[Erp5-dev] projects using Simulation

[Sebastien Robin]

Hi,

For all projects using the "simulation" world of ERP5, some special 
attention will be needed. You can find a description of what 
"simulation" is here :

http://www.erp5.com/documentation/developer/design/developer-Simulation/view

Before 2010, we started to have some weakness in our simulation design 
when we wanted to handle complex cases of business. We were using 
simulation since several years and we cumulated several ideas for 
improving it. Therefore we improved a lot the design of all the 
simulation code. In order to keep freedom in the new design, we had no 
other choice to break the compatibility with previous version of 
simulation and data.

Up to now, it is still possible to use old simulation design and data 
thanks to ERP5Legacy product and to erp5_simulation_legacy business 
template. We still have unit test checking that old simulation is still 
working.

But around May 2012, we will stop maintenance of ERP5Legacy product and 
erp5_simulation_legacy business template since all our projects will use 
new simulation at that time and we can not keep oldest code forever.

We already had several projects who were able to successfully move from 
old simulation to new one with some migration scripts. Here how we 
managed to do it :
1 - first write test checking that the project can runs well with latest 
simulation (erp5_simulation bt).
2 - check how different are simulation trees between old and new simulation.
3 - write migration scripts to transform old trees to new trees

We are going to commit this November in erp5 repository 
(http://git.erp5.org/gitweb/erp5.git) an example of migration for 
Tasks/Tasks Reports. Then it is possible to reuse same algorithm to 
migrate other tress (with some adaptation depending on your project).

If anyone needs the legacy code for more time and is ready to help for 
maintenance, that's also fine even though it is much nicer to move to 
new simulation.

Regards.

   Sébastien.