Resource allocation behaviour

Hi all,

I know I went a bit quiet with the resource levelling work, but I  
hope to send patches to this list within the next couple of days  
which will introduce an option on a planner project to choose whether  
or not to switch on resource allocation checking, and if on, choose  
which of any number of algorithms to use for the project.

At the moment I only have the simplest 'do not allow resource  
overloading' algorithm in place, but there are plenty of ideas on the  
bugzilla for others which I intend to implement.

For today, however, I would like to ask for advice/discussion. The  
option I mention above needs adding to the mrp-project data schema,  
and I would also like to extend the mrp-resource data schema with a  
'maximum allocatable units' field definable on each resource.

First, is there a review process for changing the planner data schema?

Secondly, are there any gotchas or lessons learned that anyone can  
think of which I should be aware of regarding making such changes?

- I know there is the regular XML and database support/data  
translation to take into account for saving data which has been input  
under the new schema, and that I will have to update and release tag  
the sql database structure dump which is bundled with the source

- I know will have to impose a default for the new data fields when  
loading planner files which have been saved under older schemas  
(following the principle of least surprise, 100 for resource usage  
and 'ignore overloading' for the project allocation behaviour field)

Have I missed any other formats or conversions? Has anyone else added  
things to the schema and been tripped up by anything I should be  
aware of? My work so far has been on a completely different section  
of the code, I haven't really been near the project load and save  
routines yet, so any hints will be gratefully appreciated!

Thanks in advance for any comments,
lee