i mean that if have a product or assembly part and i want to scale it then how i will do it?
Insert a co-ordinate system- Then Insert-Transformation feature-scaling. Chose the newly defined co-ordinate system as the reference. Chose the ratio of old to new, select the body and OK.
Scaling doesn't work in assemblies. You need to convert the assembly as a CATPart fileand then use the scale function.