03 October 2001
Manufacturerís needs not changing but acronyms are
by Keith Unger
Move over, CIM. Today itís ERP, MRP, MES, REPAC, and SCOR.
There is a new landscape in manufacturing applications. The computer-integrated manufacturing (CIM) pyramid of the 1980s has crumbled to make way for a variety of better models for manufacturing information technology in the 2000s.
The Supply Chain Operations Reference (SCOR) model; the Manufacturing Execution Systems Association (MESA) model; and AMR Researchís Ready, Execute, Process, Analyze, and Coordinate (REPAC) model all define manufacturing applications from a functional point of view. Meanwhile, you can define manufacturing applications from the point of view of vertical markets, specific implementation models, and a broad range of functional categories.
In addition, manufacturing applications have evolved from custom solutions to tool kits to commercial, off-the-shelf packages.
And that is in addition to the functions that manufacturing applications provide for supply-chain coordination, enterprise resource planning (ERP) connectivity, planning, scheduling, inventory management, and shop floor data collection.
There have been many acronyms and models in the past two decades that describe the topic of manufacturing application software. However, regardless of naming and modeling, manufacturingís fundamental needs have not changed significantly. What has changed is the availability of commercial software, experience in applying software applications to manufacturing, and the emergence of standards for applying software and computer technology to manufacturing.
Today, many well-developed tools are available that can be successfully applied to meet the functional needs of manufacturing processes.
Experience gained applying software and computers to manufacturing has been well documented, and international standards communicate generally accepted best practices in manufacturing systems integration. Manufacturers today can take advantage of experience gained from early adoptersí efforts and apply current technology with a high degree of confidence that the application will successfully meet requirements.
In the 1980s, industry movers and shakers introduced the concept of CIM, and the CIM manufacturing software pyramid model was developed.
The CIM pyramid model focused on the hierarchy of the manufacturing enterprise. It divided the manufacturing domain into five levels of computing functionality. During this time frame, technology tools fit one or more CIM levels. Programmable logic controllers and loop controllers became the dominant technologies at the control level, and a whole market of supervisory control and data acquisition suppliers emerged to fill the needs of level two supervisory systems.
Corporate financial systems and functionality needed to support overall operations resided at the top of the pyramid. At the divisional level of the pyramid, the focus was on material requirements planning to meet customer orders. This planning process estimated capacity and material requirements based on a combination of forecast orders and actual orders for a specified time.
MES Systems Emerge
In the first half of the 1990s, new pressures and ideas began to change the shape of the CIM pyramid. Manufacturing was moving from an internal focus to a customer focus. Global pressure to compete for customer loyalty with high-quality products delivered when and where customers wanted the products required manufacturers to be more responsive. As a result of these pressures and ideas, the CIM pyramid collapsed and flattened out, and the new MES model evolved.
In 1992, Cambridge, Mass.Ėbased AMR Research introduced the three-layer MES model. This model reduced the manufacturing system problem set to three functional areas of planning, execution, and control. The model helped the industry by simplifying the number of levels and focusing on the need to link the planning process to the control process through a newly defined execution process.
MESA International developed a model of MES that identifies 11 core execution functional areas with interfaces to the enterprise-level planning and scheduling functions. Many of the functional areas MESA International identified have developed into mature product markets with commercially available solutions and well-defined functionality.
Today, just past the turn of the new century, continued global pressures for rapid response to consumer demand has changed the enterprise focus from internal planning, execution, and control to one of customer relationship management, supply-chain management (SCM), and product life-cycle management. Models evolved to support these new manufacturing requirements.
AMR Research combined the MES model with the SCOR model, creating the REPAC model, first proposed by AMR in 1998. The SCOR model reduces the complexity of the supply chain to the fundamental activities of Source, Make, and Deliver, with an overarching Plan activity to coordinate the entire supply chain. The REPAC model focuses on the SCOR Make activity, combined with the Execution and Controls activities from the earlier MES model. The REPAC model includes Ready, Analyze, and Coordinate activities required by the agile autonomous manufacturing facility.
The Ready function prepares the production process for operation and takes care of administering process improvements and engineering change orders. This includes transforming product specifications into detailed instructions needed to introduce a new product into the plant and corrective action for product or process exceptions.
