B2MML Explained

Why does the acronym B2MML look familiar?

B2MML (Business to Manufacturing Markup Language) is the XML (eXtensible Markup Language) implementation of the ANSI/ISA 95 standards (internationally, IEC/ISO 62264). Think of B2MML as XML applied to manufacturing data and processes. To date, XML has mostly been used in exchanging data between business-to-business applications. B2MML changes that. According to the B2MML caretakers, the World Batch Forum (WBF; Research Triangle Park, NC; www.wbf.org), B2MML helps integrate business systems, such as enterprise resource planning (ERP) and supply chain management systems, with manufacturing systems, such as control systems and manufacturing execution systems (MES).

Why XML?

XML describes data, thereby giving meaning to those data. B2MML extends XML to set up a grammar, a message structure, for manufacturing data and how manufacturing and business systems communicate. Applications can now call for data by name ("work order number") rather than by location (whatever number that's in WO_field).

Aren't there a lot of manufacturing processes to consider?

That's exactly what ISA-95 covers. ISA-95 defines the interface between the control and enterprise layers in a manufacturing operation. These "data models" describe the boundaries between processes (for instance, where resource planning ends and manufacturing execution begins), messages, the direction of those messages, and the data structures (the logic and types of messages) between plant floor and enterprise-wide systems. These data models cover the who, what, when, and where of production. B2MML labels the data elements in each of these models. For example, within the personnel model, there is PersonNameGroup, EmployeeGroup, Skill, and PersonnelQualification; within the equipment model, there is ItemMaser, and WorkCenter.

How does this work in practice?

Software vendors and systems integrators transform production and business processes into a set of XML schemas. These schema define the process according to the applicable ISA-95 object model and the specific XML Schema language (XSD) that describe that process. For example, in a typical MES/ERP interaction, the "production performance" object as defined by ISA-95 consists of several "production responses," which in turn consist of a collection of "segment responses." These responses contain actual production and consumption data. The .xsd message would explicitly define those data elements, contain those data, and request a particular action with those data. The message would include other information, such as about the message sender (for instance, equipment, process, and application ID number). 

What happens during software upgrades?

While software may change, data models should not, so software can be upgraded without affecting the XML connectors and adapters. However, because B2MML is not a standard-it's just an interpretation of a standard-a B2MML interface from one vendor will not necessarily be the same as that from another vendor for the same transaction(s). When a software platform changes, say from one vendor's database to another, then the systems integrator (sometimes the database vendor) will have to map the data fields between the systems exchanging transactions. This typically requires revising the structured query language statements that interact with the XML connectors.

What are the benefits?

Standard, common definitions for data and processes in B2MML reduce the duplication in matching data from different software applications and business processes. This, in turn, provides low-maintenance interoperability between information systems, reduces the costs and risks of systems integration, and increases the flexibility of integrating disparate production and enterprise management systems throughout a manufacturing enterprise and its supply chain. B2MML is one of the ingredients that makes it possible for the recently announced integration of the Production Management system from GE Fanuc Automation, Inc. (Charlottesville, VA; www.gefanuc.com/en/Industries/Automotive/index.html) and the ERP systems from SAP (Newtown Square, PA; www.sap.com). In this case, the two suppliers have already worked out all the B2MML messages between their respective systems.