Transient calculations on process algebra derived Markov chains

The process of obtaining transient measures from a Markov chain as implemented in the software, ipclib is described. The software accepts models written in PEPA, Bio-PEPA or as a Petri net. In the case of the process algebras, a rich query specification language particularly well suited for the derivation of passage-time quantiles is provided. Such measurements are obtained from the derived Markov chain through a process known as uniformisation. The authors detail how the process algebra and query specification language allow one to ensure that the passage-time calculation is valid and then the entire process through to the final calculation of the cumulative distribution and probability density functions of the passage in question. The authors also show a more generic transient measure for which the full probability distributions at specific times are required.