Introduction to ISO Standardization Process
 
Mark Lobo
Masters of Science Graduate Student
and
John W. Nazemetz, Ph.D.
Associate Professor
School of Industrial Engineering and Management
 Oklahoma State University
Stillwater, Oklahoma
This paper was developed under the Computer Assisted Technology Transfer (CATT) Research Program, Contract Number F34601-95-D-00376, Delivery Order: Engineering Assignment CATT-95-01.
 
Abstract

1.0 Introduction

1.1 What are Standards?

1.2 International Standardization: What do we achieve by it?

 2.0 International Organization for Standardization (ISO) 2.1 ISO Definition

2.2 History of ISO

How it all started

ISO Objective

General Assembly

Technical Management Board (TMB)

 3.0 U.S. Role in the World of Standards ANSI

ANSI and ISO

Mission and Goal in the International Arena IGES PDES Organization (IPO)

Structure

 4.0 How ISO Standards are developed Phases of developing standards

Phase 1

Phase 2

Phase 3

Sequence of the Project stages in the ISO Standards development process

Proposal Stage

Preparatory Stage

Committee Stage

Enquiry Stage

Approval Stage

Publication Stage

 5.0 Industrial Automation Standards Technical Committee 184 – Industrial Automation Systems and Integration

Technical Committee 184/ Subcommittee 4

Scope Membership

Organization of the SC4

SC4 Working Groups

Working Group 2 - Parts Library (P-LIB)

Working Group 3 - Product Modeling

Working Group 11 – Languages, Implementation and Testing.

Working Group 8 – Industrial Manufacturing Management data

Joint Working Group 9 – Electrical and Electronic Applications of ISO 10303

Working Group 10 – Technical Architecture

Working Group 12 - Common Resources

 SC4 Advisory Groups Policy and Planning Committee (PPC)[2]

Quality Committee

 Standards within ISO TC184/SC4

ISO 10303: STEP, the STandard for the Exchange of Product Model data.

ISO 13584 – Parts Library (PLIB)

ISO 14959 - Parametrics

ISO 15531 - The Industrial Manufacturing Management Data (MANDATE)

ISO 15926 - Integration of life-cycle data for oil and gas production facilities

 6.0 ISO STEP Standard Development Process Some Definitions

Application Protocols (AP)

Application Activity Model (AAM)

Application Reference Model (ARM)

Application Interpreted Model (AIM)

Integrated resources (IR)

Application Interpreted Constructs (AIC)

Conformance Classes

Abstract Test Suites (ATS)

Steps involved in putting a STEP standard together

Application Activity Model (AAM) Phase

Committee Draft for Comment (CDC) Phase

Committee Draft (CD) Phase

Draft International Standard (DIS) Phase

Final Draft International Standards (FDIS) Phase

International Standard (IS) Phase

 7.0 STEP Standards Development in the Future Development of STEP standards: the current situation

Scope of the Problem

Modularity is the Key

Status of STEP standards at ISO

STEP into the future

 8.0 Summary

 

List of Figures

Figure 1: Structure of ISO

Figure 2: IPO Structure

Figure 3: Structure of SC4
Abstract

Standardization is not just another "Buzzword". It has been around for quite a while. It is here to stay. Actually, standards seem to touch most aspects of our daily routines. The phone cards and credit cards that have become part of our everyday life, are perfect examples of standards at work. In fact, the thickness of 0.76mm on credit and phone cards, which confirms to an ISO Standard, ensures that these cards can be used worldwide. International standards contribute to making life simple, and to increasing the reliability and effectiveness of the goods and services we use.

This paper will trace the procedural aspects of putting together an ISO Standard. The entire process of putting together an International Standard is quite complex and time consuming, with a political twist.

Most of the work of the ISO is achieved in the Technical Committees (TC) and it's Sub-Committees (SC). The technical committee TC 184/SC4 is responsible for a set of standards. STEP, or STandard for the Exchange of Product Model data, is emerging as the standard for the future. This standard is still in the process of being developed and implemented.

There are still a few areas of STEP that are being revised although they are international standards. This shows that STEP as a standard is constantly evolving. The time frame for putting together an Application Protocol (AP) is about five years. There are other issues like the architecture of STEP that are being addressed. This paper will address this "problem" and give and insight to the solution being proposed.

This paper will end with a brief summary, which addresses the various issues regarding the ISO STEP Standard and its process of Development and implementation

Keywords: ISO 10303, STEP, ISO, TC, SC, AP

  1. Introduction
In trying to understand the process of developing international standards, one must definitely understand the concept of standard and standardization. The following section will elaborate on these areas, with a mention of the need for international standardization.

