When eBOMs and mBOMs converge

Product lifecycle management (PLM) is a business strategy that helps companies share product data, apply common processes, and leverage corporate knowledge for the development of products across the extended enterprise. As such, PLM software has gained the stature of being “the next big thing” in manufacturing enterprise information systems, assuming the mantle that ERP (enterprise ...

By Frank O Smith for Control Engineering October 1, 2009


For more on PLM’s expanding influence on the plant floor, search www.controleng.com for the following articles:

PLM software advances announced by Dassault, Siemens, Autodesk, Oracle

PLM: 3D Process Simulation Delivers

Siemens PLM adopts S1000D to tackle sharing of technical information

Product data management systems ready for small, medium companies

Digital manufacturing: Autodesk Inventor shows component interactions

Product lifecycle management (PLM) is a business strategy that helps companies share product data, apply common processes, and leverage corporate knowledge for the development of products across the extended enterprise. As such, PLM software has gained the stature of being “the next big thing” in manufacturing enterprise information systems, assuming the mantle that ERP (enterprise resource planning) software carried in the 1990s.

PLM has attracted the interest of major software vendors eager to participate in its expanding functional footprints, and analysts who spin fetching scenarios for how PLM will transform manufacturing as we know it. The truth is, although few are fully there yet, significant steps are being made by system integrators and pioneering manufacturers. The focus—and progress—today seems to be where engineering and manufacturing meet: in the distinct but related bills-of-materials that each group creates.

Like ERP, PLM is not entirely new: It’s built upon the legacy of its numerous component parts, including computer-aided design (CAD), computer-aided manufacturing (CAM) and product data management (PDM). PLM as a tool for manufacturers gained sizeable momentum and credibility in 2007 with Siemens’ $3.5 billion acquisition of PLM software vendor UGS. “Design for manufacturability”—the banner for the evolving promise of tying design more integrally with manufacturing—became recast as “digital manufacturing.” The vision is that technology will virtualize every aspect of product design and manufacturing, from concept to customer.

“Siemens’ vision for connecting all the pieces is clearly where the industry needs to go,” says Joe Barkai, analyst and lifecycle strategies practice director for IDC Manufacturing Insights. Nick Ballard, senior consultant for Cambashi, a U.K.-based industry analyst firm that closely tracks PLM, concurs: “Siemens’ acquisition of UGS was a serious sign of intent in the marketplace.”

PLLM software can help engineers get things done – from concept to production – faster and cheaper. Source: Siemens PLM

PLM progress from many angles

Dassault Systemes is another major PLM vendor with an emphasis on 3D online environments dubbed “PLM 2.0.” Dassault has pushed aggressively to keep pace with Siemens to reach down into the automation layer, largely through partnerships with companies like Rockwell Automation, Mitsubishi, and others. Both Siemens and Dassault fly the digital manufacturing flag, promoting comprehensive simulation of the entire process flow, from design to production and including “virtual commissioning”—the programming and testing of PLCs, robots, and the like based on CAD parameters.

PTC, a smaller, but very capable PLM vendor, puts greater emphasis on “process definition” built around its manufacturing product management (MPM) module. Autodesk, the world’s largest CAD vendor, approaches the market differently, gaining entry under the moniker of “digital prototyping.” Not as comprehensive, but equally committed to the market, are large ERP vendors like SAP, Oracle, Infor and others who are driving toward PLM from their enterprise system roots.


Teamcenter Manufacturing software lets users validate the completeness of parts in an mBOM. New, changed or deleted parts are shown in a graphical way to easily identify the items which require an action of the manufacturing engineer. Source: Siemens PLM

The potential impact on the functions of control and manufacturing process engineers is implicit in the vision of digital manufacturing. But outside the aerospace, automotive and a few isolated instances in other industries, “PLM ambition is still ahead of reality, like it was with ERP,” says Tony Christian, principle consultant for Cambashi. Says Barkai of IDC: “I’m somewhat disappointed that the pace is not faster, pushing down toward the automation layer.” But as yet, “it’s been harder to clearly demonstrate and quantify the value.” Which is not to say that the value is non-existent, experts say. Comprehensive simulation of production processes and virtual commissioning of automation lines are still more vision than reality, but there are growing examples already in play.

Time is cheaper in the virtual world

Applied Manufacturing Technologies (AMT) is a manufacturing system engineering firm based in Orion, MI. “We provide engineering solutions to everybody in the production food chain. We do hands-on programming and commissioning of robots, control programs, line start up, commissioning support, and system documentation,” says Andy Jones, account manager for AMT. “With the economic challenges today, people want to get things done—from concept to production—faster and cheaper than anyone else.”

To help its customers, AMT uses a variety of tools it’s developed, as well as commercial PLM tools from various vendors, including Siemens. AMT is engaged currently with a large automotive OEM to do pioneering work in virtual commissioning of automation lines. That customer uses Siemens PLM Teamcenter, a central repository for all product and process data, as its engineering backbone.

“Working in the virtual world gives you the ability to evaluate product changes and how they impact production before they hit the plant,” says Jones. “From a control engineering perspective, it enables you to take PLC or HMI systems and program and debug them virtually, verifying all faults before moving to the floor.”

