Anatoly Levenchuk (ailev) wrote,
Anatoly Levenchuk
ailev

Курс "Введение в системную инженерию" в МФТИ, 2013г. -- 6

Сегодня провёл шестое из восьми аудиторных занятий курса "Введение в системную инженерию" для пятикурсников МФТИ (заметки к первым пяти занятиям -- http://ailev.livejournal.com/1068803.html, http://ailev.livejournal.com/1070301.html, http://ailev.livejournal.com/1071842.html, http://ailev.livejournal.com/1072233.html, http://ailev.livejournal.com/1072854.html).

Занятие получилось практически лекционным (если не считать двадцати минут на тестирование -- я попросил студентов по памяти нарисовать диаграммы, которые подолгу висели на доске не предыдущих занятиях: диаграмму альф Essence, V-диаграмму и какие-нибудь сочинённые ими диаграммки описаний системы по мотивам ISO 42010).

Было три предмета обсуждения: связь теории и жизни, разбирательство связи науки и инженерии как изобретения методов описаний/теорий/viewpoints и изобретением описаний/моделей/models из их групп/views, а также демонстрация разных групп описаний одного и того же куска системноинженерной жизни с использованием разных методов описаний (например, обсуждение вопроса о том, чем отличаются работы/work и технология/way-of-working в Essence -- ведь работы поминаются в них обоих! И вообще, как собрать воедино те описания, которые получены при использовании самых разных стандартов, поминаемых в нашем курсе).

То есть это занятие было посвящено вопросам применения теоретического знания на практике, а также вопросам склейки разных знаний.

Вот что было нарисовано на одной из досок:


Обсуждавшийся отрывок из ISO 11354-1 Advanced automation technologies and their applications — Requirements for establishing manufacturing enterprise process interoperability — Part 1: Framework for enterprise interoperability
В пункте 5.4.1
There are three approaches to achieve enterprise interoperability:
-- integrated,
-- unified,
-- and federated.
These three approaches were first identified in ISO 14258.

5.4.2 Integrated approach
In the integrated approach a common form shall be used to represent the exchanged entities. This common form shall be sufficiently expressive to capture those details that affect interoperability of the items to be exchanged, rather than the process or system as a whole. The common form is not necessarily an International Standard, but needs to be agreed by participating enterprises in order to elaborate these entities and build systems accordingly.

EXAMPLE Examples of developing interoperability using an integrated approach are ISO 10303, ISO 19440 and OASIS/UNCEFACT ebXML

The integrated approach assures consistency and coherence of the interoperating subsystems by focusing on the components that need to interact. These components are then designed and implemented using a common form (or standard) so that interoperability is seen as a designed-in quality. Interoperation between these various components is therefore obtained a priori without any interfacing effort. Subsystems that are integrated in this way have distinct and individual structure, behaviour, or boundaries, but their combined behaviour is perceived to be as one entity and is achi eved by collaboration and coordination through the use of the common form.

5.4.3 Unified approach
In the unified approach, a common meta-model, which is applicable for the participating entities and used as a common reference to map existing models’ syntax and semantics, shall be identified and detailed. This meta-model provides at least a reference vocabulary, but could be a complete ontology. Such a meta-model is not an executable entity. Instead, it s hall provide a means for semantic equivalence to enable mapping between entities. Using this meta-model, a translation between the constituent entities is then possible. However, that translation might involve the loss of some informati on because the participating entities can have different extensions or instantiations of the same meta-model.

NOTE 1 The unified approach is particularly suitable when developing interoperability for collaborative or networked
enterprises. To be interoperable with networked business partners, a new company maps its own model or system to the neutral meta-model without the necessity to make changes on its own model or system. This approach has an advantage over the integrated approach because of the reduced efforts, time and cost in implementation. It is also suitable for a situation where a large company needs to interoperate with SMEs. Normally an SME works with more than one large company; to interoperate with different companies, the unified approach can be a suitable solution in that it facilitates coordination without requiring conformance to potentially conflicting processes or environments.

NOTE 2 In the re-engineering situation, syntactic alignment can be achieved through a unified approach that uses a mapping function to create missing elements of the exchange items, but semantic alignment between partners can be very difficult. Therefore, re-engineering is more applicable to developing intra-enterprise interoperability.

5.4.4 Federated approach
In the federated approach, there is no sufficiently capable common form or meta-model to guide the interaction between enterprises that need to interoperate . The lack of capability is often related to different terminologies or methodologies that need to be resolved by business entity interaction. While there can be a common understanding between the business entities, in the federated approach, no business entity imposes their own models, languages and methods of work.

To establish interoperability, parties shall accommodate and adjust their operations. Interoperation can be supported by providing a priori information about the capabilities of the entities to be involved in the exchange or by employing agents to discover the needed information. Support for the a priori case can be provided by establishing entity capability profile s that hold syntactic and semantic information on both entity inputs and outputs. Interoperability can be established by mapping corresponding input and output information of the entities and identifying inconsistencies. Any remaining inconsistencies shall be resolved by manual interventions.

This approach is more suitable for peer-to-peer situations, where each enterprise has resources for negotiation and compromise. The approach is particularly adapted to virtual enterprises, where diverse companies combine their resources and knowledge to manufacture a product for a limited duration.

NOTE Using the federated approach to develop enterprise interoperability is most challenging. A main research area is development of a mapping factory that can generate on-demand customized “anybody-anywhere-anytime” mapping agents among existing systems. It is worth noting that a specific support for the federated approach is seen in entity profiles, which identify particular entity characteristics and properties relevant for interoperation (e.g. ISO 15745 and ISO 16100).
К следующему занятию студенты должны закончить знакомство с материалом курса, и мы будем тренироваться в использовании полученных ими в данном курсе viewpoints для описания/моделирования их проектов и систем -- и далее использованию этих описаний для улучшений. Таких занятий будет два, а потом останется только выставить оценки.
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