 

1.1 What are Standards? Standards are agreements, which are documented. They contain technical specifications or other precise criteria are used consistently as rules, guidelines, or definitions of characteristics. They ensure that materials, products, processes, and services are fit for their purpose.

For example, the thickness of the credit cards, phone cards, and "smart" cards that have become commonplace is governed by an ISO International Standard. Adhering to the standard means that every card will be 0.76 mm thick, ensuring that the cards can be used worldwide.[7]

International Standards contribute towards making life simple. They increase the reliability and effectiveness of the goods and services we use in every day life.

 

1.2 International Standardization: What do we achieve by it? Non-harmonized standards exist for distinctly similar technologies in different countries or geographic regions. These contribute to so-called ‘technical barriers to trade’. These "so-called barriers" influenced the export-minded industries to agree on and develop world standards to help rationalize the international trading process.

International standardization is now well established for very many technologies. The fields are as diverse as information processing and communications, textiles, packaging, distribution of goods, energy production and utilization, shipbuilding, banking and financial services. The standardization process will grow in importance for all areas of industrial activity.

The main reasons for International Standardization can be listed as follows[7]:

Industry-wide standardization exists within a particular industrial sector when the large majority of products or services conform to the same standards. It results from consensus agreements reached between all economic players in that industrial sectors namely suppliers, users, and often governments.

The aim of standardization is to facilitate trade, exchange of products and services, and technology transfer through [7]:

Users have more confidence in products and services that conform to International Standards. Assurance of conformity can be provided by manufacturers' declarations, or by audits carried out by independent bodies.
  1. International Organization for Standardization (ISO)
2.1 ISO Definition: The International Organization for Standardization (ISO) is a worldwide federation of national standards bodies from some 100 countries. Only one body from each country is allowed to represent that country.

ISO is a ‘non-governmental organization’ established in 1947 . The ISO was started with a mission to develop of standardization and related activities in the world with a view to facilitating the international exchange of goods and services, and to develop cooperation in intellectual, scientific, technological and economic activity. The ISO focussed on a "new world order" wherein boundaries and demographic constraints to business and trade were no longer present.

ISO's work results in international agreements, which are published as International Standards. ISO stands as the primary and leading body for standards development.

 

2.2 History of ISO International Standardization began in the electrotechnical field: The International Electrotechnical Commission (IEC) was created in 1906. The International Federation of the National Standardization Associations (ISA) was set up in 1926. Actually, the emphasis within ISA was laid heavily on Mechanical Engineering. [7] How it all started The Second World War saw the ISA shutting down. Following a meeting in London in 1946, delegates from 25 countries decided to create a new international organization "the object of which would be to facilitate the international coordination and unification of industrial standards". The new organization, ISO, began to function officially on 23 February 1947. The first ISO standard was published in 1951 with the title, "Standard reference temperature for industrial length measurement".[7] Strangely, that there does not seem to be any one-to-one relation between the full name "International Organization for Standardization" and the short form, ISO. The popular question asked is, shouldn't the acronym be "IOS"? Yes, if it were an acronym, which it is not.

In reality, "ISO" is a word, derived from the Greek word "isos", meaning "equal," which is the root of the prefix "iso-" that occurs in a host of terms, such as "isometric" ("of equal measure or dimensions" - Shorter Oxford English Dictionary) and "isosceles" (two sides of a triangle are equal). From "equal" to "standard", it was only reasonable that this line of thinking led to the choice of "ISO" as the name of the organization.

In addition, the name has the advantage of being valid in each of the organization's three official languages, English, French and Russian. The confusion that would arise through the use of an acronym is thus avoided; for example "IOS" would not correspond to the official title of the organization in French, ‘Organization Internationale de normalisation.’

 

ISO Objective The principal objective of the ISO is develop standards in the world so that the international exchange of goods and services is facilitated and cooperation in the sphere of intellectual, scientific, technological, and economic activity is developed.

In order to accomplish this, ISO may:

Take action to facilitate coordination and unification of national standards and issue necessary recommendations to national bodies for this purpose;

Set international standards;

Encourage and facilitate, when necessary, the development of new standards having common requirements for use in the national or international sphere;

Arrange for the exchange of information regarding work of its Member Bodies and technical committees;

Cooperate with other international organizations interested in related matters, particularly by undertaking, at their request, studies related to standardization projects.

