This paper focused on the analysis and respectively, the diagnosis based on costs gaps is distinguished by logical and economic construction of models in which variables are aggregated-factors that reflect essences of the company s functions efficiency as a system. They lead to the development of a factorial analysis and respectively, a causal-deterministic. PhD Professor Aurel Isfanescu, Nicolae Titulescu University. The work fits into all operational tools in its internal management. Factorial analysis models of gaps allow the detection and evaluation of a central model of business functions efficiency, effectiveness related to volume, use and consumption of factors of production. PhD Professor Radu Florea, University of Pitesti. Centered on a key issue, of substance of any business activity producing goods and services, this paper provides an applied methodological, complex device, to analyze and diagnose the business costs. PhD Professor Vasile Robu, Academy of Economic Studies Bucharest.