Common use of Design Space Exploration Clause in Contracts

Design Space Exploration. To define a design space to explore, initialisation attributes in CoHLA are very useful. As Situations and ClassInitialisa- tions affect the initialisation values for federate instances, these can also be used to specify a design space. CoHLA has been extended by allowing the user to specify lists of different initialisation values for federate instances or attributes. As there are three methods to assign initialisation values, we also consider three different types of lists that can be used to define a design space. • Lists of initialisation values are lists that specify specific values for initialisation attributes of a specific federate instance. For every initialisation attribute for every ▇▇▇▇▇- ation instance, such list may be given in a DSE definition. 1 Set bottomSlider.startPosition : "0.15", " 0.05", "-0.05", "-0.14" Listing 5. Example of a list of initialisation values. • Lists of ClassInitialisations are lists that specify ClassIn- itialisations that should be applied to a specific federate instance. A DSE definition may contain one list for every federate instance in the federation. 5▇▇▇▇▇://▇▇▇▇▇.▇▇▇/ 6▇▇▇▇▇://▇▇▇.▇▇▇▇▇▇.▇▇▇/ element in the list with all other design space elements defined. Table I shows a design space for a hypothetical system. The system consists of two federates, each having two attributes. All but one attributes have three possible design parameters. When using independent exploration behaviour, there are 27 possible system configurations: (x, a, q, u), (x, a, q, v) Independent behaviour can only be used when leaving out Attribute C from the design space, which results in three possible system configurations: (x, a, u), (y, b, v) and (z, c, w). 1 DSE strokeStartPositions { 2 SweepMode Independent 3 Set bottomSlider.Position_realInitial : "0.15", "0.05", "-0.05", "-0.14" 4 Set supervisoryController.initSpeed : "1.0", " 1.5", "2.0", "2.5", "3.0" 5 } Listing 8. Design Space definition for the SliderSetup. Listing 8 displays a design space definition for the Slider- Setup. The design space specifies two lists, each containing initialisation attribute values. The initialisation attributes are used to specify a starting position for the bottom slider and an initialisation speed for the supervisory controller. As the SweepMode is set to Independent, the design space has a size of 20 (4 5) possible configurations. From this design space definition, a DSE configuration file is generated by the code generator. These configuration files can be used to easily perform a different DSE as described in Section III-A. The simulation results will be written to log files.