Structure of ISO

The ISO consists of a number of different organizations. Each of these performs a different task. The following section explains the key elements of the ISO and their tasks.

The Structure of the ISO is best described by the figure shown below.

Figure 1: Structure of ISO
This figure has been extracted from http://www.iso.ch/infoe/isostr.html as of March 30, 1998

 

General Assembly The ISO is made up of three types of members. They are defined as follows

Member Bodies: It is a national body "most representative of standardization in its country". It follows that only one such body for each country is accepted for membership. For example: ANSI (U.S.A.)

Correspondent Members: An organization in a country that does not yet have a fully developed national standards activity. Correspondent members do not take an active part in the technical work, but are entitled to be kept fully informed about the work of interest to them. For example: JISM (Jordan)

Subscriber Members: ISO has established a third category of members for countries with very small economies. These subscribers pay reduced membership fees that nevertheless allow them to maintain contact with international standardization. For example: Cambodia

Council

The operations of ISO are governed by the Council consisting of the principal officers and eighteen-elected ‘member bodies’. The council appoints the Treasurer, the twelve members of the Technical Management Board, and the Chairmen of the policy development committees. It also decides on the annual budget of the Central Secretariat.

Technical Committees

The Technical committees (TC) are responsible for actual development of ISO standards. There are various technical committees, each with focussed interests, like TC 4: Roller Bearings. Most TCs have elected officers such as a Chairman and Secretariat. The scope of the TC is also defined extensively. The TC may have sub-committees that define individual standards, as in the ISO 15:1981 Rolling bearings-Radial bearings-Boundary dimensions-General plan.

Policy Development Committees

The Policy Development Committees as the name suggests new policies affecting the future of the ISO Community. There are presently four committees as defined below:

  Technical Management Board (TMB) The TMB consists mainly of representatives from the Member nations. They mainly focus on the following activities:  
  1. U.S. Role in the World of Standards
The United States has been pioneering the work of standards development since the inception of the ISO in 1947. There are many governmental bodies, industries, and academic institutions involved in the development and implementations of global standards. This section will mainly focus on the activities of two organizations that play a vital role in the standards community at both the national and international level. ANSI The American National Standards Institute or ANSI promotes using U.S. Standards internationally, advocates the U.S. policy and technical positions in international and regional standards organizations, and encourages adopting international standards as national standards where these meet the needs of the user community [9].

 

ANSI and ISO ANSI was one of the founding members of the ISO. ANSI is also one of the five permanent members of governing ISO Council and one of four permanent members of ISO’s Technical Management Board.

As the representative of the U.S., it is responsible for taking up standards at the ISO and IEC forums.

The primary focus of the ANSI is to promote global standards that reflect U.S. interests. Other goals of the organization are listed as follows   IGES PDES Organization (IPO) The IPO was created in the late 1970s to develop a neutral file format for the exchange of geometric data among different CAD systems. The IGES suite of standards was a result of this effort and accepted as an ANSI standard. IGES Version 5.3 was the last released version in 1996. This organization is accredited by the ANSI to represent the U.S. for STEP at the ISO level. They usually meet three times a year, usually at the same time as the ISO meetings.   Structure The IGES/PDES Organization (IPO) is a program area of US PRO. The IPO General Assembly consists primarily of individuals from government, industry, and academics. They are focussed toward standards and technology for the exchange of product information. There are two main areas of interest:
The IPO plays a vital role in activities relating to merging the IGES standard with the STEP standard. The IPO has links with ANSI to discuss matters relating to STEP as an international standard. The IPO is responsible for IGES Project as well as the PDES Project. It also monitors the Testing Project, which tests the migration of IGES to STEP. This is primarily a key issue since IGES Ver. 6.0 is the last version of IGES that will be published. The structure of the IPO is as shown in Figure 2.
Figure 2: IPO Structure

Extracted from presentation "A survey of STEP Project", by David Sanford, Boeing Commercial Airplane Group. October, 1997

How ISO Standards are developed

The ISO/IEC has issued directives in putting together an ISO standard. These directives could be divided into various phases, which are described below:

     

    Phases of developing standards

There are three main phases in the development of International Standards [5].
    Phase 1
The industry sector expresses a need for a standard. This need is communicated to a national member body. The member body proposes this as a New Work item to the ISO. If the need is formally recognized and agreed upon by the ISO community, then definition of the technical scope of the standard is started. Working groups comprising of technical experts from countries interested in the matter work on the definition.
     

