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51-885: The objective of the international standard is to provide a mechanism that is capable of describing product data throughout the life cycle of a product , independent from any particular system. The nature of this description makes it suitable not only for neutral file exchange, but also as a basis for implementing and sharing product databases and archiving. STEP can be typically used to exchange data between CAD , computer-aided manufacturing , computer-aided engineering , product data management / enterprise data modeling and other CAx systems. STEP addresses product data from mechanical and electrical design, geometric dimensioning and tolerancing , analysis and manufacturing, as well as additional information specific to various industries such as automotive , aerospace , building construction , ship , oil and gas , process plants and others. STEP

102-520: A bit within their industries. Joseph Whitworth 's screw thread measurements were adopted as the first (unofficial) national standard by companies around the country in 1841 . It came to be known as the British Standard Whitworth , and was widely adopted in other countries. By the end of the 19th century differences in standards between companies were making trade increasingly difficult and strained. The Engineering Standards Committee

153-410: A book written in 2019 by Nicholas Rich and Tegwen Malik gives a very comprehensive overview of the history of standards, how ISO standards are drafted along with key ISO standards such as ISO 9001 and ISO 14001. A paper has been published explaining the differences between international standards and private standards . One of the most well established international standardization organizations

204-417: A box conveys the specific role of the interface. The controls enter the top of the box. The inputs, the data or objects acted upon by the operation, enter the box from the left. The outputs of the operation leave the right-hand side of the box. Mechanism arrows that provide supporting means for performing the function join (point up to) the bottom of the box. The IDEF0 process starts with the identification of

255-536: A commission to oversee the process. By 1906 , his work was complete and he drew up a permanent constitution for the first international standards organization, the International Electrotechnical Commission (IEC). The body held its first meeting that year in London , with representatives from 14 countries. In honour of his contribution to electrical standardisation, Lord Kelvin was elected as

306-413: A compound acronym ("Icam DEFinition for Function Modeling", where ICAM is an acronym for "Integrated Computer Aided Manufacturing"), is a function modeling methodology for describing manufacturing functions, which offers a functional modeling language for the analysis, development, reengineering and integration of information systems , business processes or software engineering analysis. IDEF0

357-446: A definition of a graphical modeling language ( syntax and semantics ) and a description of a comprehensive methodology for developing models. The US Air Force commissioned the SADT developers "to develop a function model method for analyzing and communicating the functional perspective of a system. IDEF0 should assist in organizing system analysis and promote effective communication between

408-429: A diagram by boxes) and the data and objects that inter-relate those functions (represented by arrows). The IDEF0 model displayed here on the left is based on a simple syntax . Each activity is described by a verb-based label placed in a box. Inputs are shown as arrows entering the left side of the activity box while output are shown as exiting arrows on the right side of the box. Controls are displayed as arrows entering

459-535: A large user base, doing some well established thing that between them is mutually incompatible. Establishing international standards is one way of preventing or overcoming this problem. To support this, the World Trade Organization (WTO) Technical Barriers to Trade (TBT) Committee published the "Six Principles" guiding members in the development of international standards. The implementation of standards in industry and commerce became highly important with

510-526: A particular kind of product or data exchange scenario. To provide a better understanding of the scope, information requirements and usage scenarios an informative application activity model (AAM) is added to every AP, using IDEF0 . STEP is primarily defining data models using the EXPRESS modeling language. Application data according to a given data model can be exchanged either by a STEP-File , STEP-XML or via shared database access using SDAI . Every AP defines

561-520: A proposal to form a new global standards body. In October 1946 , ISA and UNSCC delegates from 25 countries met in London and agreed to join forces to create the International Organization for Standardization (ISO); the organization officially began operations in February 1947 . Global standards are also referred to as industry or private standards , which are designed and developed with

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612-696: A semantic data modeling technique. By the 1990s, IDEF0 and IDEF1X techniques are widely used in the government, industrial and commercial sectors, supporting modeling efforts for a wide range of enterprises and application domains. In 1991 the National Institute of Standards and Technology (NIST) received support from the U.S. Department of Defense, Office of Corporate Information Management (DoD/CIM), to develop one or more Federal Information Processing Standard (FIPS) for modeling techniques. The techniques selected were IDEF0 for function modeling and IDEF1X for information modeling . These FIPS documents are based on

663-483: A successor of IGES , SET and VDA-FS . The initial plan was that "STEP shall be based on one single, complete, implementation-independent Product Information Model, which shall be the Master Record of the integrated topical and application information models". But because of the complexity, the standard had to be broken up into smaller parts that can be developed, balloted and approved separately. In 1994/95 ISO published

