OMG System Modeling Language Avatar
  1. OMG Specification

OMG System Modeling Language — Open Issues

  • Acronym: SysML
  • Issues Count: 7
  • Description: Issues not resolved
Open Closed All
Issues not resolved

Issues Descriptions

Binding to multiplicity in parametrics

  • Key: SYSML17-38
  • Legacy Issue Number: 14998
  • Status: open  
  • Source: INCOSE ( Sanford Friedenthal)
  • Summary:

    In parametrics, one cannot currently bind a constraint parameter in a constraint expression to a multiplity. For example, one may need to include the number of tires in the constraint expression that constraints braking force. However, if the model includes a Vehicle, composed of Tire with multiplicity 4, one must be able to access the number of tires (i.e. the multiplity) in the expression.

  • Reported: SysML 1.1 — Thu, 21 Jan 2010 05:00 GMT
  • Updated: Mon, 17 Jun 2019 14:00 GMT

Ability for a binding connector to be typed

  • Key: SYSML17-40
  • Legacy Issue Number: 15079
  • Status: open  
  • Source: INCOSE ( Sanford Friedenthal)
  • Summary:

    A binding connector used in parametrics should allow for decomposition via association blocks in a similar way that other connectors support decomposition. The specification currently includes a constraint on Block that precludes this as follows: “The number of ends of a connector owned by a block must be exactly two. (In SysML, a binding connector is not typed by an association, so this constraint is not implied entirely by the preceding constraint.)”

  • Reported: SysML 1.1 — Sat, 20 Feb 2010 05:00 GMT
  • Updated: Sun, 13 Jan 2019 15:32 GMT

Proposal to have a stereotype for reference nested property

  • Key: SYSML17-36
  • Legacy Issue Number: 14055
  • Status: open  
  • Source: International Business Machines ( Eldad Palachi)
  • Summary:

    When one needs to reference a value of a specific property of part in a composition hierarchy in order to bind it to a constraint parameter, one uses the dot notation shown in section 8.3.1.2. (Example: a box labeled myCar.myEngine.currentTemp in a parametric diagram). When such a box is binded to a constraint parameter a nested connector end may be used to reference this property in the context of the composition hierarchy. However this poses a serious implementation issue for tools since until the box is binded it has no real model element behind it, also if one copies this box or the diagram to another hierarchy in the model then the tool has to complicated analysis. We propose to have a stereotype for reference nested property similar to nested connector end in which the path in the composition hirerchy is specified (i.e. propertyPath: Property [1..*] (ordered) - like in section 8.3.2.6). This will make it easier for tools to implement backed by the standard meta-model.

  • Reported: SysML 1.1 — Sun, 5 Jul 2009 04:00 GMT
  • Updated: Sun, 13 Jan 2019 15:32 GMT

Table 16.2 (top of pg. 146): Trace Dependency concrete syntax diagram incorrect

  • Key: SYSML17-35
  • Legacy Issue Number: 13942
  • Status: open  
  • Source: NASA ( Jeff Estefan)
  • Summary:

    Table 16.2 (top of pg. 146): Trace Dependency concrete syntax diagram incorrect. Replace <<requirement>> Client with Named Element (no stereotype). Figure 16.1 (top of pg. 148): Recommend adding Refine stereotype (as specialization of Trace stereotype); otherwise note that it comes directly from UML metaclass rather than as a UML extension. Recommend reordering specializations of trace in alphabetical order on UML class diagram (e.g., Copy, DeriveReq, [Refine], Satisfy, Verify). Section 16.3.2: Should reintroduce Refine relationship description and contraints, even though a UML metaclass and not an extension. It is an important relationship with respect to requirements. Perhaps introduce prior to Sect 16.3. Section 16.3.2.3 (middle of pg. 150): Change cardinality of /derived: Requirement attribute from [0..1] to [*]. Also, add right bracket to cardinality of /master: Requirement attribute. Currently shows as [0..1 with not closing right bracket.