    Phase 2

An agreement on the technical aspects to be covered in the standard is reached. Countries negotiate the detailed specifications within the standard. This is called the consensus-building phase.
     

    Phase 3

This involves the formal approval of resulting draft International standard (the acceptance criteria stipulates approval by two-thirds of the ISO members that have participated actively in the standards development process and approval of 75% of all the members that vote). The agreed text is published as an ISO International standard.
     

    Sequence of the Project stages in the ISO Standards development process

The three primary phases are actually broken down into following main project stages
     

    Proposal Stage

At this stage the proposal for a new working item is submitted to the ISO. The approval is required by majority of the P - Members (Refer Section 5.1.2 of this paper). It is also stipulated that 5 countries actively commit to work on a pilot project toward the related field.
    Preparatory Stage
A group of experts is set up by the TC/SC to work out the technical aspects of the future standard. The document generated by the committee is the Working Draft. Successive working drafts may be generated till the technical aspects of the solution to the problem are agreed upon. The draft is then submitted to the WG's parent body for consensus building
    Committee Stage
The first Committee Draft (CD) results from this stage. It is distributed for comments and may be voted on by P-Members, if required. Consensus must be reached on the technical content. Once consensus has been attained, the text is finalized for submission as a Draft International Standard (DIS).
    Enquiry Stage
The DIS is distributed to the members for comments to be returned within a time frame of five months. The resulting document after approvals (ballot) is the Final Draft International Standard (FDIS). If the approval criteria are not met, then the draft is returned back to the originating TC/SC for modifications.
    Approval Stage
The final draft International Standard (FDIS) is circulated to all ISO member bodies by the ISO Central Secretariat for a final Yes/No vote within a period of two months. The text is approved as an International Standard under certain approval criteria. This stage is when the standard formally given ISO standard status.
     

    Publication Stage

The International Standard (IS) is ready to be published after the minor editorial corrections are made. The final text is sent to the ISO Central Secretariat which publishes the International Standard.

The concerned TC/SCs must review all the international standards every five years. Decisions to confirm, revise or withdraw the existing standard are made by the TC/SC.

Industrial Automation Standards

The technical committee is responsible for developing the standard once the technical content of the future standard is finalized. The technical committee TC 184 has four sub-committees, which are responsible for their individual set of standards. We shall explore the work of TC 184 and focus on the suite of standards coming off TC 184/ SC4, commonly known as ‘Industrial Automation Standards’.

 

Technical Committee 184 – Industrial Automation Systems and Integration In December of 1983, the ISO initiated Technical Committee 184 on Industrial Automation Systems and Integration. Subcommittee 4 was formed at that time to work on representing and exchanging digital product data [2]   Technical Committee 184/ Subcommittee 4 TC 184 Subcommittee 4 (TC 184/SC 4) develops International Standards dealing with using digital product and manufacturing management data. The scope of the committee is the standardization of information that is shared or exchanged in the area of industrial and manufacturing applications. Three scope areas have been approved for SC4:   Membership There are approximately 400 experts from 28 countries involved in work related to SC4. There are 19 of these countries classified as Participating or P-Members and 9 as Observer or O-Members.

Technical committees working in related fields establish and maintain liaisons. There are 2 categories of liaison. Category A consists of organizations that contribute substantially contribution to the work of the technical committee. Category B comprises organizations that have requested to be kept informed of the work of the technical committee or subcommittee. The table below shows the members and liaisons of SC4.
P - Members
O - Members
Liaisons
Australia Bulgaria AECMA
Bulgaria Czech Republic CAM-I
Brazil Denmark JTCI/SC21/WG3
Canada Finland JTCI/SC24
China Hong Kong PDES, Inc.
France Portugal ProSTEP
Germany Singapore ISO TC10/SC1
Hungary Spain ISO TC172/SC1
Italy Yugoslavia ISO TC8
Japan   ISO TC211
Republic of Korea POSC
Netherlands EPISTLE
Norway UN/ECE
Romania  
Russia
Sweden
Switzerland
United Kingdom
United States

Table 1: SC4 Members and liaisons
 
Organization of the SC4 Initially, a single working group WG1, which took care of all projects, accomplished the complete work of the SC4. To comply with new ISO/IEC (International Electrotechnical Commission) and in response to a request from TC 184, SC4 reorganized into 6 WGs. The work of the SC4 is currently organized into 9 WGs and 3 Advisory groups. The structure of SC4 is as shown in Figure 4.
Figure 3: Structure of SC4
Adapted from "The Organization of SC". SC4 Handbook. ISO TC SC4 N679 1998-01-26
 

The technical work of each WG is divided into logical tasks. A project leader directs tasks. A convenor leads the project and may serve as a project leader. He/She is additionally responsible for coordinating the other project leaders.