The Execute activity completes work orders according to a production schedule. This includes initiation of the process setup to make a specific product, as well as executing the actual process and managing the schedule for automating and controlling the process. The Execute process communicates needs on a plant basis and records actual work order progress, including quality and exception conditions.
The Analyze activity evaluates actual production performance and product quality. It also measures process capability and evaluates regulatory compliance. The Analyze process summarizes real-time data and calculates key performance indicators for operators and manufacturing decision makers. It combines data from multiple execution components and assembles data as needed for ERP and SCM processes, including feedback to ERP on actual order progress, and resource consumption. It reports back to suppliers on material performance and supplies data, such as certificates of analysis, needed to meet the requirements for a specific customer.
The Coordinate activity balances plant operations within the overall enterprise and the extended supply chain. It optimizes plant activities to fulfill production demand and continuously updates the production schedule with current accurate data. This process also coordinates the material-receiving function from sources and coordinates production with distribution to feed SCOR delivery process.
Better models are not the only difference in manufacturing information technology since the 1980s. Manufacturing applications have also evolved from custom solutions to tool kits to commercial, off-the-shelf packages.
Today, applications include product life-cycle management systems; quality management, tracking, and genealogy; specification management and laboratory management; key performance indicator and business performance analysis systems; and decision support systems. That is in addition to functions manufacturing applications provide for supply chain coordination, ERP connectivity, planning, scheduling, inventory management, and shop floor data collection.
Functional integration is the most difficult challenge to making corporate and manufacturing systems work together. Before a manufacturer can attempt integration, the functional split has to be determined. Without a standard, most manufacturers should plan to do a lot of work assigning functionality in a way that meets their requirements.
An example is the product bill of material (BOM). To use the ERP system for financial reporting and the manufacturing systemís S88 Batch Recipe Formula, both systems may need a BOM in their respective data models to work effectively.
Standard Defines Split
Fortunately, there is an industry standard that defines the split between ERP and MES systems. This standard is ANSA/ISA-95.00.01-2000, Enterprise-Control System Integration Part 1: Models and terminology.
The standard is a great help in defining the requirements for integration of enterprise systems and manufacturing execution systems. The work included in this standard builds on the original Purdue CIM model (the source of the CIM pyramid), includes the MESA International model for MES, and defines a set of models and terminology to reduce the risks, costs, and errors associated with implementing enterprise-control system interfaces.
The S95 standard is a logical model of the enterprise and shows all functional areas as ovals. (Functions shown as rectangles exist but are outside the scope of the standard.)
The shaded (blue) area indicates the boundary of functionality within the scope of the manufacturing control system domain. This boundary defines the cut in functionality referred to previously. Lines with arrows indicate information flow between functional areas. Any line that crosses the shaded boundary is a flow of information that works within the scope of the S95 standard for enterprise and control system integration and is a solid line. Dotted lines do not cross this boundary and are not included as necessary information flows for enterprise and control system integration. Manufacturers can save time in their design by following the S95 standard and specifying that their ERP and MES vendors also adhere to the standard.
Manufacturers get all the one-size-fits-all claims from newcomers and established vendors of all sizes. In this new landscape of manufacturing applications, to further the goals of improved productivity, increased capital effectiveness, and reduced waste, manufacturers must push for a few basic yet revolutionary concepts. They need manufacturing applications that work well with ERP and supply chain systems and provide a single integrated MES architecture that supports the business processes associated with manufacturing.
There is a growing realization that e-business and supply chain strategies are converging with manufacturing operations to form an integral part of an overall collaborative business process. Collaboration among functional departments within an enterprise and with external partners requires robust information exchanges with well-defined exchange content. Manufacturers need solutions that can easily integrate with existing systems and that will help them become more flexible, react quickly, and respond effectively to the demands of todayís e-commerce world. IC
Figures and Graphics
- AMR model of 1990s
- ANSI/ISA95.00.01, Functional enterprise-control model
- Manufacturerís needs not changing but acronyms are (pdf version)
- MESA International MES model
Keith Unger is principal consultant for EnteGreat Inc., a Birmingham, Ala., consulting and systems integration firm. He is chairman of ISAís SP95 standard committee, former vice chairman of ISAís SP88 standard committee, and former World Batch Forum marketing chairman.
Return to Previous Page