Object Temporal Constraint Language OCTL

1
Object Temporal Constraint Language (OCTL)

• Temporal OCL Meeting Specification Demands for
  Business Components
• By
• Stefan Conrad and Klaus Turowski

2
Objectives and Needs

• In component based systems, it is necessary to
  specify
• pre-conditions
• post conditions and
• Invariants
• That look like temporal logic formulas.

3
Control levels according to this paper
4
Specifying COTS components

• COTS components appear at all levels
• Interfaces must be specified at all levels
• Many ways to specify
• Algebraic specifications
• Process models
• Temporal Logics
• UMLOCL
• Out of these methods, UMLOCL cannot be used to
  specify what Temporal Logics can specify.

5
The Need for Temporal Logics

• Components may be distributed
• No global clock
• Time order cannot be specified universally
• Need to specify before after behaviors
• Temporal operators allow these
• OTCL allows these.

6
Temporal Spectrum
7
Temporal Operators 1

• Past Tense Temporal Operators
• Sometime-past f
• always-past f
• f always-since-past y
• f always-since-past y

8
Temporal Operators - 2

• Future Tense Temporal Operators
• Sometime f
• always f
• f until y
• f before y
• Extra addition
• initially f

9
Example - 1

• A service Scheduling can only provide a result
  for some period of time. If a service
  RoughPlanning was already executed before for the
  same period.
• The execution of a service PrintInvoice for an
  order requires it has been entered using the
  service AcceptCustomerOrder and that in between
  this order has not been cancelled using
  CancelOrder

10
Example 2

• productPlanningscheduling(pperiod)
• pre somtime_past( RoughPlanning(p) )

11
Example 3

• orderProcessingPrintInvoice(at Order)
• pre somtime_past( AcceptCustomerOrder(at))
• and not( CancelOrder(at) sometimes_since_last
  AcceptCustomerOrder(at) )
• orderProcessingAcceptCustomerOrder(at Order)
• post sometime( PrintInvoice(at) OR
• sometime (CancelOrder(at))