Vassilis Mertsiotakis

Learn More
This paper introduces stochastic process algebras as an approach for the structured design and analysis of both the functional behavior and performance characteristics of parallel and distributed systems. This is achieved by integrating stochastic modelling and analysis into process algebras like CCS or LOTOS. We demonstrate how notions of equivalent(More)
Stochastic Process Algebras have been proposed as compositional speciication formalisms for performance models. In this paper, we describe a tool which aims at re-alising all beneecial aspects of compositional performance modelling, the TIPPtool. It incorporates methods for compositional speciication as well as solution, based on(More)
1 There are many ways to incorporate a notion of time into process algebras in order to integrate functional design and performance analysis. One major research strand, stochastic process algebras, concentrates on the annotation of actions with exponentially distributed random variables. This paper presents a tool for the functional analysis and performance(More)
Many modern computer and communication systems result in large, complex performance models. The compositional approach ooered by stochastic process algebra constructs a model from submodels which are smaller and more easily understood. This gives the model a clear component-based structure. In this paper we present cases when this structure may be used to(More)
When implementing parallel programs for parallel computer systems the performance scalability of these programs should be tested and analyzed on different computer configurations and problem sizes. Since a complete scalability analysis is too time consuming and is limited to only existing systems, extensions of modeling approaches can be considered for(More)
In this paper we present an extension of the process algebra modelling methodology which allows qualitative and quantitative modelling to be integrated. This extension, to form stochastic process algebras (SPA), has been recently demonstrated to have many interesting features. Such languages serve two purposes as a formal description language for computer(More)
We present an approach for the efficient approximation of the throughput of decision free processes, a class of sto-chastic process algebra models. Stochastic process algebras are modeling formalisms which are based on communicating sequential processes, in contrast to stochastic Petri nets which focus on causality and concurrency. The algorithm we are(More)
Constructing large Generalized Stochastic Petri Nets (GSPN) by hierarchical composition of smaller components is a promising way to cope with the complexity of the design process for models of real hardware and software systems. The composition of nets is inspired by process algebraic operators. A solid theoretical framework of such operators relies on(More)
Testing the performance scalability of parallel programs can be a time consuming task, involving many performance runs for different computer configurations, processor numbers , and problem sizes. Ideally, scalability issues would be addressed during parallel program design, but tools are not presently available that allow program developers to study the(More)