As as934 stated, it depends on the business. Upper management decides what the company should focus on given prior experience, etc. Low-priority projects are often put on the back burner because of that main reason – they are not important at that point in time. I do believe that this is correct thinking because, from a business standpoint, changes or projects that can affect the business greatly should be taken into high priority or else the business will suffer. Canceling low priority projects and shifting resources to a higher priority project can speed up the project schedule time. This is a benefit for the company as time is then freed up, given the completion of the project. The increase in manpower can also allow for better production/output.