A method of scheduling a request for a plurality of Web services can
include providing service activation rules. Each service activation rule
can specify a trigger condition and a state condition for causing a
watcher to invoke a particular Web service. The method also can include
receiving an event indicating a change in a common memory, wherein each
event specifies trigger information, comparing the trigger conditions of
the service activation rules with the trigger information of the event,
adding the service activation rules that match the event to a trigger
list, and comparing the state conditions of service activation rules in
the trigger list with a state of the common memory. The service
activation rules of the trigger list that match the state of the common
memory can be selected thereby causing the invocation of at least one
watcher and corresponding Web service.