By using ISA-95 standard terminology, a common language makes data exchange fluid and efficient, breaking down the islands of automation.
Are you also hearing alarm bells now? Isnt it true that the physical inventory is always correct?! It is risky if someone hasnt heeded the lesson of Magrittes pipe and considers the virtual, administrative world to be realityespecially when you let such a person work within a production environment where people do not work with data, but with dangerous machines, expensive materials, explosive environments, etc.
True, the IT department often is not very close to production. However, its equally true that many engineers are miles away from the IT world.
MES projects are essentially different from PLC-SCADA projects. They have many more stakeholders; therefore, communication is an extremely important point of concern for these projects. In ERP projects, it is quite common to implement extensive change management strategies, with kick-off sessions, newsletters, team-building days, train-the-trainer courses, etc. Within PLC-SCADA projects there is hardlyif anyattention paid to such activities, and therefore no budget for them either.
Whenever MES projects fail, it is almost always due to lack of communication. Therefore the lessons learned and best practices of ERP projects (especially the communication and change management part) can be valuable input for the success of future MES projects.
In short: IT departments can learn a lot from engineers, and engineers can learn a lot from their IT colleagues. Especially in case of MES, close collaboration is essential.
A Confusion of Tongues
OK, so we agree that the plant needs an integrated automation system for management of recipes, for finite capacity scheduling and for generating reportsin short, an MES system. Now it is time to decide what the detailed requirements for such a system are, and only after that, a solution can be chosen.
The input from many different people within the organization is required when specifying the user requirements. Production has a big say in this, but the maintenance department and QA/QC also have needs. And, of course, the IT department and engineering play an important role.
Another area of tension involves which functionality belongs in which system (ERP or MES?). These discussions are especially relevant for enterprises that have an SAP-only policy. Many SAP adepts are convinced that SAP is capable of anything. The one who has the loudest voice will win the discussion, and before you know it, the whole factory is using SAP, with all related disadvantages.
How are all these people going to communicate? Everybody views the process from their own perspectives. Each department uses completely different terms to describe the same thing. Moreover, people from production, maintenance and QA/QC are not automation specialists, and IT and engineering are not production specialists. Inevitably, this mix of needs, concerns, technical languages and cultures will result in a Babelic confusion of tongues.
In short, MES projects clearly have a strong need for guidelines and standard terminology. How should a specific word be interpreted? Where should we put responsibilities? Which functionality belongs in which system? Are there any best practices and lessons learned from other manufacturing companies that can be modeled?
In the 1990s, some software suppliers, consultants and industrial enterprises acknowledged this problem. They established the SP95 committee within ISA, with a goal to develop a standard for enterprise-control system integration. Several parts of this standard have already been published, and companies all over the world are applying it. ISA-95 is based on the best practices of pioneers.
ISA-95 is not an automation system, but a method, a way of working, thinking and communicating. The method is described in several documents, each around a hundred pages. These contain models (figures) and terminology you can use to analyze an individual manufacturing company. Each of the models focuses on specific integration aspects; they each illuminate the issue from a different perspective.
Communicating about a system can be difficult because different people in the same conversation often assign different meanings to general terms. ISA-95 defines words that relate to integrating enterprise and control systems. ISA-95 places this terminology within models, which make clear the relationships among the various terms.
Compare this principle with drawing a blueprint for a house. A blueprint depicts what the house will look like, with symbols for windows, doors, walls and roofs. The words window, door, wall and roof are familiar to all of us, and we use them to talk to each other about the house. Every house is different, and still we can depict and describe every house with the same symbols and words for doors, roofs, walls and windows. The same applies to ISA-95. No two manufacturing companies are alike, and yet you can use the ISA-95 models and terminology to talk with others about the companys functions, activities, responsibilities, information flows and so on.
Moreover, ISA-95 standardizes the information to be exchanged, which has led to ERP and MES software vendors now offering an ISA-95 interface definition instead of the traditional vendor-specific interface definition. As a result, it has become easier, not only on the level of human communication, but also on the technical level, to integrate systems from different vendors.
The objective of the ISA-95 standard is to reduce the cost, risk and errors associated with implementing interfaces between enterprise and control systems. The standard can also be used for definition of user requirements for MES systems. Moreover it simplifies the implementation of new MES systems so that the company in the end has enterprise and control systems that are well-integrated.
Market research by MESA, has made clear that many industrial companies intend to purchase an MES system in the short term. Lets hope that will change the situation and that there will be more and more plants in which the production managers know what is going on; in which operators are controlling the process instead of doing administration; plants that have no stock issues leading to production stops; in which IT and engineering work closely together; plants where people have made a sensible decision in dividing functionality over ERP and MES systems, andlast but not leastwhere the managing director, not the planner, is the boss!
Bianca Scholten is a fellow at Netherlands-based consultancy, Ordina, and author of The Road to Integration: A Guide to Applying the ISA-95 Standard in Manufacturing, ISA, 2007. She can be reached at Bianca.Scholten@Ordina.nl