Defining Systems for more that 40 years

PSL/PSA - Present


The Project to make PSL/PSA available has several activities ongoing now:

1. Website - this website. A full version of the PSL syntax is available here. It is not  the same as the original printed language summary as there are significant restrictions in HTML over the representation of the braces and brackets used in the original documentation for selection and optionality. فيتامين E The original language documentation will be placed here in an appropriate HTML format.

2. Documentation - the PSL/PSA reference manuals have been re- constructed. Publication can happen when viable. The material will be converted also to a suitable form to place on this website alongside the PSL syntax pages.

3. Archive - an archive of the ISDOS project has been constructed from what has survived.Unfortunately some documents are no longer available. Offers of any archival material are very welcome. An Index of the archive will be posted here from time to time.

4. Symposium - a Symposium will be held when arrangements can be made to do so. Hosting offers are welcome. It is hoped to bring together people who were originally involved in ISDOS, PRISE, or PSL/PSA, along with others who are interested in finding out about PSL/PSA and associated tools. Please let  me know if you would like to participate, write a paper, or be a member of the Symposium Board.

5. Software - work to produce a prototype of a replacement for PSL with the same functionality, but radically different technology is in an advanced stage with the first version working. More effort is needed to determine what kinds of reports people would like, as a replacement for the original PSA part of PSL/PSA.

6. Training - training is available as facility on-site training. Public courses may become available as demand increases. Training that can be delivered includes: PSL/PSA Overview; PSL/PSA User Course; Strategy, Analysis and Design with PSL/PSA; Tailoring PSL/PSA to a System Development Method; Using PSL/PSA to Implement IEEE Software Engineering Standards. skin care


Further activities are planned and will be announced here when appropriate.

Work has now started to rebuild PSL/PSA. It is expected that a new version (v7.0) will be available in 2013. The rebuild of PSL/PSA will use completely new technology rather than being a port of earlier versions. The following table sets out the current view of releases:




New availability of PSL on a contemporary platform.


Implementation of Level 1 form shown in Business Process Analysis


Addition of Level 2 objects and relationships shown in Business Process Analysis book.


Modified PSL based on feedback from users and new sponsors.

Prior to a release of a full PSL/PSA ported to new technology, there will be a PSL-lite. This is intended to be an open-source simplified version of PSL/PSA. When it is released as open source  اونيلا will depend on securing some sponsorship or some modest stream of income.


© Geoffrey Darnton 1992-2018