UML Futures

1
UML Futures

• Steve Cook, Microsoft
• steve.cook_at_microsoft.com

2
Problems with UML2

• Unintended inheritance
• Ambiguity
• Interoperability failure
• Conflict of goals
• Velocity of issue resolution process

3
Unintended Inheritance

• A few examples
• Behavior.IsActive
• Meaningless?
• Behavior.superClass
• Can Behaviors inherit? Whats the notation?
  Semantics?
• Activity.IsReentrant vs Activity.IsSingleExecuti
  on
• Looks to mean the same?
• Property.upperValue Duration
• Clearly meaningless
• UseCase associations
• Multiplicity (8854)? Can UseCases compose? Have
  Association Classes?
• N-ary dependencies in component wiring
• Component wiring is clearly binary, non-duplicate
  links
• Importing a Package into a Transition
• ...

4
Ambiguity

• Absence of a well-defined mapping between
  diagrams and metamodel instances, e.g.
• General consequences of unintended inheritance
• Component diagrams dependency-based wiring vs
  connector-based wiring
• Association end navigability
• Can you put a context-less Behavior on a
  class/package diagram?
• ...
• Invalid/missing OCL

5
Interoperability failures

• UML ambiguity
• XMI version profligacy
• XMI option profligacy
• No compliance / interop suite

6
Conflict of Goals

• Is UML a reusable/extensible syntax or a language
  with semantics? It cannot be both!
• This is vaguely recognised through semantic
  variation points there are no formal semantics
  for vanilla UML.
• We now have Semantics of a Foundational Subset
  for Executable UML Models, which does a proper
  job of giving executable semantics for a subset
  of UML.
• It would be appropriate to recognise this
  explicitly, and instead have a well-defined,
  interoperable Abstract Syntax spec that
  corresponds with diagrams, with separate
  semantics.

7
RTF Process Velocity

• The file http//www.omg.org/issues/uml2-rtf.open.h
  tml contains 577 open issues including 20 marked
  Critical.
• In that file the phrase Due to lack of time, the
  RTF/FTF agrees that the following are problems
  that need fixing, but decided to defer their
  resolution to a future RTF working on this
  specification 172 times and Resolution
  deferred for the next RTF 17 times.
• The stalest open issue is dated 2000 and 42 are
  dated 2003.
• There are 578 closed issues recorded, including 9
  marked Critical.
• This means at best a date of gt2013 before the
  existing issues are resolved at current speed,
  assuming no more issues are raised.

8
Summary

• UML2 has fundamental issues that will not be
  fixed in a timely fashion through the RTF process
• I propose a roadmap working group to report back
  within one OMG meeting cycle
• Does UML need an RFI?
• Does UML need a new RFP?
• Scope?
• Timescale?

9
Invalid OCL
context Componentprovided derive let
implementedInterfaces self.implementation-gtcolle
ct(implimpl.contract) and let realizedInterfaces
RealizedInterfaces(self) and let
realizingClassifierInterfaces
RealizedInterfaces(self.realizingClassifier) and
let typesOfRequiredPorts self.ownedPort.provided
in (((implementedInterfaces-gtunion(realizedInter
faces)-gtunion(realizingClassifierInterfaces))-gt
union(typesOfRequiredPorts))-gtasSet()