Costing system is an important tool of a management decision making. W
ithin the scope of entrepreneurial activity a great number of prelimin
ary calculations on the level of operating management and on the level
of business management is being done. Costing is often considering tw
o aspects: the aspect of time and the aspect of cost accounting. Preli
minary costing determines the need of the so called starting-up capita
l. It involves income costing, expenses costing, operating results cos
ting and the analysis of anticipated profitability. Decision making ap
plies the opportunity costs. Costing of ''non-total'' costs is trying
to eliminate negative elements of costing of total costs. Costing of n
on-total costs is characterized by dividing the costs into directly an
d indirectly corresponding unit costs, by category of gross profit and
by retrograde approach to calculation. The well-known systems of cost
ing on the basis systems of variable costs with timely differentiated
fixed costs, costing of standard marginal price and costing of relativ
e direct costs.