MARTE12_ — Annotation of Criticalities of NFP values

Mix-criticality systems have the need to host for a concrete magnitude (e.g. WCET) different values, each corresponding to a different level of criticality.

The simplest way to have this available in MARTE is by following the same approach used for the source qualifier, this is by including an attribute of the type NPF_Integer (or even integer), called "CriticalityLevel" in NFP_Common_Type.
This way the currently available versions of the MARTE profile do not need to be updated; only the parsers of VSL values commited to support mixed critical systems would need to be modified to parse the criticality attribute on VSL values if present.

This would need a change in Figure D.5 and the text describing the NFP_Common_Type on page 504, by adding the attribute: criticalityLevel: NFP_Integer [*] Value(s) that defines the level(s) of criticality at which the NFP annotation is valid.

In a separate issue we express also the need to annotate criticalities for NFP_Constraints, but for the sake of easying the resolution of the two issues please consider in this issue only the annotation of criticalities to NFP values.

Criticality is a designation of the level of assurance against failure needed for a system component. A mixed criticality system is one that has two or more distinct levels (consider for example safety critical, mission critical and non-critical). Reviewing the standards in the field (IEC 61508, DO-178B, DO-254 and ISO 26262 standards) they propose to use up to five levels. Then, in general an integer value (better if represented with NFP_Integer) is sufficient to annotate the criticality level for a value or a constraint.

Deferred

Defer the handling of this issue to MARTE 2.0