  Timing aspects in formalisms with explicit resources and parallelism are
investigated, and it is presented a formal link between timed membrane systems
and timed Petri nets with localities. For both formalisms, timing does not
increase the expressive power; however both timed membrane systems and timed
Petri nets are more flexible in describing molecular phenomena where time is a
critical resource. We establish a link between timed membrane systems and timed
Petri nets with localities, and prove an operational correspondence between
them.
