Computer Aided Bucket Elevator Re-Design

I have no specific information, but for sure you can find such a kind of software for screw conveyors or other industrial devices.
Generally these softwares can be found on the internet sites of producers, as a form of assistance to define what you need to ask and buy.

As you understand computer assisted design means that those who wrote the software, made the real design according to their knowledge, preferences and necessities and those who are using the "designing software" are just getting another copy of several very similar machines.

Sometimes some producers, following their own and their customers' experiences, develop some software to determine the dimensioning of the machine. Sometimes the software is more sophisticated and is simulating the functioning parameters and the capacities of the machine. So you can understand the function of a line, a lay out or a complete plant before building it.
These software are generally reserved and part of the company "know how" seldom these are free ware.

Do you really desire to revise the design of an old bucket elevator ?

Start from the Mark's Mechanical Engineers Handbook, then move to more specialist books, in some time, a week or two according to your spare time and learn speed, you will be able to write your own software, but most of all you will understand the function of your own machine, its ways, its defects. If you have no other activities in 2 days you can get your first answers.

Generally commercial simulations are superficial and aimed to pilot you to buy a specific product, do not trust them too much: for you the machine will remain a black box.
A professor at university was teaching: "Before buying a machine roughly try to figure out how you would design it, than you know what you need."

Thanks. I have already started to study as you say. However, my boss insists in the software thing and wants at least to know some packages. I suppose she will quit that after looking at the prices.

As i told, the best way to find existing SW would be looking for bucket elevator producer's sites and check if they have specialistic software for what they are selling.

Generally these are Excel sheet & data collection, or small Visual Basic prgm to simulate the machine and dimension it.
You need to make a analitic study of the machine and possibly make extensive use of proper formulas.
In past times i got to make some researches on conveyors and bucket elevator too. So I shall write to your private address to give you deeper info.