ABSTRACT
The percentage varies according to the class of business and the basis upon which it is calculated, being sometimes as low as 30 per cent. when calculated upon the combined cost of wages and materials, and as high as 100 per cent. when calculated upon the wages alone. This oncost is generally added as a percentage, sometimes upon the wages alone, sometimes upon the wages and materials, and occasionally upon the materials only. The data for there account, is very carefully collected and recorded, and the value of these records to the manager of an engineering concern is incalculable. The three elements in the cost of a job are Direct Wages; Materials and Direct Charges; and Indirect Charges, generally called "Oncost". The prime cost of jobs fluctuates through rises or falls in prices of raw materials and this, under percentage on shop cost plan, would tend to upset oncost in a year of violent changes in prices of raw materials.
