Model Authorities and Model Exchange Jay Britton Principal Architect

> Title of presentation - Date - References33 Model Exchange Business Goal  Neighboring parties in an interconnect exchange models.  Each party is the “modeling authority” only for its own territory.  Each party will use other parties’ internal models to create their external model.  To accomplish this, 1. Each party exports its internal model to its neighbors and keeps it up to date. 2. Each party imports each neighbor’s model and uses it to develop and update its external model.  Proposed Goal: an external model can be updated within an hour of a change to a neighbor’s internal.

> Title of presentation - Date - References44 CIM Exchange (full, partial, incremental) Initial CIM Model Exchange Concept A Internal Model A’s model of B b a Proprietary / Home grown Extract / Merge Tools Proprietary / Home grown Extract / Merge Tools CIM import / export System A Local Vendor Model System A Import Model B’s Model of A B Internal Model System B Local Vendor Model System B Import Model CIM import / export System A EMS System B EMS

> Title of presentation - Date - References55 Making CIM Exchange a Complete Process  MRIDs as permanent unique object identifiers.  Decide who assigns identifiers to each object.  Name registry manages naming differences.  Model exchange uses consistent identifiers.  Specify the modeling territories precisely within the model.  Include security against changes submitted by unauthorized parties.  Report updates with CIM incremental updates.  If problems arise, it is easy to identify the source.  Mark equivalents in the model.  Import process can easily recognize whether an update requires a new reduction.  On-line systems receive and test updates incrementally.  If problems arise, it is easy to identify the source

> Title of presentation - Date - References66 Central Concept: Model Authority Sets (MAS)  Notation:  Nodes represent individual CIM objects.  Branches represent relations between objects.  Two MAS types:  Regional (single authority)  Boundary (bipartisan authority / single caretaker)  Rules:  Every CIM object is in one and only one MAS.  Each MAS controls object MRIDs in its territory.  No object in a regional set relates directly to any object in another regional set.

> Title of presentation - Date - References77 A little more detailed look at a boundary example.

> Title of presentation - Date - References88 A UCTE boundary example.

> Title of presentation - Date - References99 System A EMS System B EMS Use Case: Peer-to-Peer Full Model Exchange Proprietary Model A A Region B Region boundary A Region B Region boundary A Region (reduced) B Region (reduced) Proprietary Model B CIM import CIM Modeler b a

> Title of presentation - Date - References10 System A Local Vendor System B Local Vendor Use Case: A to B Incremental Update Proprietary Model A A Region B Region boundary A Region B Region boundary A Region (reduced) B Region (reduced) Proprietary Model B CIM MAS CIM delta CIM Modeler aa CIM delta If the change can be processed against the reduced region, then it can be transferred directly to the CIM import for system B.

> Title of presentation - Date - References11 CIM Upper Tier Modeling CIM Region Modeling System A Local Vendor Use Case: Hierarchical Exchange System B Local Vendor A Region B Region boundary Proprietary Model A Proprietary Model B CIM import A Region B Region boundary A Region B Region boundary A Region (reduced) B Region (reduced) b a x

> Title of presentation - Date - References12 Why is this a good thing?  Generality  MAS delineate all objects, not just the physical connection boundaries.  Establishing authority and responsibility…  Basis for efficient, repeatable processes.  Clarifies responsibility for naming and MRIDs for all objects.  Processing efficiency for model exchange:  Merging regions is a simple union of objects.  Extraction is a simple transfer of objects without modification.  Replace simply extracts and discards before merging.  Maximum XML file size can be limited to maximum largest MAS size, rather than whole interconnect.  Checking that a change comes from the correct source.  As a regional MA submitting a change: You can make any change you want to your regional set without fear that it would disturb a relationship from another region. Your changes can easily be validated because they must be referentially complete without any other regional set. If your change cannot comply with the above condition, it tells you immediately that you need to arbitrate a change in a boundary set.  As the receiver checking the right to make a change: It must be referentially complete against the source’s region plus its boundaries.