01 April 2003
Feeding the resource planning beast
SP95 brings manufacturing relief.
By Ellen Fussell
"THE scariest thing a manufacturer can hear is, 'We've just started a job to integrate ERP systems into the factory,' " said Dennis Brandl, president of BR&L Consulting in Cary, N.C., and chairman of ISA's SP95 standards committee, Enterprise/Control Integration.
It's scary because enterprise resource planning (ERP) is tricky business, especially when manufacturers have multiple plants whose processes change continuously. But standardizing the formats and language that surround the conglomeration of data needed to run the process is one way to make life easier for the manufacturing side of the enterprise—so it doesn't have to worry about the business aspect of the ERP systems.
Part III and internal needs
Whereas Parts I and II of the ISA-95 series of standards are focused on the enterprise and manufacturing, Part III is inwardly focused, said Keith Unger, senior business consultant at Rockwell Automation in Atlanta. It defines generating a common model for manufacturing operations activities—what's commonly known as manufacturing execution systems (MES).
"We're now calling it activity models of manufacturing operations," he said. "Part III focuses on the activities that go on inside manufacturing in order to manage the process of making a product, from receiving raw materials to producing finished goods. It defines a generic model of a production operations model—how to make a product."
Among nine basic activity levels, only four of them interface to the enterprise level. To coincide with the product definition interface level, one of the nine activities is product definition management. A part that addresses production resource management coincides with the product capability level. There's a scheduling interface that coincides with the enterprise production schedule. Inside manufacturing operations, there's a corresponding activity known as detailed production scheduling.
"This helps the customer define what their systems are, their requirements," Unger said. "I'm consulting with a customer to define what they call MES. Right now we're defining their requirements, following the ISA-95 standard. It gives you a way to talk about the user requirements and organize them into a common category of activities closely related," he said.
"The standard helps you organize your thoughts when you're defining the requirements: either integrating an existing facility or adding new functions to a facility or ongoing support."
Part I of the series defines a standard way of looking at how information flows between the manufacturing and business realm of the company. Whether a production request comes from SAP's ERP system, Oracle, or Bond, it's just as clear to the business side as it is to the manufacturing side of the enterprise because it uses one standardized language. (SAP produces integration and application platforms that enable companies to manage the entire value chain across business networks.) ANSI/ISA-95.00.01-2000, Enterprise-Control System Integration, Part I, Models and Terminology, provides a "standard model of data—what the product reports look like, regardless of the vendor it comes from," Brandl said.
That's good for the business because changes happen all the time, and manufacturing doesn't want those changes to ripple through to the business systems and clog the process. And because most companies with multiple plants are international companies, the standard is now approved by the International Organization for Standardization and the International Electrotechnical Commission. "So manufacturers can say their plants follow the international standard," he said.
The second standard in the series, ANSI/ISA-95.00.02-2001, Enterprise-Control System Integration, Part 2: Object Model Attributes, contains additional details and examples to help explain and illustrate the Part 1 objects. Yet Brandl admitted there's still some confusion regarding the standard. "People try to identify the interaction between manufacturing and logistics," he said. essentially, manufacturers want all plants to look the same to the ERP systems and the ERP systems to look the same to the plants."
ERP BUSINESS ACTIVITIES
Before ISA-95, in the past 10 years, companies would roll out ERP systems and want to hook them with the manufacturing systems.
"But these systems are data beasts," Brandl said. While manufacturing has plenty of data to feed the beasts, "it costs a lot of money to do it manually," he said.
One of the business activities that require constant feedings is activity-based costing: determining how much money it will cost to make a product and which product is more profitable. "They have to factor in everything," Brandl said. The standard provides an international standardized way for vendors to supply that information—a standardized format for feeding data to the system. "A good way to think of it is how a check has specific fields," he said. If everyone's check format were different, the entire banking system wouldn't be half as efficient.
Another business process that adds to the potential confusion is called available to promise. It's essentially the process whereby a vendor can promise a customer a certain amount of product based on what manufacturing says is available. It's important to make sure the information is correct because manufacturers are penalized if they can't meet their promises. "The process has always gone on, but it's so hard to get visibility in manufacturing," Brandl said. "In the old days, the information needed sat on the manufacturing floor."