  • Reported: SysML 1.1 — Fri, 29 May 2009 04:00 GMT
  • Updated: Sun, 13 Jan 2019 15:32 GMT

Allocations should not generate dependencies

  • Key: SYSML17-34
  • Legacy Issue Number: 13840
  • Status: open  
  • Source: Airbus Group ( Yves Bernard)
  • Summary:

    Allocations should not generate dependencies The Allocate stereotype extends the Abstraction UML meta-class, which is a Dependency. It is in contradiction with the following description (cf. p133: "This concept requires independent models if “function” (behavior) and “form” (structure)") If we refere to EIA-632 the logical solution that will be allocated to the physical solution only depends from upstream requirements. In some cases, one may have some (upstream) requirements to use a given implementation platform, but this cannot be considered generic and anyway the dependendcy is still on the requirement not directly on the platform. A logical solution makes abstraction of the implementation to focus on issues strictly related to the missions of the system. Then, by definition a logical solution is semantically dependent from the need and not from the implementation. In most times, several logical solutions are possible. Their are more or less effective against each of their requirements, that's why the design work includes tradeoff activities. Saying that a given logical solution is not convenient to be implemented on a given platform doesn't mean that it's not a logical solution to the need. More, the current stereotype implementation biases the impact analysis. The objective of this analysis is to parse the model and to report what model elements should be reviewed (i.e. are potentially impacted) in case of modification of a given model element to preserve the model integrity and consistency. If the platform is modified, what has first to be checked is whether or not the modified elements of the platform can still play the role they have been assigned by the allocation (with the required QoS, etc...). If the answer is "yes", then nothing to do. If the answer is "no", then they are several potential choices: a) if possible modify the allocations only, b) select another logical solution (i.e. modify it) and define the new allocations, b) select another platform and define the new allocations. This is matter of tradeoff. The only point that has always to be checked is the allocations. Then the only "thing" that actually depends on the "from" and "to" sides of an allocation is the allocation itself.

  • Reported: SysML 1.1 — Fri, 27 Mar 2009 04:00 GMT
  • Updated: Sun, 13 Jan 2019 15:32 GMT

AllocateActivityPartition and UML 2 semantics

  • Key: SYSML17-33
  • Legacy Issue Number: 13342
  • Status: open  
  • Source: NIST ( Conrad Bock)
  • Summary:

    In Allocations, AllocateActivityPartition, Constraints, the second paragraph says the AllocateActivityPartition stereotype does nopt preserve the semantics of of UML 2 ActivityPartition, and that partitions with AllocateActivityPartition do not have responsibility for invoking the actions in them. I think there is no conflict with UML 2 semantics, because UML 2 ActivityPartition only requires performing the actions to be the responsibility of the element represented by the partiion, not the invoking of the action. This seems compatible with allocation.

  • Reported: SysML 1.1 — Mon, 26 Jan 2009 05:00 GMT
  • Updated: Sun, 13 Jan 2019 15:32 GMT

Representation of nested object nodes in activity diagrams

  • Key: SYSML17-30
  • Legacy Issue Number: 13197
  • Status: open  
  • Source: INCOSE ( Sanford Friedenthal)
  • Summary:

    Issue: Representation of nested object nodes in activity diagrams. Discussion: It is desirable to be able to represnt nesting of object nodes on activity diagrams to reflect one or more levels of nested properties of the classifier that types the object node. For example, if water is shown as an object node, and it is desired to refer to the temperature of water, then it should be possible to reflect this property on the activity diagram using the notations that are used on ibd's. In particular, one may want to use either a nested rectangle to represent the property, or the dot notation. Proposed update. In the diagram extensions for activity diagrams in Section 11.3.1.4, add a clarifying statement that nested properties of the classifier that types an object node can be represented on activity diagrams either using the nested rectangle notation or the dot notation similar to the use of nesting on ibd's and parametric diagrams.

  • Reported: SysML 1.1 — Wed, 31 Dec 2008 05:00 GMT
  • Updated: Sun, 13 Jan 2019 15:32 GMT