Commissioning a system on the floor is costly and time consuming, Jones says, and even if PLM software “doesn’t save you time, it changes where you spend it. Time is a lot cheaper in the virtual world, and there’s a lot less risk. When [a new machine] hits the floor, everything is in steel, and process changes are tremendously more expensive.”

AMT is piloting the virtual commissioning work with the automotive OEM, but looks to leverage that expertise across a variety of customers in other industries. “Though everyone wants to go faster, you can’t speed up things without first ensuring that the process is reliable,” Jones says.

‘(PLM) enables you to take PLC or HMI systems and programs and debug them virtually, verifying all faults before moving to the floor.’ –Andy Jones of system engineering firm Applied Manufacturing Technology

Production code from 3D drawings

A.T. Ferrell Company of Bluffton, IN, has been making equipment for cereal and grain processors for more than 140 years. It does its machinery design in Autodesk Inventor, a 3D CAD tool. “It gives us the opportunity to test different ideas while creating designs, to test functionality of the designs before we make prototypes or put them into production,” says Allen Gager, design engineer and CAD manager.

Once the design is final, A.T. Ferrell uses Edgecam, a third-party CAM tool, to open the design stored in the Autodesk Vault repository to create all production machining code directly from the 3D drawing. Edgecam “programs all the machine code necessary to produce that part. You can apply various functions to select types of tools you’ll need, the feed rates and RPMs,” Gager says. “Before, you’d have had to do it all manually. It’s a huge time savings, and you eliminate all translation errors previously caused by part geometry complexity.”

Increasingly, product design is becoming less an isolated, siloed process. “If you look at where innovation is coming from, it’s no longer simply a technical invention process done in the lab,” says Roy Wildeman, senior analyst for Cambridge, MA.-based Forrester Research. “It’s more the result of the intersection with other cross-functional areas like marketing and sales who more clearly understand customer requirements and the need for quality.”

Similarly, leading manufacturers are wanting downstream areas responsible for translating design into production processes—including manufacturing and process engineering—to become more seamlessly integrated into the process. “Desire to streamline the process has necessitated a link between product design itself and planning the manufacturing process needed to produce it,” says Marc Halpern, research director at Gartner. “When you design a product and create an engineering bills-of-material (eBOM), you want to give manufacturing sufficient lead time to create the production infrastructure to ramp to capacity as quickly as possible. Manufacturing process management (MPM) is the umbrella for this linkage.”

MPM is a key component of PLM, the digital pivot point between design engineering and manufacturing process engineering. (The “P” in the acronym alternately designates both manufacturing “product” and “process” management.)

“Manufacturing engineering is always interested in how things are going to be done,” says Francois Lamy, vice president of manufacturing product management for PTC. “Its function is to take engineering design data and create manufacturing information in terms of part structures for subassemblies, and for the design of workstations and lines required to produce them.”

The mBOM is where manufacturing process management comes alive. “The eBOM might clearly show that one part needs to be glued to another, but it might not specify the glue or the applicator,” says Halpern. Getting into the details of how and when in the process is at the heart of the mBOM.

MPM tools facilitate the ease and speed with which manufacturing engineers can take the eBOM and convert it into an mBOM, often using cut-and-paste functions that aid translation of product design into manufacturing processes. eBOMs and mBOMs basically have the same component elements and materials, but they’re organized differently toward achieving different ends.

With a tight, bi-directional link, manufacturing engineering might readily determine, for example, that screws would be a better fastening medium than glue. It then can digitally transmit this engineering change request back to design quickly, prompting a tweaking of the originating eBOM. A tight linkage also enables timely updating and notification of engineering change orders back into manufacturing, so production is always working to the latest version of design, improving efficiency and eliminating scrap.

‘Once you have the product definition and interdependencies with actual production processes captured and understood, workflow manages the change process in terms of automating the routing and approval process.’ –Roy Wildeman of Forrested Research

Workflow synchronization

Workflow is an elemental technology in this bi-directional communication. “Workflows have expanded overtime to reach outside of engineering design into manufacturing, so manufacturing can see what changes are occurring. Once you have the product definition and interdependencies with actual production processes captured and understood, workflow manages the change process in terms of automating the routing and approval process,” says Wildeman.

“Manufacturers have always struggled with keeping the manufacturing BOM in synch with the engineering BOM,” says Dave Shuey, director of marketing for Siemens PLM Tecnomatix product. “This is a non-trivial issue. People don’t always appreciate the delays that changes in the engineering bills-of-material can cause in the production process.”

The non-trivial nature of synchronization includes not only the eBOM/mBOM issue, but also the full scope of the PLM vision for digital manufacturing. Challenges are many when it comes to the accurate translation of data from 3D geometry to parts lists, physical production processes, work instructions, and ultimately automation equipment control code.

“The key take away in talking about digital manufacturing is the vision for an end-to-end process. When you start to design a product, you have to look at a number of things, including how it will be manufactured,” says Dick Slansky, senior analyst/research director for PLM at ARC Advisory Group. “Digital manufacturing takes it all the way from design to production simulation, on down to automated execution on the line. This is the vision for PLM today.”

PLM’s integrated software modules, bi-directional data communications, and three-dimensional virtual environments are moving that vision closer to reality for manufacturers and system integrators in all industries.

Author Information

Frank O Smith is a contributing editor to Control Engineering.