I think that this is an activity that would be best served by an engineering study by a consultant.
The advantage to paying an experienced firm for a study is that any type of plant layout involves tradeoffs. A consultant can point these out, and in many cases, place a financial value on alternatives.
Additionally, a consultant can point out OSHA and other layout pitfalls that can cost a lot of money to correct.
Finally, having a study in hand proves to management that you are a reasonable, responsible individual who only has the companies best interests in mind...(and it insulates you from many bad decisions that could haunt you for many yers to come !!!)
My opinion only
-MJC