Tools Overview Contact Us Publications Case Studies Manual Home

APHzip is a collection of tools to generate, manipulate, and compress acyclic phase-type representations. The toolsuite can generate simple exponential or Erlang distributions, and by using the disabling operator (cox) can even generate the whole acyclic phase-type representations. To manipulate acyclic phase-type representations, APHzip provides three stochastic operations: convolution, maximum, and minimum. APHzip also implements an algorithm that almost surely reduces any given acyclic phase-type representation to its minimal representation.

This webpage is an interface to APHzip, which is implemented as a web service with this WSDL definition.


An Android app, designed to provide a very easy-to-use interface to APHzip web service, is availabe at Google Play or directly downloadable from here. The app works for Android 4.0 or later. This Youtube video gives a demonstration on how to use the Android app.

The Tool

As an example, copy the following expression, and paste it to the provided form below (more examples can be found here):

Output: Cox in disabling operators form (cox)
Cox in state-transition form (tra)
Depending on the expression you've entered, the computation may take some time to complete and a timeout may occur. In this case, we recommend the user to provide an email address, to which the result will be sent.


Reza Pulungan initiated the APHzip project as a part of his Ph.D thesis under the guidance of Professor Holger Hermanns. He is the main developer of the tool, and Holger Hermanns is a key contributor.

* This work has been supported by the DFG as part of the SFB/TR 14 "Automatic Verification and Analysis of Complex Systems" (AVACS), by the DFG/NWO Bilateral Research Programme ROCKS, and by the European Union Seventh Framework Programme under grant agreement no. 295261 (MEALS). Part of this work was done while Reza Pulungan was a guest of the Saarbrücken Graduate School of Computer Science funded by the German "Exzellenzinitiative des Bundes und der Länder".

Contact and Support

For questions, comments and support requests regarding APHzip, as well as for question regarding the APHzip homepage, please contact "pulungan [at] ugm [dot] ac [dot] id".

Valid XHTML 1.1 Valid CSS! Powered by PHP