Fired, let go, quit, whatever. What you have is a mangement problem, not a Mathcad problem. These people improve the worksheets, but apparently you have no change control in place to track the chnages, let alone validate that the changes are correct. The only thing you could do in Mathcad is lock the worksheets so that changes are not possible. That just means you won't get any improvements though. If you want the improvements to be available to everyone then mangement has to introduce policies to make that happen. Mathcad cannot do it.
