what is the Max limit of creating rule inputs in an expression or in a Interface?

There may be but I am not aware of what it might be. Why do you want to know? Note that the more inputs to either object type the less understandable./maintainable the object is likely to become.

just wanted to know the effect , as i have many interfaces in my app which have more than 20 rule inputs.

Without a review of the interfaces it's hard to say if they're poorly designed (i.e. perhaps they should be decomposed into smaller objects with less rule inputs each). The effect is likely to be around understanding who they work and the effort required to full test them. There are no real run-time effects as a rule input is simply a "pointer" to a piece of memory that holds a value and whether you have one interface with 20 rules inputs, or 4 interfaces with 5 rule inputs each the run-time effect is the same.

Without a review of the interfaces it's hard to say if they're poorly designed (i.e. perhaps they should be decomposed into smaller objects with less rule inputs each). The effect is likely to be around understanding who they work and the effort required to full test them. There are no real run-time effects as a rule input is simply a "pointer" to a piece of memory that holds a value and whether you have one interface with 20 rules inputs, or 4 interfaces with 5 rule inputs each the run-time effect is the same.

Stewart Burchell said:

There are no real run-time effects as a rule input is simply a "pointer" to a piece of memory that holds a value and whether you have one interface with 20 rules inputs, or 4 interfaces with 5 rule inputs each the run-time effect is the same.

I lilke that explanation very much! Very valuable explanation. :) Thank you stewart. I was never thinking of an RI like that, but it makes absolutly sense.

It took me ages to realize this was the case. What fools you into thinking they are something more is that when you edit an Expression or an Interface the relevant Designer allows you to assign values to them, which makes you think they are actual containers of data. Once you understand they're simply pointers then mapping them (especially in User Input tasks in a Process model) makes way more sense!