ISA-95.01 Models & Terminology
Part 1 of ISA-95: "Enterprise Control System Integration 1: Models and terminology" (ANSI/ISA-95.00.01-2000)
Part 1 of ISA-95 consists of models with standard terminology. The models can be used to define the exact boundary of the enterprise systems and the control systems. Which tasks are executed by which function? And which information must be exchanged from where to where? These questions can be answered by using the models and terminology of part 1 of the ISA-95 standard.
Hierarchical model
The different models all focus on a specific aspect of the integration requirements. For example: there is a model that depicts the different levels of a manufacturing enterprise. This gives a clear picture of where in a specific company, in which department and by which system specific activities take place.
Functional model
There is a functional model, which can be used to define which functions are executed within the company, at which department and which system is responsible for the execution of this function. You can also use it to find the local names for the functions. Compared to the hierarchical model, the functional model focuses on functions, without taking into account the different levels within the enterprise. By combining the hierarchical and functional model, you will get a complete view of the company.
Information flows
The functional model clarifies which information flows from one function to another. ISA-95 has determined standard terms for these information flows. You can use these to decide what are the local names of these information flows, for example the name used by the ERP system, or the name used by the Scheduling system. You already know which functions are performed by which systems, so now it becomes clear which information flows are involved in the interface.
Categories and objects
Interface information can be divided into three categories. It typically consists of information is concerning Production capacity, Product definition or Production. This, in turn, consists of the object’s Equipment (tools, machines, devices, etc.), Personnel (people with certain skills) and Material (raw materials, energy, end products, waste materials, etc). Every information flow is built up from one or more of these 3 resources. ISA-95 defines object models for these resources, which can be used to exchange the information. The resource object models are the basis for a consistent set of more complex object models that make logical groups of the information that has to be exchanged.
Conclusion
ISA-95.01 is an excellent method to determine which information must be exchanged between enterprise systems and production control systems. The object models of part 1 are the basis for part 2 of the standard (ISA-95.02), which defines the attributes for the objects defined in part 1.