  The use of object oriented techniques and methodologies for the design of
real-time control systems appear to be necessary in order to deal with the
increasing complexity of such systems. Recently many object-oriented methods
have been used for the modeling and design of real-time control systems. We
believe that an approach that integrates the advancements in both object
modeling and design methods, and real-time scheduling theory is the key to
successful use of object oriented technology for real-time software. However,
past approaches to integrate the two either restrict the object models, or do
not allow sophisticated schedulability analysis techniques. In this paper we
show how schedulability analysis can be integrated with object-oriented design;
we develop the schedulability and feasibility analysis method for the external
messages that may suffer release jitter due to being dispatched by a tick
driven scheduler in real-time control system, and we also develop the
scheduliability method for sporadic activities, where message arrive
sporadically then execute periodically for some bounded time. This method can
be used to cope with timing constraints in complex real-time control systems.