SC4 Working Groups Most of the project work relating to the development of SC4 standards is carried out in the working groups. Each of these groups coordinate and manage all the projects in an identified, and develop new work item proposals. The Working Group acts as the communication channel between the project teams and the Secretariat and the Chair. The following section will highlight the various WGs and their role [2]. Scope: Design a set of standards to specify how a library supplier shall describe the library in a way that this library might be integrated automatically (compiled) into any User Part Library [2].

All kinds of libraries have to be based on the same generic library model. To avoid duplication of work inside SC4, it is important that all work about library structures be done within WG2.

Scope: Develop the parts of ISO 10303 that are members of the integrated resources and application protocol (AP) series. WG3 is divided into teams, each of which has one or more projects.

WG3 Teams are responsible for:

Scope: Develop the languages used in parts of ISO 10303. Scope: Develop methods and the standardized data that will be able to express information exchanged inside industrial manufacturing plants, except for product definition data. Scope: Develop resource models and APs using STEP methodologies with the background of EDIF (Electronic Design Interchange Format), IGES (Initial Graphics Exchange Specifications), and SET (Standard d’exchange et transfert). This group works with IEC TC3. Scope: Resolve the technical direction and related technical issues of SC4 to ensure that the results are consistent with the SC4 directive. Their objective is to define and maintain a consistent set of architectures for the standards within SC4. Scope: WG12 handles STEP Integrated Resources. The activities cover revisions of existing resources, extensions to the capabilities of existing resources, and developing of completely new resources. Current activities are preparing of Version 2 of Parts 41 through 44. Part 42, in particular, will be significantly extended. The short-term activities of the STEP Parametrics Group, who are developing methods for representing parametric, constraint-based and feature-based product models, are also based in WG12, although the longer-term activities of this group has led to developing a new STEP-associated standard, ISO 14959. SC4 Advisory Groups The Advisory Groups are not directly responsible for the development of the standard. However, they perform a very important task in the development process. They aid the individual working groups in their work. Scope: Assist the SC4 chairman, convenors, and project leaders with the following tasks: Membership: PPC consists of six members with management experience. P-members countries nominate candidates for the PPC. Scope: Ensure TC184/SC4 documents are of the appropriate quality. "The mission of the Quality Committee is to facilitate the integration of "quality" in a holistic fashion throughout the life-cycle of STEP parts, utilizing and tailoring existing ISO quality standards and definitions where applicable to define and disseminate repeatable, uniform processes that can be used consistently within the STEP community (TC184 SC4) to produce high quality STEP parts".

 

 

Standards within ISO TC184/SC4 There are presently five standards in the ISO TC184/SC 4 suite of standards. This section will describe each of these standards in brief with a focus on the objective of the standard.   ISO 10303: STEP, the STandard for the Exchange of Product Model data. It is an ISO standard, which is projected to develop mechanisms for representing and exchanging a computerized model of a product in a neutral format. The objective is to enable a product representation to be exchanged without any loss of completeness or integrity. This standard is documented in a number of volumes, called Parts, each containing an element of the STEP technology. Individual applications areas are supported through parts called Application Protocols, which specify unique and unambiguous mappings of the application’s information elements to the STEP information resources. Application Protocols constrain using the standardized representations to satisfy only the specific requirements of the application. Another set of STEP Parts contains the interface specifications used to exchange the product data. Finally, one set of STEP parts specifies how implementations of the standard can be tested for conformance to STEP [5]. ISO 13584 – Parts Library (PLIB) A major element of SC4 standards development is aimed at specifying a capability for sharing parts library information. Libraries of information are critical to many applications in design and engineering where the end product includes assembling of components procured from multiple sources. This standard will offer the capability for computer sensible representation and exchange of parts library data. The objective is to provide a mechanism capable of transferring parts library data and archiving the data. PLIB will represent part library information along with the necessary mechanisms and definitions to enable part library data to be exchanged, used, archived, and updated. The exchange is anticipated among different computer systems and environments associated with the complete life cycle of the products where the library part may be used, including product design, manufacture, use, maintenance, and disposal of the part. The standard will be documented in several parts, which together comprise the technology for representing and sharing library information [5]. ISO 14959 - Parametrics The present version of STEP does not fully reflect the capabilities of modern CAD systems, and there is significant industrial need for an enhanced version. There are two main thrust areas of the work of the Parametrics group, which are explained by a set of aims. These are described below:   ISO 15531 - The Industrial Manufacturing Management Data (MANDATE) This project is developing standards for data (other than product data), which is likely to be shared within an industrial manufacturing plant or data to be exchanged between different manufacturing plants. There are presently three project areas that are being worked upon in MANDATE:   ISO 15926 - Integration of life-cycle data for oil and gas production facilities ISO 15926 will facilitate integrating data to support all the activities associated with the lifecycle of oil and gas facilities. To achieve this objective, the data model must record the meaning of the lifecycle information in a single context supporting all the views that process engineers, equipment engineers, operators, maintenance engineers, and other specialists may have of the facility [5].
  1. ISO STEP Standard Development Process
The ISO STEP Standards are constantly being developed. The STEP Architecture involves 'Application Protocols', 'Integrated Resources' etc. This section discusses about the basic steps in putting any ISO STEP Standard together.