714-526: A top data models to be used for data exchange, called the Application Interpreted Model (AIM) or in the case of a modular AP called Module Interpreted Models (MIM). These interpreted models are constructed by choosing generic objects defined in lower level data models (4x, 5x, 1xx, 5xx) and adding specializations needed for the particular application domain of the AP. The common generic data models are

765-439: A work item (NWI) for a new standard. The original intent of STEP was to publish one integrated data-model for all life cycle aspects. But due to the complexity, different groups of developers and different speed in the development processes, the splitting into several APs was needed. But this splitting made it difficult to ensure that APs are interoperable in overlapping areas. Main areas of harmonization are: For complex areas it

816-484: Is clear that more than one APs are needed to cover all major aspects: STEP programs International standard An international standard is a technical standard developed by one or more international standards organizations . International standards are available for consideration and use worldwide. The most prominent such organization is the International Organization for Standardization (ISO). Other prominent international standards organizations including

867-568: Is closely related with PLIB (ISO 13584, IEC 61360). The basis for STEP was the Product Data Exchange Specification (PDES) , which was initiated during the mid-1980's and was submitted to ISO in 1988. The Product Data Exchange Specification (PDES) was a data definition effort intended to improve interoperability between manufacturing companies, and thereby improve productivity. The evolution of STEP can be divided into four release phases. The development of STEP started in 1984 as

918-461: Is developed and maintained by the ISO technical committee TC 184, Automation systems and integration , sub-committee SC 4, Industrial data . Like other ISO and IEC standards STEP is copyright by ISO and is not freely available. However, the 10303 EXPRESS schemas are freely available, as are the recommended practices for implementers. Other standards developed and maintained by ISO TC 184/SC 4 are: STEP

969-464: Is divided into many parts, grouped into In total STEP consists of several hundred parts and every year new parts are added or new revisions of older parts are released. This makes STEP the biggest standard within ISO. Each part has its own scope and introduction. The APs are the top parts. They cover a particular application and industry domain and hence are most relevant for users of STEP. Every AP defines one or several Conformance Classes, suitable for

1020-572: Is part of the IDEF family of modeling languages in the field of software engineering , and is built on the functional modeling language Structured Analysis and Design Technique (SADT). The IDEF0 Functional Modeling method is designed to model the decisions, actions, and activities of an organization or system. It was derived from the established graphic modeling language Structured Analysis and Design Technique (SADT) developed by Douglas T. Ross and SofTech, Inc. In its original form, IDEF0 includes both

1071-793: Is shown in Figure 4. In Dec 1993 the National Institute of Standards and Technology announcing the standard for Integration Definition for Function Modeling (IDEF0) in the category Software Standard, Modeling Techniques. This publication announces the adoption of the IDEF0 as a Federal Information Processing Standard (FIPS). This standard was based on the Air Force Wright Aeronautical Laboratories Integrated Computer-Aided Manufacturing (ICAM) Architecture from June 1981. On September 2, 2008,

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1122-710: Is the International Telecommunication Union (ITU), a specialized agency of the United Nations which was founded on 17 May 1865 as the International Telegraph Union. The ITU was initially focused on the standardization of telegraph signals, and later evolved to include telephony , radio and satellite communications, and other information and communication technology . By the mid to late 19th century , efforts were being made to standardize electrical measurement. An important figure

1173-508: Is very similar to the ISO 15926-2 model, whereas AP 221 follows the STEP architecture and ISO 15926-2 has a different architecture. They both use ISO-15926-4 as their common reference data library or dictionary of standard instances. A further development of both standards resulted in Gellish English as general product modeling language that is application domain independent and that is proposed as

1224-488: Is well-tested and proven through many years of use by government and private industry. It can be generated by a variety of computer graphics tools. Numerous commercial products specifically support development and analysis of IDEF0 diagrams and models. An associated technique, Integration Definition for Information Modeling (IDEF1x), is used to supplement IDEF0 for data-intensive systems. The IDEF0 standard, Federal Information Processing Standards Publication 183 (FIPS 183), and

1275-470: The International Telecommunication Union (ITU) and the International Electrotechnical Commission (IEC). Together, these three organizations have formed the World Standards Cooperation alliance. International standards can be applied directly or adapted to meet local conditions. When adopted, they lead to the creation of national standards that are either equivalent to or largely align with

1326-491: The initial release of STEP as international standards (IS) with the parts 1, 11, 21, 31, 41, 42, 43, 44, 46, 101, AP 201 and AP 203. Today AP 203 Configuration controlled 3D design is still one of the most important parts of STEP and supported by many CAD systems for import and export. In the second phase the capabilities of STEP were widely extended, primarily for the design of products in the aerospace, automotive, electrical, electronic, and other industries. This phase ended in

