The core of MOSEL consists of a set of language constructs to
specify the possible states and state changes of
a system. Additional syntax is dedicated to the description of the
conditions under which transitions are allowed or prohibited.
In order to model the temporal behaviour of the system
adequately, possible state changes can either occur immediately
or after a delay which is chosen according to a continuous
probability distribution. Not only exponentially distributed
delays are possible, the delay can
also be distributed according to a Pareto- , Weibull-,
Normal- and some more kinds of distributions. If a transition
will always occur after a fixed amount of time
(e.g. timeouts in protocols) a deterministic transition can be
specified in the MOSEL model in oder to reflect this kind of system
behaviour appropriately. Moreover, transitions which occur during
a time interval with known start- and endpoints and equal probability
for each timepoint in the interval can be modelled as a
uniformly distributed transition in MOSEL.
In contrast to many specification languages of existing performance
and reliability modeling and analysis tools, which often tend to
be too verbose, most MOSEL specifications are compact
but anyhow easy to understand. MOSEL contains many keywords
and control structures which are also used in general purpose
programming languages. This creates a familiar ambiance for many
Moreover, MOSEL provides means by which many interesting
performance or reliability measures and the
graphical presentation of them can be specified
straightforward. Reward-like result specifications are
possible. It is especially easy to analyse a model with many
sets of different system parameters.
The benefit of MOSEL - especially for the practitioner from the
industry - lies in its modeling environment: A MOSEL
model can automatically be translated into various tool-specific
system descriptions and then are analyzed by the appropriate
tools. This exempts the modeller from the time-consuming task
of learning different modeling languages.
The MOSEL constructs and model structure are described here.
The MOSEL modeling environment is described here.