What is the purpose of obligatory and optional properties of the objects? ( WinRunner Questions )

What is the purpose of obligatory and optional properties of the objects? ( WinRunner Questions )

For each class, WinRunner learns a set of default properties. Each default property is classified “obligatory” or “optional”.

• An obligatory property is always learned (if it exists).


• An optional property is used only if the obligatory properties do not provide unique identification of an object. These optional properties are stored in a list. WinRunner selects the minimum number of properties from this list that are necessary to identify the object. It begins with the first property in the list, and continues, if necessary, to add properties to the description until it obtains unique identification for the object.