1377-574: The AIM was also used for the ARM. Over time these ARM models got very detailed till to the point that some implementations preferred to use the ARM instead of the formally required AIM/MIM. Today a few APs have ARM based exchange formats standardized outside of ISO TC184/SC4: There is a bigger overlap between APs because they often need to refer to the same kind of products, product structures, geometry and more. And because APs are developed by different groups of people it

1428-439: The AIM, called MIM. Modules are built on each other, resulting in an (almost) directed graph with the AP and conformance class modules at the very top. The modular APs are: The modular editions of AP 209 and 210 are explicit extensions of AP 242. The STEP APs can be roughly grouped into the three main areas design, manufacturing and life cycle support. Design APs: Manufacturing APs: Life cycle support APs: The AP 221 model

1479-451: The IDEF manuals published by the U.S. Air Force in the early 1980s. Sometime later, IEEE created the IDEF0 standard, and ISO adopted and published it as IEEE/ISO/IEC 31320-1. IDEF0 may be used to model a wide variety of automated and non-automated systems. For new systems, it may be used first to define the requirements and specify the functions, and then to design an implementation that meets

1530-636: The IDEF1x standard (FIPS 184) are maintained by the National Institute of Standards and Technology (NIST). FIPS PUB 183 "Integration Definition for Function Modeling (IDEF0)," was withdrawn as a Federal Standard (in favor of OPEN Specifications and Standards) September 2, 2008, as cited in "The Federal Register", Volume 73, page 51276 (73FR/51276). During the 1970s, the U.S. Air Force Program for Integrated Computer Aided Manufacturing (ICAM) sought to increase manufacturing productivity through systematic application of computer technology. The ICAM program identified

1581-570: The analyst and the customer through simplified graphical devices". Where the Functional flow block diagram is used to show the functional flow of a product , IDEF0 is used to show data flow , system control, and the functional flow of lifecycle processes. IDEF0 is capable of graphically representing a wide variety of business, manufacturing and other types of enterprise operations to any level of detail. It provides rigorous and precise description, and promotes consistency of usage and interpretation. It

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1632-503: The basis for interoperability between APs for different kinds of industries and life cycle stages. In APs with several Conformance Classes the top data model is divided into subsets, one for each Conformance Class. The requirements of a conformant STEP application are: Originally every APs was required to have a companion Abstract test suite (ATS) (e.g. ATS 303 for AP 203), providing Test Purposes , Verdict Criteria and Abstract Test Cases together with example STEP-Files. But because

1683-499: The body's first President. The International Federation of the National Standardizing Associations (ISA) was founded in 1926 with a broader remit to enhance international cooperation for all technical standards and specifications. The body was suspended in 1942 during World War II . After the war, ISA was approached by the recently formed United Nations Standards Coordinating Committee (UNSCC) with

1734-500: The development of an ATS was very expensive and inefficient this requirement was dropped and replaced by the requirements to have an informal validation report and recommended practices how to use it. Today the recommended practices are a primary source for those going to implement STEP. The Application Reference Models (ARM) is the mediator between the AAM and the AIM/MIM. Originally its purpose

1785-494: The development of the STEP modular architecture (400 and 1000 series). This activity was primarily driven by new APs covering additional life-cycle phases such as early requirement analysis (AP 233) and maintenance and repair (AP 239), and also new industrial areas (AP 221, AP 236). New editions of the previous monolithic APs on a modular basis have been developed (AP 203, AP 209, AP 210). The publication of these new editions coincided with

1836-404: The entire world in mind. Unlike international standards, these standards are not developed in international organizations or standards setting organizations (SSO) which follow a consensus process. Instead, these standards are developed by private sector entities, like NGOs and for-profit organizations, often without transparency, openness, or consensus considerations. IDEF0 IDEF0 ,

1887-787: The following previous APs in an upward compatible way: AP 242 was created by merging the following two Application protocols: In addition AP 242 edition 1 contains extensions and significant updates for: Two APs had been modified to be directly based on AP 242, and thus became supersets of it: AP242 edition 2, published in April 2020, extends edition 1 domain by the description of Electrical Wire Harnesses and introduces an extension of STEP modelisation and implementation methods based on SysML and system engineering with an optimized XML implementation method. This new edition contains also enhancements on 3D Dimensioning and Tolerancing, and Composite Design. New functionalities are also introduced like: STEP