 

Some Definitions Before we get down to the actual process of putting together the STEP standards, the following section will define the elements of the STEP architecture . These elements are related to the development process. Application Protocols (AP): The application protocol converts the end –user requirements into specifications of information for data exchange. APs define the scope of information to be exchanged.

 

Application Activity Model (AAM): Industry needs are described by referring to an Application Activity Model. This model created using modeling techniques such as IDEF0, supports analyzing the activities and information flows within the scope of the industry application. Application Reference Model (ARM): A detailed analysis of the requirements of the industrial application results in a detailed specification of the data objects (entities and attributes), and the relationships between them, that support the activities within the scope of the industry application. Application Interpreted Model (AIM): The AIM satisfies the requirements stated in the ARM through selecting and constraining of standard data constructs. This reuse of standard data constructs across a wide range of industry requirement results in a high degree of consistency and integration across models and enables potential reuse of the software code used in interfaces and potential sharing of common data across application domains. Integrated resources (IR): Integrated resources are in fact composed of two classes: Integrated Generic Resources and Integrated Application Resources. These resources are the standard constructs that define discrete usable objects, for example Part 45 – Materials is a generic resource that will allow the possible combination of material types, quantities, properties, and names to be defined in this group. Application Interpreted Constructs (AIC): Within a group of EXPRESS data models, there will exist some commonality in the structure of the data model, hence commonality in the industrial requirements. These common areas are then grouped into what is known as the Application Interpreted Constructs (AIC), which can be thought of as stand-alone modules. Conformance Classes Conformance classes are developed through analyzing of the usage scenarios identified in the initial phase of the developing the AP, and a thorough understanding of the capabilities of the computer applications that are expected to support the Application Protocol. Abstract Test Suites (ATS): The ATS' are developed after a detailed analysis of the requirements in the AIM and the ARM. The ATS is made up of the following:   Steps involved in putting a STEP standard together The various phases in putting together a STEP standard together are described below [3]:   Application Activity Model (AAM) Phase: The Application Activity Model phase involves using the model to gain international buy-in for the AP and to document the industrial need. Also, data that are in and out of scope of the AP are determined by the group of technical experts. Committee Draft for Comment (CDC) Phase: This phase develops and ballots the application reference model, which is the user’s view, and validates the AAM by consensus. Committee Draft (CD) Phase: This phase develops and presents the application-interpreted model (AIM), which is the primary software model for the AP. The initial mapping of AIM entities to the underlying integrated resource models is presented. A successful CD ballot signals that the AP is reaching technical maturity. Draft International Standard (DIS) Phase: This phase documents the technical maturity and stability of the AP. DIS is typically the phase at which software vendors begin to develop commercial products to implement the AP. Final Draft International Standards (FDIS) Phase: This phase is an editorial process only and no technical changes are considered. A successful FDIS Ballot means the AP is ready for registration as a standard. International Standard (IS) Phase This is the final phase that involves registering the AP as a standard and preparing it for publication.
  1. STEP Standards Development in the Future
Development of STEP standards: the current situation The STEP APs are presently difficult and expensive to develop. They are of variable quality. They are difficult to understand and review and possibly ambiguous to implement. They are very time-consuming as regards to the development and implementations. Each of the AP is being presently developed in isolation of the other APs. This has led to a 'stove-pipe ' approach to the development process.

