Design BOM usually driven from concept phase. Design BOM can be derived from concept BOM or can be created completely new based on maturity of concept BOM. BOM are either created Top Down or bottom up. Top down BOM as name suggested design by defined from top like modules or assembly level and defined detail part in advance stage of product development, where as bottom up come to picture where design is done from parts or component level. Usually functional driven product development is done top down where systems or subsystems are defined first and then boiled down to detail design of Bill of Material. Complex product is usually designed through Top down design like Space Craft, heavy automatic machine etc. Teamcenter has Modular BOM functionality to support Top down BOM. Design BOM is usually CAD driven with physical and geometric aspect is modeled in CAD software and related data manages in PLM which is usually integrated with CAD package. Design BOM evaluate from basic CAD design to sophisticated CAE for Analysis BOM. Typically CAE BOM is derived for detail design BOM and is cross link through BOM management software. Once Design BOM is release for multiple iterative process and analysis, it handed over to manufacturing department for manufacturing the product from Design BOM. Manufacturing again realign the BOM from manufacturing aspect and create MBOM.


Manufacturing BOM:

Manufacturing engineer create MBOM (Manufacturing BOM) from Design BOM. The basic difference between Design BOM and MBOM is that design engineer look the Product in development from perspective of end product with detail of parts and components where manufacturing engineer look it from perspective of manufacturability of the product. Hence manufacturing view of BOM component and there sequence might be different from that of designer. For example designer might look two components for the given assembly as direct child of assembly, where as manufacturing might look same two components as parent child of each other from assembly sequence perspective. Similarly same component in the design BOM might be shown as two parts in manufacturing BOM. For example T plate might be single part for the designer but for manufacture engineer it two parts with welding operation. Apart from component reorientation manufacture engineer also add information in MBOM related to tools, fixture etc to encapsulate complete information for manufacturing the product. MBOM can be either created in PLM system or ERP like SAP PP. MBOM is usually required CAD assistance for aligning the design part and adding resource like tools and fixtures. Also most of manufacturing are done through NC (Numeric Control) machine, hence NC programming is also create from the given geometry information of part in MBOM. This NC programming is feed in to machine through series of operation information also called routing or Bill of Process. Routing or BOP (Bill of Process) is a detail operation sequence to produce or assemble a given Part or Product. The BOP is created in context of Manufacturing BOM and BOM component can be related to one or more operation in BOP. Rout

ing or BOP is usually done in ERP like SAP, but now PLM vendor also provide very good functionality for Routing which tightly integrate by MBOM and CAD\CAM and NC. Teamcenter provide Part Planer which provide tight integration with MBOM, BOP and NX CAM. This type integration provides better leveraging of information in one place. The below diagram depicit the complete lifecycle of BOM and relation between MBOM and Bill of Process.

Service BOM:

Once Part or Product is manufactured, it required to be service and maintained throughout Product life cycle. For consumer items like Mobile, TV etc it means managing serviceable parts and for complex product for example heavy machinery it means not only managing serviceable parts inventory, but also managing periodic maintenance and overhaul of the system. Hence OEM (Original Equipment Manufacturer) also publish Service Bill of Material along with Product specification, so that proper planning for spare part inventory, maintenance and overhaul can be done by Product owner. Service BOM usually will be derived from Design BOM as it’s more closely related to part information and detail then the manufacturing. But it also will derive from MBOM from maintenance and overhaul perspective. For example assembly sequence.  Service BOM also contains more specific information relevant to serviceability perspective like information of oil on bearing etc.

That’s all on BOM Lifecycle. Hope this might help you to understand overall Bill of Material concept and its use in various stage of Product.

See Also :
Bill of Maaterial Concept

Sunday, January 19, 2014

Bill of Material Concept

BOM management is most important functionality of PLM system. BOM is most critical component in a product based industry and managing it is still most challenging aspect in PLM system. The complexity increases as BOM lifecycle doesn’t reside just in one system or domain but in multiple Enterprise systems. Also Bill of Material for a given Product or Part means different to different section of people in the company based on their perspective and functionality for the given BOM. In this blog, I will discuss BOM basic, variation and challenge for managing it in any enterprise.

Concept of Bill of Material: BOM is defined as “A comprehensive list of raw materials, components and assemblies required to build or manufacture a product”. Hence it is a detail recipe of product which help to define, build and maintain a product. Since product goes through various lifecycle and interacts with various discipline or domain from Design to Manufacturing to Service to Finance, Bill of material also goes through similar lifecycle and various discipline or domain. Hence for a given product there resides many BOM based on the lifecycle and discipline which required using it. For example Design Engineer mainly deals with Functional aspect of product where as Manufacture Engineer deals with manufacturability aspect of product. Hence the way the Design Engineer look same BOM is different from manufacture engineer. Same is true for Service Engineer, Procurement etc. Each one has his own way of looking of BOM. There is numerous ways for defining the BOM for same product. In technical terms, BOM can mainly classified as follow

a)      Design BOM (EBOM): This deal with functional aspect of product. This is mainly first steps of BOM creation for a product. The design BOM usually originates from CAD model or Functional architecture breakdown. Manufacturing BOM usually derived from Design BOM.\

b)      Manufacturing BOM (MBOM): This BOM deals with manufacturing aspect of Product. Hence it can have detail related to manufacture information along with part detail of product. For example Tools or Fixture can be part of Manufacturing BOM (or it can be reference in the Part). Also some single design part can be consider combination of component ( Ex : Welding two plates ).

c)      Material BOM: This BOM mainly managed in ERP system for inventory and process planning. They deal with actual physical aspect of parts. Design or Manufacturing BOM can have component which might not be real or perishables item. For example MBOM can have component for intermediate manufacturing operation which doesn’t exist as storage or tangible part.

d)      Service BOM: This BOM deals with Serviceability of Product. This BOM has only that information which defines the service aspect of Product. Hence it deals only with list of part which is serviceable. Therefore this BOM doesn’t have detail for subassembly which constitute as a single part from service perspective.

Apart from above BOM type there are some other BOM type like Order BOM, Procurement BOM etc which are derivatives of above BOMs with some variation. Also BOM can also be distinguishing based on configurability of BOM.

Configurable BOM: From single BOM, based on certain rules or condition you can derive various resultants BOM. For example for a given model of a car, you can multiple versions. The Configurable BOM is used to dynamically create "end-items" that a company sells. The rule as basically variant and condition are option for those variant. For example based on engine type, power train can be selected in a given BOM. Configurable BOM provide a means to company to manage single BOM for multiple products variant. This saves considerable time and cost to company. All major PLM tools provide configurable BOM management modules.

Master BOM: Looking at so many BOMs variant for a given product, it is always a night mare for the company to manage all BOM and synchronize all when there is any change in either upstream (Design) or downstream (Service). To overcome this challenge, the concept of Master BOM has come.  Master Bill of Material can be defined as single source of BOM having all aspect of information for various configuration and discipline. Hence Master BOM by definition is single source of truth for all BOM. Industry is still struggling to find the exact solution in term of defining and managing Master BOM. Also it become more complex due to the facts that different BOM types are managed in different systems. PLM vendors including Siemens PLM has come various solution and tools, but still required to show the success and maturity of managing Master BOM as a single source of truth across various BOM lifecycle and discipline.
That’s all from my side on Bill of material. PLM vendors provide various powerful BOM tools for Managing, Collaboration and Visualization. I will discuss some of those in my coming blogs.

See Also :
Bill of Material Lifecycle