In companies that do bottom-up budgeting, managers aren’t given specific targets. Instead, they begin by putting together budgets that they feel will best meet the needs and goals of their respective departments. These budgets are then “rolled up” to create an overall company budget, which is then adjusted, with requests for changes being sent back down to the individual departments.
http://www.ilmpm.lmmattersonline.com/courses/hmm10/finance_essentials/bottom-up_budgeting.html
This process can go through multiple iterations. Often it means working closely with other departments that may be competing against yours for limited resources. It’s best to be as cooperative as you can with other departments during this process, but that doesn’t mean you shouldn’t lobby aggressively for your own unit’s needs.
