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Comments on doing a CIM Project. jay.britton@areva-td.com. CIM Design Center. A rule I learned about applying technology: Understand the design center of the technology. Use extreme caution if trying to apply the technology outside its design center. CIM Design Center
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Comments on doing a CIM Project jay.britton@areva-td.com
CIM Design Center • A rule I learned about applying technology: • Understand the design center of the technology. • Use extreme caution if trying to apply the technology outside its design center. • CIM Design Center • CIM standards aim to simplify integration of components and expand options for supply of components by standardizing information exchanges. • Reduce complexity with clear consistent semantic modeling across the enterprise. • Data sources: achieve a clear picture of data mastership in the enterprise. • Data consumers: make ‘data of record’ available on demand to qualified users. • CIM employs a canonical data model (CDM) strategy for standardizing interfaces in the power system operations and planning domain.
CIM Design Center (cont’d) • The CIM CDM is partitioned into sub-domains by IEC WGs. • These groups work hard to maintain a unified semantic model over the whole domain. • The interfaces defined under CIM are organized into profiles. • A profile specifies the information structure of exchanged information by creating contextual semantic models. • Contextual semantic models are a subset of the CIM CDM. i.e. They inherit their structure from the CIM CDM. • Contextual semantic models could contain information not modeled in the CIM CDM. • This is not current CIM practice for standard interfaces. • There is typically a family of related interfaces defined within a profile. • Products implement support for profiles. • Testing occurs against profiles. • CIM compliance is defined against profiles. • There is no such thing as just ‘CIM compliant’. You have to specify the profile. • Do not expect CIM to make sense outside its design center. • If its not needed in a CIM interface, don’t expect it to be in the model. • Don’t expect that CIM is a good database schema. • Don’t expect CIM to make a good class design for your application.
Overview of CIM Standards Methodology Canonical Data Model
CIM Evolution • CIM is designed to achieve consistent, high quality models across a large domain. • This mission requires that CIM is able to change as new interfaces are added. • Typically it is not possible to preserve semantic quality if changes are restricted to additions. • At the global CDM level, change is embraced as long as it makes a significant contribution to semantic quality. • Stability may be addressed as appropriate at profile levels. • Profiles are where the investment is made. • Contextual model is derived from a version of the CIM CDM. • Subsequent changes to CIM do not require that the contextual model be updated. • At the profile level, the participants in the profile can determine how often to update their profile. • About Versioning… • CIM CDM and contextual models will change. • Contextual models do not need to be updated simply because CIM CDM changes.
How to Cope with Versions • An enterprise integration strategy based on CDM(s) is a good idea. • Multiple CDMs are likely, but keep the number small. • Extensions will be necessary when starting from core standards like CIM. • An enterprise application of CIM will typically consist of information exchanges based on more than one version of the CDM. • Critical decision: CIM CDM may be adopted just as a starting point, or the plan will be to keep current as CIM and contextual models evolve. • Use of evolving Smart Grid standards will probably demand staying with CIM. • A successful evolution strategy requires discipline in implementation to reduce the cost of subsequent updates. • There will be lots of reasons raised as to why CIM should just be used as a starting point. • To enable evolution… • Implementation must minimize direct connection between exchanged data and internal data. • i.e. Do not hardwire CIM to application internals – it makes changes too costly.
Transformations are Key Compatible version exchange. • Transform issues • Clarity • Simple, low cost implementation • Maintainability • Performance! Incompatible version exchange.
You may think that CIM is complex. • From the standpoint of one information exchange implementation, it is. • If you compare life cycle of 100 exchanges, each implemented in CIM, against other alternatives, CIM is much simpler. • CIM isn’t the easiest way to do anything – but it is the easiest way to do everything.