But with the ISA-95 standard, a structure is in place to communicate that information more clearly. Companies such as AspenTech and ABB might be communicating information from several different vendors, but with the standard, "they can use one format—write one way—to the ERP vendors such as JD Edwards, SAP, or Oracle," Brandl said.
Parts I and II are already simplifying processes, but the committee isn't stopping there. Members met in February to hash out Part III, which shows the activity models and data flows for manufacturers (see accompanying sidebar on Part III). Part III "helps give vendors a common vocabulary to describe solutions to customers so they'll more easily understand," Brandl said.
Plus, it should help reduce the risk, the cost, and the errors associated with implementing enterprise systems and manufacturing operation systems that interoperate.
XML in batch communication
The XML data file has information (depending on the components you're integrating) to help users integrate a batch control system to an ERP system. It describes how that data looks, telling users what the raw material is and how much there is, and it's in a format that both applications understand. The XML schema is an agreed-on format designed to pass information back and forth between the business planning system and the execution system that sits on the factory floor.
ISA's SP95 committee is writing the standard that says these are the things to consider when you're doing this integration.
"Their first concern is safety because they don't want the business system to be able to send instructions to the manufacturing system to cause it to do something unsafe," said Bob Babecki, Foxboro's product manager in Foxborough, Mass.
"Some people have an idea that planning systems should control the manufacturing very tightly—even tell it which valves to open. That's generally not a good idea because the planning system is not a real-time system," Babecki said. "You need real-time information in order to know what the proper state of any valve is at any given time. So those decisions need to rest in manufacturing."
Babecki said the details need to go to the people on the factory floor who know how to make the product. "That knowledge is embedded in manufacturing systems. The ISA-95 standard addresses how you integrate business systems and manufacturing systems. And you don't want the business systems to create a unsafe condition."
While Parts I and II of the ISA-95 series define a format for exchanging data, "that's not something software can directly use," Brandl said. So the World Batch Forum is developing extensible markup language (XML) schemas that contain Parts I and II data models. Food manufacturers are working with ERP vendors, looking for standard XML schema to exchange data between ERP and manufacturing systems.
The SP95 group defined those data schema that describe what information enterprise and manufacturing systems need to share. "What is the relationship between the pieces of data, and what does that data mean? Manufacturing needs to know how many people and how much material and equipment it takes to make a product. So ISA-95 defines a data schema that would represent that information," said Keith Unger, senior business consultant at Rockwell Automation in Atlanta.
"Remember, ISA-95 doesn't tell you how to do it; it just specifies what you need to do, and it specifies a data schema," he said. The schema is the representation of data that manufacturers need to transfer among parts of the enterprise, whether it's high-level scheduling functions or plant-level data needs. For the end user, the standard helps define your information needs.
The whole purpose of ISA-95 was to reduce the cost and risks associated with enterprise manufacturing because there was no standard way to do it, Unger said. "Now there's an open, published, standard way to do this type of integration."
Companies use it to standardize their own internal way of answering those questions, or externally, where there are many partners involved. Manufacturers use it to define, design, and build systems to integrate their manufacturing floor: the execution layer and the enterprise layer.
"Companies are using it for internal integration of tools—bringing their own applications together and interfacing to applications not owned by one particular supplier," Unger said. "There's no one single computing system to answer all those questions, so there has to be some common interfaces. And that's what ISA-95 is attempting to do. By having a standard, we're all designing to the same set of common definitions for information we need to exchange."
FOUR INFORMATION EXCHANGES
Unger described four information exchanges the standard defines: "How do I make a product? Do I have the manufacturing capabilities? Can I package it? What's the schedule?" The fourth interface, performance information, gives feedback to the enterprise (also within the manufacturing layer). "What did I produce? How well did I produce it? What did it cost me? What were the materials, people, and equipment involved? That's the standard from the end user's point of view," he said.
But it doesn't just apply to manufacturing. Utilities industries use it, too.
"They all have the same basic needs. Here's what I want to make, when I want to make it, and where I want it to go. Where can I get it made? Who can make it most economically with the highest quality and get it to my customers? Think of the standard as a form," he said. Just like with XML, "when you print out the results of generating an XML implementation, you can actually read the results."
In the ISA-95 schema, there is a basic subset of questions. A product needs a name, description, and product identifier. ISA-95 says there is a minimum of things manufacturers need to communicate about a product. It defines nine object models or data schemas necessary to support those four interfaces. The XML schema have implemented those object models. IT