Specialized Administration > Tailoring Business Objects > Object Initialization Rules Administration > Understanding Object Initialization Rules > Changing Numbering Schemes
  
Changing Numbering Schemes
Numbering schemes control how numbers are generated for parts, baselines, documents, CAD documents, dynamic documents, and change objects. The out-of-the-box numbering scheme for parts, documents, CAD documents, and change objects are simple sequences that have been loaded into the Windchill database. Each starts at 1 and increments by 1.
Out of the box, there is no separate numbering scheme set for dynamic documents. Dynamic documents use the same numbering scheme as CAD documents unless you add an object initialization rule that sets the numbering scheme for the EPM Document subtype associated with dynamic documents. For an example of setting autonumbering for dynamic documents, see Dynamic Document Numbering.
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Ensure that the numbering scheme that you want used is in place before allowing users to create parts, baselines, documents, CAD documents, dynamic documents, and change objects. Changing the numbering scheme after objects are created can cause problems if the new scheme attempts to reproduce a number that has already been used.
You can view and update the rules that are being used from the Object Initialization Rules table using the Object Initialization Rules Administration utility. For details on assessing the Object Initialization Rules Administration utility, see Accessing the Object Initialization Rules Administration Utility.
Removing the XML element that defines a numbering scheme from a rule in a specific context causes the numbering scheme established in the parent context to be used. If you remove the elements defining the numbering scheme in all contexts in the hierarchy, then manual numbering occurs.
Additionally if a parent context has autonumbering turned on, you can turn off autonumbering in a specific application context or organization context by including only an empty constraints list for the number attribute in the context for which you want autonumbering turned off. For example, the out-of-the-box rules for WTPart set in the site context autogenerates the number of a part. To turn off the autonumbering in a specific application context or organization context, replace any existing XML elements used for constraining the number attribute in that context with the following or add a new rule for WTPart including the following elements if none exists:
<AttrConstraint id="number"
algorithm="com.ptc.core.rule.server.impl.GatherAttributeConstraints">
</AttrConstraint>
Using the out-of-the-box rules for WTPart and WTDocument, the number of parts and documents that are created in all contexts is always autogenerated. However for parts, users in a project or program context can override the generated number by editing the Part Number field when creating a part. You can remove the ability to override the autogenerated part number by adding the following constraint algorithm in the object initialization rule for WTPart from either the site or organization context:
com.ptc.core.rule.server.impl.GetImmutableConstraint
By including this algorithm in the site context, the Part Number field is no longer editable when creating a part from all contexts. By including this algorithm in a specific organization context, only the organization and all contexts created under the organization are affected by the rule change. If your site uses the capability to move parts between projects, between programs, or between a project and a product or library and wants to keep the number assigned to the part, then you should consider including this algorithm.