Add extension to language to support synchronization Example : Communicating Sequential Processing (CSP) , Restricted Blocking Advantage : Lead to implementation Disadvantage : Hard to visualize and difficult to verify.
| Type | Advantage | Disadvantage |
| OCPN (Object Composition Petri Net) | Capture all the necessary temporal relations. | Lack capabilities to specify communication requirements and control function for distributed composition of multimedia documents |
| G-Net | Allow specifications of communication primitives and type of connections that can be established among communication sites. | Over simplified and does not facilitate generation of multimedia documents |
Figure 11-5 shows an OCPN with QOP parameters. 
The means to manipulate or control the presentation of temporal specification Example : reduce or increase the speed of multimedia presentation.