Agenda
- Issues re: Device and Device Metric resources
- Device - parent vs. HasPart
- Device - other
- DeviceMetric - cleanup and Device fallout
Attendees
Stefan Karl, Koichiro Matsumoto, Elliot Silver, Ken Fuchs, Tom Kowalczyk, john Donnelly, John Garguilo, John Rhoads (notes)
Meeting Notes
- Device: Device.parent or Device.hasPart
- Main argument has been that since hasPart is preferred in DeviceDefinition for good reasons (reuse, enabling putting in a quantity of reused parts), it should be adopted in Device for consistency
- Question: is consistency really such a strong argument when the reasons for hasPart in DeviceDefinition (description of a kind) seem less pertinent for Device (active data for a particular device.
- Device.parent prevents a device from having multiple parents, which is an error in the modeling adopted so far.
- Quantities of a part are not wanted since each part in the containment hierarchy is a distinct instance having a unique identity and independently varying values of attributes.
- Contained device instances may "need to know" when they are in use (presence or absence of a parent value) and where attached (the parent value). With hasPart, these data items are elsewhere and must be searched for.
- These items could be countered by producing a use case where hasPart is clearly superior in a hierarchy of instances