This means that the product of the time and effort coupled with the process productivity of the development organization determines how much function can be delivered. Extensive empirical study of software data has shown that very strong linearity's exist in software behavior. This is taken into account by the form of the software equation and discloses how these non-linearity's can be exploited by management. It is determined from historical data. Size is the quantity of function created in source lines of code written, function points, objects, or other measures of function.
Effort is the development effort required.
It includes all categories of labor used on the project. Effort is consistent with the time specified below. B is a complexity adjustment factor. It provides for specialized skills for integration testing, documentation, and management as the size of the system increases. SLIM is applicable to all types and sizes of projects.