A small model of a location tracking system based on
active badges was made by Stephen Gilmore, Jane Hillston and
Graham Clark. The paper Specifying
performance measures for PEPA appeared in the
proceedings of Fifth International AMAST Workshop on Real-Time
and Probabilistic Systems.
Two medium-sized PEPA examples are here. They model a
PC-LAN as described in lecture notes from the University of Edinburgh
lecture course `Modelling and Simulation''. The lecture notes explain
how certain performance measures are calculated.
Jane Hillston, Marina Ribaudo and Stephen Gilmore made a
model of the TOMP machine protocol. This model can be scaled very
simply by varying the number of copies of number of copies of the
processes which are competing for memory access. The description of
the model and timings for runs of the PEPA Workbench on a 500MHz
Pentium III with 128Kb of memory appear in the paper An efficient algorithm for aggregating PEPA
models which is to appear in IEEE Transactions on Software
Engineering. Here is a collection of models of the TOMP machine
with increasing numbers of copies of components.
Jeremy Bradley and Stephen Gilmore made a model of a web server
which can be scaled by varying the number of servers, number
of readers, number of writers or buffer size. This can be
used to generate systems with very large state spaces. The
model is studied in the paper ``Derivation of Passage-time
Densities in PEPA models using ipc:
The Imperial PEPA Compiler".
The mobile agent system is a very simple PEPA net which models a
mobile software agent which moves from one host to another
harvesting information which it dumps to a central analysis
point. The example is discussed in the paper
PEPA nets: a structured performance
modelling formalism which appeared in the proceedings
of Tools 2002.
The concrete syntax for PEPA supported by the Möbius
modelling platform differs slightly from the syntax supported by other PEPA tools. Below is the tiny example in the Möbius syntax.