1、i By Bianca ScholtenThe Road to IntegrationA Guide to Applying the ISA-95 Standard in Manufacturing01-02 Title page.indd 1 18-01-2007 13:32:33ii 01-02 Title page.indd 2 18-01-2007 13:32:33iii Author Bianca ScholtenImages Bettina Logge-Mensing Layout it is not a goal in itself. In production automati
2、on projects, good communication with the systems end user is essential. In projects focused on integrating ERP and PCS systems, a large number of departments is usually involved, such as production, maintenance, the lab, and the ofce. Try speaking the same language then! The above indicates that in
3、recent decades, companies have been confronted with a gap between the ERP and PCS layers, and when trying to bridge this gap, problems have arisen in communication between people, and also between systems. Against this backdrop, ISA decided in the 1990s to develop a standard for integrating enterpri
4、se and control systems in order to reduce the risks, costs, and errors that go hand in hand with implementing interfaces between such systems. ISA is a global non-prot organization. Originally, ISA stood for Instrument Society of America, but this was changed to Instrumentation, Systems, and Automat
5、ion Society in 2000. Since the end of 2005, ISA has employed the slogan “Setting the Standard for Automation.” ISA denes its key activities as standardization, certication, education and training, publications, conferences, and exhibitions in the eld of industrial automation. Examples of familiar an
6、d popular ISA standards are ISA-84 (Functional Safety: Safety Instrumented Systems for the Process Industry Sector), ISA-88 (Batch Control), and ISA-99 (Manufacturing and Control Systems Security). The subject of this book, ISA-95, is ISAs ninety-fth standard and bears the title Enterprise-Control S
7、ystem Integration.1.3 Objective and Content of ISA-95ISA-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 (gures) and terminology you can use to analyze an indi
8、vidual manufacturing company. Each of the models focuses on specic integration aspects; they each illuminate the issue from a different perspective. What is the value of these models? In his book Information Systems,a Steven Alter gives the following explanation of the use of models: A model is a us
9、eful representation of a specic situation or thing. Models are useful because they describe or mimic reality without dealing with every detail of it. They typically help people analyze a situation by combining a frame-works ideas with information about the specic situation being studied. . . . They
10、help us make sense of the worlds complexity.23-63 C 01.indd 27 12-02-2007 10:24:4528 The Road to Integration: A Guide to Applying the ISA-95 Standard in ManufacturingCommunicating about a system can be difcult, because different people in the same conversation often assign different meanings to gene
11、ral terms. ISA-95 denes 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. You can compare this principle with drawing a blueprint for a house. A blueprint depicts what the house w
12、ill 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 do
13、ors, 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 ows, and so on.Moreover, ISA-95 standardizes the inf
14、ormation to be exchanged, which has led to ERP and MES software now offering an ISA-95 interface denition instead of the traditional vendor-specic interface denition. As a result, it has become easier not only on the level of human communication, but also on the technical level, to integrate systems
15、 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.bThe standard can be used to simplify the implementation of new software products and to ultimately have enterprise an
16、d control systems that interoperate and easily integrate. ISA-95 itself denes a number of potential advantages. For example, the standard makes it possible for software vendors to offer appropriate tools for integrating enterprise and control systems. The standard also makes it easier for end users
17、to map out their requirements and their nice-to-haves. Other potential advantages concern integration in general, such as lowering the cost of production processes and optimizing the supply chain. ISA-95 comprises several parts, each of which concentrates on specic aspects of the integration issue.
18、Some parts are still in development and it is not unthinkable that in the future, new - currently unforeseen - parts will be developed. These new parts will focus on yet other aspects of integration. This book covers exclusively the parts known at the time of writing: parts 1, 2, 3, and 5 (part 4 is
19、 still being developed). Visit www.isa.org for the most current state of affairs.1.3.1 Part 1Part 1 of ISA-95 is titled Enterprise-Control System Integration Part 1: Models and Terminology. Part 1 presents various models and terminology you can use in preparing and executing projects where the autom
20、ation of information exchange between ERP and MES systems is central. The most important models in Part 1 are the Functional Hierarchy Model, the Equipment Hierarchy Model, the Functional Enterprise-Control Model, the Object Models, and the Categories of Information Exchange Model. Subsequent chapte
21、rs will discuss in detail the 23-63 C 01.indd 28 12-02-2007 10:24:4529Chapter 1: Getting Acquainted with ISA-95practical application of the models. To be able to apply the models in practice, its essential to understand them well. This chapter therefore explains the most important models.1.3.1.1 The
22、 Functional Hierarchy ModelFigure 2 depicts the different levels of a functional hierarchy model: business planning the PCS layer has time horizons of hours, minutes, seconds, and even more nely grained. Now the different levels have been introduced, well dispense with the interpretation-sensitive a
23、cronyms ERP and Level 4Level 3Levels2,1,0Business Planning in other words, between Level 3 and Level 4.1.3.1.2 The Equipment Hierarchy ModelThe physical assets of an enterprise involved in manufacturing are usually organized in a hierarchical fashion as described in gure 3. . . . This model de nes t
24、he areas of responsibility for the different function levels de ned in the functional hierarchy model. The equipment hierarchy model additionally de nes some of the objects utilized in information exchange between functions.dIf youre familiar with Part 1 of ISA-95, youll notice that the model given
25、here is not exactly the same as the model in Part 1. That model has since been superseded by the more extensive model in Part 3 (see gure 3).This Equipment Hierarchy Model makes clear that the physical assets of manufacturing companies can be divided into different levels. At the Enterprise level, w
26、e have the company name, such as Johnson and Johnson. The Enterprise can comprise one or more Sites, such as the Johnson and Johnson Sites in Geel, Belgium; Schaffhausen, Switzerland; and Cork, Ireland. We typically indicate Sites using the name of the city. A Site can further contain one or more Ar
27、eas, which you can interpret as manufacturing departments. For example, Philip EnterpriseProcessCellUnit UnitWorkCellStorageUnitProductionUnitProductionLineStorageZoneWorkCentersWorkUnitsAreaSiteFigure 3: ISA-95 The expanded Equipment Hierarchy model (simpli ed)23-63 C 01.indd 30 12-02-2007 10:24:47
