Limit on maximum number of attributes on an object

We have to create an Product Specification document (WTDocument Subytpe). This will have about 40 attributes. Wanted to know if there is a recommended limit on maximum number of attributes (Local or Global) which can be added to an object. Looking from the point of view of search and other performance issues.

Also, we will be adding cascading attribute constraints to control the selection of the values.

Windchill PDMLink Version 11.2 or 12.0