 

 Scope of the Problem There is a distinct gap in the expectations of the end users and implementers of STEP. The end user of say the Automobile AP - AP214 such as 'Ford' would be interested in the Definitions while an implementer such as a software developer would be interested in 'Abstract Test Cases'.

There is a certain amount of ambiguity introduced with the presence of two data models - the ARM and the AIM. It is found that the AP projects spend a considerable amount of time in analysis and modeling of the ARM. Hence the AIM and ARM are two different solutions of the application areas requirements [4].

 

Modularity is the Key   Status of STEP standards at ISO The development of STEP standards is a continuous activity. It is very encouraging that there is support from industry, government, and academia in this development process. Presently, there are 14 parts registered as International standards [12]. The other parts are at various stages of balloting. This section will give us the current status of the STEP standards at the ISO ballot level.
ISO Part Number
Name of Part
Status
Conformance testing methodology framework
Part 32 Requirements of Testing labs and clients FDIS
Integrated-Application Resources
Part 104 Finite Element Analysis DIS
Application Protocols
Part 204 Mechanical Design using Boundary Representation DIS
Part 205 Mechanical Design using Surface Representation DIS
Part 208 Life Cycle Product Change Process CD
Part 209 Composites and Metal Structure Analysis and Related Design DIS
Part 210 Electronic Printed Circuit Assembly: Product Design Data DIS
Part 212 Electronic P C Assembly: Test, Diag. and Remanufacturing DIS
Part 213 Electrotechnical Design and Installation FDIS
Part 214 Core Data for Automotive Mechanical Design Processes DIS
Part 215 Ship Arrangements CD
Part 216 Ship Molded forms DIS
Part 217 Ship Piping DIS
Part 218 Ship Structures DIS
Part 221 Process Plant Functional Data and its Schema Representation Working Draft
Part 222 Design-Manufacturing for Composite Structures Working Draft
Part 223 Exchange of Design and Manufacturing Product Information for cast parts CD
Part 224 Mechanical parts definition for process planning using machining features FDIS
Part 225 Structural Building Elements using Explicit Shape Representation FDIS
Part 226 Ship’s Mechanical Systems CD
Part 227 Plant spatial configuration DIS
Part 228 Building Services: HVAC O ( proposal stage)
Part 229 Forged parts CD
Part 230 Building Structural Frame: Steelwork CD
Part 231 Process Engineering Data DIS
Part 232 Technical data Packaging: Core information and Exchange CD
Application Interpreted Constructs
Part 501.2 Edge-based representation CD (Revision to IS)
Part 502.2 Shell-based representation CD (Revision to IS)
Part 503.2 Geometric bounded 2D wireframe CD (Revision to IS)
Part 504.2 Draughting Annotation CD (Revision to IS)
Part 505.2 Drawing Structure and administration CD (Revision to IS)
Part 506.2 Draughting elements CD (Revision to IS)
Part 507.2 Geometric bounded surface CD (Revision to IS)
Part 508.2 Non-manifold surface CD (Revision to IS)
Part 509.2 Manifold surface CD (Revision to IS)
Part 510.2 Geometric bounded wireframe CD (Revision to IS)
Part 511.2 Topological bounded surface CD (Revision to IS)
Part 512.2 Faceted B-Representation CD (Revision to IS)
Part 513.2 Elementary B-Representation CD (Revision to IS)
Part 514.2 Advanced B-Representation CD (Revision to IS)
Part 515.2 Constructive Solid Geometry CD (Revision to IS)
Part 516.2 Mechanical –Design Context CD (Revision to IS)
Part 517.2 Mechanical –Design Geometric Presentation CD (Revision to IS)
Part 518.2 Mechanical –Design Shaded Presentation CD (Revision to IS)
Table 2: Current status of SC4 Projects [12]
Adapted from "SC4 Project Status, Leaders, and Stages of Standardization" available at http://www.nist.gov/sc4/www/pro_stat.htm. Last updated Last updated 1998-01-22

 

STEP into the future This section may be referred to from "Introduction to STEP" Section 4. Ravat, Jayesh. OSU STEP Series 006, 1998.
  1. Summary
We cannot deny the fact that standards and standardization seem to touch every area of our lives. Standardization helps to make life easier, and definitely increases the reliability and effectiveness of the goods we use. The New World order enforces the golden rule that standardization is the key to global trading.

The international body ISO is the leading organization responsible for the development of standards that remove the so-called "barriers to trade". The process of putting together these standards seems to be a tedious and time-consuming process. However, the benefits are multifold as are explained in the prior sections.