1938-432: The international standards in technical content, though they may have: (i) editorial variations, such as differences in appearance, the use of symbols, measurement units, or the choice of a point over a comma as the decimal marker, and (ii) variations arising from conflicts with government regulations or industry-specific requirements, which may be influenced by factors such as climate, geography, technology, infrastructure, or

1989-574: The lack of efficiency in this system and began to consider proposals for an international standard for electric engineering. In 1904 , Crompton represented Britain at the Louisiana Purchase Exposition in St. Louis as part of a delegation by the Institute of Electrical Engineers . He presented a paper on standardisation, which was so well received that he was asked to look into the formation of

2040-523: The need for better analysis and communication techniques for people involved in improving manufacturing productivity. As a result, in 1981 the ICAM program developed a series of techniques known as the IDEF (ICAM Definition) techniques which included the following: In 1983, the U.S. Air Force Integrated Information Support System program enhanced the IDEF1 information modeling technique to form IDEF1X (IDEF1 Extended),

2091-524: The onset of the Industrial Revolution and the need for high-precision machine tools and interchangeable parts . Henry Maudslay developed the first industrially practical screw-cutting lathe in 1800, which allowed for the standardisation of screw thread sizes for the first time. Maudslay's work, as well as the contributions of other engineers, accomplished a modest amount of industry standardization ; some companies' in-house standards spread

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2142-416: The prime function to be decomposed. This function is identified on a “Top Level Context Diagram,” that defines the scope of the particular IDEF0 analysis. An example of a Top Level Context Diagram for an information system management process is shown in Figure 3. From this diagram lower-level diagrams are generated. An example of a derived diagram, called a “child” in IDEF0 terminology, for a life cycle function

2193-497: The release in 2010 of the new ISO product SMRL , the STEP Module and Resource Library, that contains all STEP resource parts and application modules on a single CD. The SMRL will be revised frequently and is available at a much lower cost than purchasing all the parts separately. In December 2014, ISO published the first edition of a new major Application Protocol, AP 242 Managed model based 3d engineering , that combined and replaced

2244-413: The requirements and performs the functions. For existing systems, IDEF0 can be used to analyze the functions the system performs and to record the mechanisms (means) by which these are done. The result of applying IDEF0 to a system is a model that consists of a hierarchical series of diagrams, text, and glossary cross-referenced to each other. The two primary modeling components are functions (represented on

2295-399: The safety standards deemed necessary by the relevant authorities. International standards are one way to overcome technical barriers in international commerce caused by differences among technical regulations and standards developed independently and separately by each nation, national standards organization, or business. Technical barriers arise when different groups come together, each with

2346-408: The top of the box and mechanisms are displayed as arrows entering from the bottom of the box. Inputs, Controls, Outputs, and Mechanisms (ICOM) are all referred to as concepts. IDEF0 is a model that consists of a hierarchical series of diagrams, text, and glossary cross referenced to each other. The two primary modeling components are: As shown by Figure 3 the position at which the arrow attaches to

2397-619: The year 2002 with the second major release, including the STEP parts AP 202, AP 209, AP 210, AP 212, AP 214, AP 224, AP 225, AP 227, AP 232. Basic harmonization between the APs especially in the geometric areas was achieved by introducing the Application Interpreted Constructs (AIC, 500 series). A major problem with the monolithic APs of the first and second releases is that they are too big, have too much overlap with each other, and are not sufficiently harmonized. These deficits led to

2448-512: Was R. E. B. Crompton , who became concerned by the large range of different standards and systems used by electrical engineering companies and scientists in the early 20th century . Many companies had entered the market in the 1890s and all chose their own settings for voltage , frequency , current and even the symbols used on circuit diagrams. Adjacent buildings would have totally incompatible electrical systems simply because they had been fitted out by different companies. Crompton could see

2499-403: Was always an issue to ensure interoperability between APs on a higher level. The Application Interpreted Constructs (AIC) solved this problem for common specializations of generic concepts, primarily in the geometric area. To address the problem of harmonizing the ARM models and their mapping to the AIM the STEP modules were introduced. They contain a piece of the ARM, the mapping and a piece of

2550-726: Was established in London in 1901 as the world's first national standards body. After the First World War , similar national bodies were established in other countries. The Deutsches Institut für Normung was set up in Germany in 1917 , followed by its counterparts, the American National Standard Institute and the French Commission Permanente de Standardisation , both in 1918 . There are not many books that cover standards in general, but

2601-406: Was only to document high level application objects and the basic relations between them. IDEF1X diagrams documented the AP of early APs in an informal way. The ARM objects, their attributes and relations are mapped to the AIM so that it is possible to implement an AP. As APs got more and more complex formal methods were needed to document the ARM and so EXPRESS which was originally only developed for

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