ISO/TS 81346-3

ISO/TS 81346-3, Industrial systems, installations and equipment and industrial products 

— Structuring  principles and reference designations 

— Part 3: Application rules for a reference designation system

Consequently, ISO/TS 81346-3:

 offers broadly based, general solutions with rules for a practice-oriented and consistent application;

 fulfils the requirements for ergonomics and occupational safety;

 takes into account memorability, labelling, and processing in common office- and CAx-tools;

 summarizes in a single document all technical designation tasks (reference designations according to function, product and location aspect as well as designation of connections, signals, documents);

 recommends decoupling of reference designation activities of plant designers and of equipment suppliers, by use and allocation of different aspects;

 introduces the “conjoint designation” for higher level objects without specific aspect;

 supports the handling of computer programs and parts of such programs as technical products;

 forms the basis for sector-specific solutions and specifications in further parts, in order to achieve a consistent designation across different technical fields.

The designation of types, individuals, cost-centres, projects, etc. is not covered by this part of ISO 81346.

3.4

document

information on a data medium

NOTE 1 Normally a document is designated in accordance with the type of information and the form of presentation, for example overview diagram, connection table, function chart.

NOTE 2 Information can appear in static manner on paper and microform, or dynamically on (video) display devices.

[IEC 61082-1:2006]

3.7

documentation

collection of documents assigned to a specific object

NOTE This can include technical, commercial and/or other documents.

[IEC 61082-1:2006]

3.12

plant

complete set of technical equipment and facilities for solving a defined technical task

NOTE A plant includes apparatus, machines, instruments, devices, means of transportation, control equipment and

other operating equipment.

[IEC 60050-351:2006]

3.14

product

intended or accomplished result of labour, or of a natural or artificial process

[IEC 81346-1:2009]

3.18

structure

relations among the elements of a system

[IEC 60050-351:2006]

3.19

system

set of interrelated objects considered in a defined context as a whole and separated from their environment

NOTE 1 A system is generally defined with the view of achieving a given objective, e.g. by performing a definite function.

NOTE 2 Elements of a system may be natural or man-made material objects, as well as modes of thinking and the results thereof (e.g. form of organisation, mathematical methods, programming languages).

NOTE 3 The system is considered to be separated from the environment and from the other external systems by an imaginary surface, which cuts the links between them and the system.

NOTE 4 The term "system" should be qualified when it is not clear from the context to what it refers, e.g. control system, colorimetric system, system of units, transmission system.

NOTE 5 When a system is part of another system, it may be considered as an object as defined in this standard.

[IEC 81346-1:2009]

fulfilment of ergonomic principles in accordance with ISO 12100, ISO 9355-1 and ISO 9355-2, with regard to occupational health and safety (hazard analysis, fault tracing, job orders, equipment release procedures, etc.), e.g.

 simple structure of designation,

 easy-to-remember representation,

 clear legibility and easy memorability,

 error-free interpretation;

The designation shall clearly and unambiguously identify all objects and associated information according to their function, implementation and location.

The designation shall describe the real structure of an object and its relations to other objects.

The designation of the parts of a system shall be generic to such an extent that the system can be

incorporated in any other system, without the need for changing the reference designations in any of the systems involved.

For a specific project, the general rules shall be listed at the start of the designation process and documented complete with specific requirements in separate instructions.

4.1.6 An example of a designation process within a project is given in Annex A. Application examples are given in Annex B. Other terms and definitions that are used in the context of a “designation system” and will be helpful for the elaboration of sector-specific parts of this International Standard are given in Annex C.

Designation process

The designation process comprises the following sub-processes.

Starting from process flow diagrams, overview diagrams, site plans, etc. used to describe the structure of the overall project in accordance with IEC 81346-1, the overall object shall be broken down according to different viewpoints. For instance, a location with industrial facilities can be divided into specific areas (e.g.

manufacture, power plant). These objects shall be defined as top-level nodes of the overall structure and shall serve as starting point for subdivisions into lower-level aspect-oriented structures (see 5.3.1).

At an early stage in the planning, the task-oriented representations of the object of interest shall be translated into a hierarchical tree-like structure under a functional aspect. In subsequent phases, the products that fulfil the tasks of the partial objects viewed under functional aspects shall be defined and structured. 

To designate the location of the products, the overall object shall be structured under the location aspect. Structuring shall be performed in compliance with the principle of constituency, i.e. an object is a constituent of a single higher object, but can comprise several sub-objects (hierarchical structural model). The subdividing process is completed with the smallest object of interest for the defined purpose.

Partial objects shall be defined and classified during the structuring process. To classify partial objects, it is possible to use IEC 81346-2:2009, Table 1, for non aspect-specific purposes and/or sector- or project-specific letter code tables structured in accordance with IEC 81346-2:2009, Table 2. In cases where both methods are used, the allocations of the structural level to the corresponding letter code level shall be defined. The parts of an object shall be classified in accordance with their location in the structure (structural level), as specified by the agreed tables.

