The benefit of a common-size balance sheet is that an item can be compared to a similar item of another company regardless of the size of the companies.
A company can also compare its percentages to the industry's average percentages.
For example, a company with Inventory at 4.0% of total assets can look to its industry statistics to see if its percentage is reasonable.
(Industry percentages might be available from an industry association, library reference desks, and from bankers.
Many banks have memberships in Risk Management Association (RMA), an organization that collects and distributes statistics by industry.)
A common-size balance sheet also allows two businesspersons to compare the magnitude of a balance sheet item without either one revealing the actual dollar amounts.