Performance Evaluation Process Algebra

Acknowledgements and thanks

The PEPA Eclipse Plug-in and the associated Bio-PEPA Eclipse Plug-in have been implemented by Allan Clark, Adam Duguid, Michael Smith, Mirco Tribastone, and Chris Williams at the University of Edinburgh.


Software to analyse and simulate PEPA models is available from this site as a free download. The PEPA software is implemented entirely in Java and depends upon the Eclipse integrated development environment. The PEPA software also includes support for modelling in Bio-PEPA, a related language with features which make it suitable for modelling biological processes.

If you do not have Java installed already then you should install the Java SE Development Kit from

Compatible Eclipse versions (Updated: August 2021)

Recent updates to the Eclipse platform mean that the PEPA Eclipse Plug-in cannot be installed on the latest versions of Eclipse since 2021. In order to install PEPA currently it is necessary to download an older version of Eclipse and to install PEPA in that version. We recommend installing Eclipse version 2020-09 (4.17.0), available from

We hope that we will be able to solve this problem in the future to allow PEPA to run on the latest version of Eclipse, but at present it is not known when this will be done.

Installing PEPA (v25)

Version v25 of the PEPA Eclipse Plugin is the most recent release of the PEPA Eclipse Plug-in, released in November 2014. It is available from

Use Help>Install New Software… and add to your list of available software locations. We have called this site "PEPA" in the screenshot below.

Installing PEPA screenshot

Add all the PEPA software as illustrated in the screenshot below.

Adding software screenshot

Follow the prompts to complete the installation of the software.

Installation screenshot

Accept the license agreement when prompted to do so.

License agreement screenshot

The PEPA software is not cryptographically signed, but is safe to install.

Confirm imstall screenshot

Finally, restart Eclipse.

Restart Eclipse

You may need to upgrade other parts of your Eclipse installation to complete this. These include the GEF, Zest and Draw2D packages. If so, Eclipse will prompt you to do this.

Create a new project in Eclipse with File>New>Project… and Choose General>Project. You can call this project whatever you wish, but we called our project PEPA.

Create a new file in this project using File>New>Other… and choose General>File. Be sure to name your file with the extension .pepa. Do not use .txt or any other file extension.

You are now ready to start modelling with PEPA.

If you are planning to model with Bio-PEPA instead then follow the instructions above but name your file with the extension .biopepa instead.

New features in this release

Version v25 of the PEPA Eclipse Plug-in features a new capacity planning extension for optimising systems using search to find the best number of component repliations to meet performance targets at the lowest possible cost.

Problems and troubleshooting

When you install PEPA via Eclipse you are installing new software on your machine. On some platforms you may need to temporarily turn off your virus checking software (e.g. Norton) to allow PEPA to be installed, or otherwise give Eclipse permission to install software.

Contact addresses: Jane Hillston and Stephen Gilmore, {jeh,stg}
    Laboratory for Foundations of Computer Science, The University of Edinburgh.
Last modified: Mon 2 Aug 11:04:40 BST 2021