Structuring and Identification

Structuring of plants/installations and their information is essential for an efficient and easy manageable engineering, erection and running of a plant/installation involving many different technical disciplines, and to ensure a consistent documentation throughout the complete lifecycle.

Unambiguous identifiers of any objects in the plant/installation are the core to ensure consistency of the documentation and the correlation between the documentation and the physical objects in the plant/installation.

In the early days of TC3, the work was focused on development of graphical symbols. Without graphical symbols, representing the object to be described (documented), communication between different parties became difficult (if not impossible). Later, simple drawing rules were made, making presentation, i.e. circuit diagrams, more easily conveyable to different parties.

As installations become more and more complex, the need for more recognizable methods for identifying the component represented in diagrams, a method for identifying and a simple classification was introduced by the publication IEC 60113-2:1971.  At this time, the information on the installation was only given in documents, and the main focus with the publication was to allow easy cross-referencing within and between different diagrams.

IEC 60113-2 was replaced by IEC 60750:1983 were the focus was changed from handling of diagrams to be more relevant for documentation in general, i.e. all kind of documents. In many ways, it was recognized that structuring of information become more important than just labelling of components.

In 1996, IEC 61346-1 was issued. In this publication, the focus is on structuring of information and based on the structure, create unambiguous reference designations, i.e. identifiers. It was acknowledged that an object may be identified in different ways, depending on the available information. Information is not only given in documents, but is also maintained in databases too. The computerized world was acknowledged.

IEC 61346-1 did only deal with structuring and rules for creation of reference designation. The part of dealing with classification of objects for use in reference designation, IEC 61346-2 came in 1999.

IEC 61346-1 was, even if the principles were very general and discipline independent, considered to be an electrotechnical publication. Therefore, in 2009, the publication was revised in cooperation with ISO/TC10, focusing of making the publication more relevant for all technical disciplines. Also, the IEC 61346-2 was revised, incorporating object classes from other disciplines. The publications were issued as IEC 81346-1 and IEC 81346-2.

Classification of objects is a difficult issue, and it was recognized that the classification scheme of IEC 81346-2 had some disadvantages and not easy to implement for other disciplines than for system related to the electrotechnical and process industry domain. IEC 81346-2 has therefore been revised, providing a future friendly classification system while maintain the old o system (as far as possible). The classification system of IEC 81346-2 allows any object to be classified and supports therefor all disciplines involved in any kind of construction.

The IEC 61346 series allows any object in a design to be unambiguous identified by one or more reference designations, and each object can be classified with a life-cycle stable class code to be used in reference designation or other places.

The following figure below illustrates the development of the IEC 61346 series in relation to life-cycle and the application domains.