Emilija Kamceva, Filip Tancev
LESIJ NO. XVIII, VOL. 1/2011
MODELING AND SIMULATION OF QUEUE WAITING THROUGH
THE CONCEPT OF PETRI NETS
Emilija KAMCEVA ∗
Filip TANCEV ∗∗
Petri Nets-PN are a graphical formalism which is gaining popularity in recent years as a
tool in Matlab for the representation of complex logical interactions among physical components
or activities in a system. This notes are devoted to introduce the formalism of Petri nets with
particular emphasis on the application of the methodology in the area of th e performance and
reliability modelling and analysis of systems. A technique is presented whereby queueing network
models and generalized stochastic Petri nets are combined in such a way as to exploit the best
features of both modeling techniques. The resulting hierarchical modeling approach is useful in
the solution of complex models of system behavior.
Keywords: Petri nets, modeling and simulation, toolbox PNTool 2.3, queue.
Petri Nets offer profound mathematical background originating namely from linear algebra
and graph theory. Various Petri Net tools offer convenient graphical environment and sometimes
they provide complex simulation and analysis of various high level Petri Net classes.
Petri Net (PN) is mathematical and graphical modeling tool well suited for describing and
analyzing discrete events systems (DES). PNs allow to model and visualize systems, which
contain concurrence, resource sharing or synchronization. These possibilities allow them to be
used for various applications in areas including computer systems, communication protocols,
flexible manufacturing systems and software verification.
Within the mentioned context, the initiative of developing instruments for simulation,
analysis and design of PNs under MATLAB brought remarkable benefits for training and research
because Control Engineering people are familiar with the exploitation of Graphical User
Interfaces (GUIs)1 based on this popular software. Although a recent list of the programs
developed for PNs includes many resources (Mortensen, 2003) running under different operating
systems, our initiative was successful due to the large preference shown for MATLAB.
It is worth separately mentioning that the overall design and implementation philosophy
that sustains the PN Toolbox, as well as the integration with MATLAB, allow further
∗ Faculty of Information and Communication Technology, FON University, Skopje, Macedonia
∗∗ Faculty of Information and Communication Technology, FON University, Skopje, Macedonia
1 The GUI gives the possibility to draw PNs in a natural fashion and allows a straightforward access to various
commands starting adequate procedures for exploiting the PN models.