When we enter the arena of Standards relating to the world of product model data many names come to mind, namely IGES, SET, VDA-FS, etc. However, the rapidly evolving standard "STEP" seems to be emerging as the Standard for the future. There may seem to be many "chinks in the armor" as regards to STEP evolving as the "universal language for model data". This, however, hasn't seemed to slow down the process of development of these standards. Industry, Government and academia are actively involved in the dual areas of development and implementation.

In an increasingly competitive global market, survival is the name of the game. As the world gets "smaller" with advances in communication and "trade boundaries" no longer exist, standards such as STEP will determine if organizations and companies will survive to see the next millennium.

STEP has emerged as a 'proactive standard' for the 21st century. This proactive nature is essentially due to the fact that STEP standards are being developed in anticipation of a future need in industry. This is contrary to the fact that other standards are being developed as reactive standards in response to the needs industry. This feature of STEP standard development ensures all concerned parties including industry, academia, and government to actively participate and shape the future of STEP.

Glossary of Terms
AAM Application Activity Model (STEP Architecture)
AECMA The European Association of Aerospace Industries
AIC Application Interpreted Constructs (STEP Architecture)
AIM Application Interpreted Model (STEP Architecture)
ANSI American National Standards Institute
AP Application Protocol (STEP Architecture)
ARM Application Reference Model (STEP Architecture)
ATS Abstract Test Suites (STEP Architecture)
CAD Computer Aided Design
CD Committee Draft
CDC Committee Draft for Comment
DIS Draft International Standard
EDIF Electronic design Interchange Format
EPISTLE European Process Industries STEP Technical Liaison Executive
FDIS Final Draft International Standard
IC Integrated Constructs (STEP Architecture)
IDEF0 ICAM Definition 0
IEC International Electrotechnical Commission
IGES Initial Graphics Exchange Specification (ANSI Standard)
IPO IGES PDES Organization
IR Integrated Resources (STEP Architecture)
IS International Standard
ISA International Federation of the National Standardization Associations
ISO International Organization for Standardization
JTC Joint Technical Committee
MANDATE Manufacturing Management Data (SC4 Standard)
NIST National Institute of Standards and Technology
NWI New Working Item
PDES Product Data Exchange using STEP (SC4 Standard)
P-LIB Parts Library (SC4 Standard)
POSC Petrotechnical Open Software Corporation
PPC Policy and Planning Committee
QC Quality Committee
SET Standard D'Exchange et de Transfert
SOLIS SC4 Online Information Service
STEP Standards for Exchange of Product Model data (SC4 Standard)
TAG Technical Advisory Group
TC Technical Committee
TMB Technical Management Board
UN/ECE United Nations Economic Commission for Europe
UOF Units Of Functionality
US PRO U.S. Product Data Organization
WG Working Group
 
References:

[1] Fowler, J. "STEP for data management exchange and sharing", Technology Appraisals Ltd., 1995.

[2] Technical Committee 184 for Industrial Automation Systems and Integration Subcommittee 4 for industrial data (TC 184/SC4). "SC4 Organization handbook", SC4 Secretariat, 1988-01-26.

[3] Gruttke, William B. "STEP overview presentation", Oklahoma State University, 09-16-1997.

[4] Fowler, William B. "Modular Development of STEP Application Protocols", ISO TC184/SC 4 & WGs, 1997-10-17/24.

[5] Kemmerer, Sharon J. "International Standards Development Process", ISO TC 184/SC4.

[6] Sanford, David. "A survey of the STEP Project", Boeing Commercial Airplane Group, October 1997.

[7] International Organization for Standardization. "Welcome to ISO Online", March 29, 1998. Available: http://www.iso.ch/

[8] SOLIS Administrator. "SC4 On-Line Information Service (SOLIS)", Last updated 1998-03-06. Available: http://www.nist.gov/sc4/

[9] American National Standards Institute. "ANSI Online", Last updated 30 October 1997. Available http://web.ansi.org/default.htm

[10] US PRO Online Document Catalog. "Welcome to the US PRO Home Page" Last Modified 03/26/98 08:56:22. Available: https://uspro.scra.org/

[11] Ravat, Jayesh S., Nazemetz, John W., Warren, Thomas L. "Introduction to STEP" OSU STEP Series 006, 1998.

[12] Nell, Jim G. "STEP on a page" Available http://www.nist.gov/sc5/soap. Last updated March 16, 1998.

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