How to keep record of arms and payments?

All the armies in the world purchase arms to defend their homeland. The main problem is they buy these arms in bulk quantity from the industry so keeping the record of these arms is the most important thing and to which soldier a weapon is alloted, and the salaries of the soldiers is another thing as well where accountancy is needed. These armies usually have accountants who manage payroll services for their clients, it is somehow similar to business payroll services as well.