The prefix for the aspect, the letter code of the object class and an additional number form the single-level reference designation. The number is used to distinguish between objects belonging to the same class and to the same overall object. The multi-level reference designation is created by concatenating the single-level reference designations represented in the path beginning with the top-most one.

To establish a unique designation, it is necessary to create task-specific designation combinations (in relation to technical objects, signals, connections, documents), as described in Clause 6.

The designation shall be used for labelling technical objects in the plant, for designating documents and for identifying the representation of objects in documents.

Reference designations with different aspects can be used in databases to network object information in different records (“pragmatic relations”). This yields a large number of task-related evaluation options, e.g. information about the location of products performing a function and which are reported as defective.

Figure 1 shows the schematic representation of the designation process.

5.1 General

A reference designation shall

 identify an object,

 provide information regarding the class to which the object belongs, and

 provide information on where the object is located within a structure.

5.2 Conjoint designation

It is recognized that on a site different plants may exist. In order to address these plants with respect to the site, it may be necessary to apply a conjoint designation. A conjoint designation is a reference designation of a plant/system with respect to the site, which is not related to one of the defined aspects.

NOTE In IEC 81346-1, the aspect type “other aspect" (for aspects see 5.3.1.1) is introduced together with the prefix sign “#”. Conjoint designation is considered as one of the “other aspect” types.

A system, and each constituent object, can be viewed in many ways, called “aspects” (see Figure 3).

Questions:

 What does the object do? (function aspect)

 How is the object constructed? (product aspect)

 Where is the object located? (location aspect)

The function aspect shall be based on the purpose of the system, without necessarily taking into account the products used to fulfil this purpose or their location.

The designation based on the function aspect is preferably performed in the early planning phase of a project without taking implementation into account. Normally, this type of designation is first used by the planner of the overall process (top-down approach).

It is often expedient to use different aspects for the same object. Different aspects of successive objects may be used by making a transition from one aspect to another. 

The most frequent application of this method is the transition from the function to the product aspect when a function is completely implemented by a product, and when there is no sub-product that by itself completely implements the function.

Figure 5 shows the transition from the function aspect to the product aspect, and presents the difference between transition and allocation.

Documents provide information necessary for different activities and purposes during the life cycle of a plant, system or equipment.

The three parts of the identifier are:

 conjoint designation (see 6.2);

 reference designation (see 6.3);

 specific designation (see 6.4).

If the conjoint designation is used, it shall form the first part of the identifier.

If requirements for ergonomics and occupational safety (e.g. legibility, memorability, error-free interpretation) are to be fulfilled, the single-level reference designation shall be constructed as shown in Figure 8.

To satisfy the needs of legibility and memorability, there should not be more than three letters or numbers.

The specific designation shall designate:

 signal names, in accordance with IEC 61175;

 electrical, mechanical and functional terminals, in accordance with IEC 61666;

 document kinds, in accordance with IEC 61355-1.

At the beginning of a project, the designation-relevant stipulations indicated in Table A.1 should be respected.

Table A.4 — Infrastructure objects

The classes of infrastructure objects (level L1 in Table A.3) are based on the rules of IEC 81346-2:2009, 5.3 and Table 3. 

Table A.4 gives examples of infrastructure objects of a chemical plant according to IEC 81346-2:2009, Table 4.

For levels L2, L3 and L4 in Table A.3, the object classes according to IEC 81346-2:2009, Table 2, should be used. 

Table A.5 gives examples of letter codes for the classification of aspect-oriented structures.

For classes of location aspect oriented objects (++, see Table A.1), the codes given in Table A.6 are used in the application examples in Clause A.3.

The function aspect is the dominant aspect in the structuring of process engineering. 

The structuring and designation process are in accordance with ISO 10628.

Figure A.3 — Block diagram of chemical plant 3 (#CP3)

Figure A.6 shows a part of a power supply system (distribution, transformation). The structuring levels L1 and L2 including the conjoint designation (#CP3) are represented, as well as distribution in the part-process distillation (=F1).

Figure A.9 shows the measured data acquisition in the process, the signal processing and process control as a function diagram. The structural levels L3 and L4 are represented, as well as a transition from function to product aspect.

B.3 Functional allocation (SUPER!!)

Figure B.4 — Subsystem with terminals on tank, pump, valves and piping

Other helpful terms and definitions for a “designation system”

C.5

associative relation

pragmatic relation

relation between two concepts having a non-hierarchical thematic connection by virtue of experience

NOTE An associative relation exists between the concepts “education” and “teaching”, “baking” and “oven”.

classification system

indexing language with assigned notations

[ISO 5127:2001]