1.1 Important
Because changes made to the method definitions also implicitly
change the models based on the methods, changing components of a method that is
in use can have far-reaching and possibly undesired effects. We have done our
best to ensure that no change is possible which would damage old models.
However, there are changes that might be desirable in one situation and
positively detrimental in another. You should be especially wary of making
changes to the predefined methods that were delivered with the MetaEdit+ Method
Workbench package, because then you might not be able to use our new versions of
the methods. If you want to modify the predefined methods, you could subclass
the appropriate components and modify the subclasses.
Because method development also affects existing system
descriptions, changing the underlying metamodel on the fly, the method
development tools provide very powerful functions for CASE customisation.
Therefore you should be aware that:
 | Modifications
to types affect all the models that have been made, or will be made with all the
techniques, where the type is
used. |
 | The
modifications will affect model data on the next access to it. In a multi-user
situation, changes to types, like changes to instances, only affect other users
after you have committed and they have started a new
transaction. |
So before any big modification
efforts, remember to backup your database! This is particularly important
in changes involving adding, moving or removing properties from a type, or
changing the data type of a property type.
If you are unable to make modifications to methods, check
that you are running the Method Workbench version of MetaEdit+, and that your
system administrator has included you in the set of users allowed to metamodel.
If you are running the multi-user version of MetaEdit+, your system
administrator may also have set restrictions about simultaneous metamodellers
and modellers, e.g. metamodelling is only allowed when nobody else is logged in
(the default), or only one metamodeller (and any number of modellers) is allowed
at a time.
Before trying out any of these tools, read these chapters
carefully!