Sometimes some elements of the system model are termed as processors and sometimes as resources, depending on how they are used by the model. For example, in a distributed system a computation job may invoke a server on a remote processor.

  • If it is observed that how the response time of this job is affected by the job which is scheduled on its local processor then remote server serve as a
  • Remote server can be modelled as a

There is no fixed rules to guide us in deciding whether to model something as a processor or as a resource, or to guide us in many other modelling choices but it deepens on the design criteria. A good model can give us better insight into the real-time problem that are considered during modelling. A bad model can confuse us and lead to a poor design and implementation. For example, a model transactions that query and update a database as jobs; these jobs execute on a database server so database server acts as the processor. If the database server uses a locking mechanism to ensure data integrity, then a transaction also needs the locks on the data objects it reads or writes in order to proceed. The locks on the data objects available on database server are considered as resources.