Any deviation from the plans can then be rectified through some type of intervention in the operation, which itself will probably involve some replanning. Deviations because of this plan are considered via a replanning activity and also the necessary interventions made to the job centre that can (hopefully) make certain that the new plan is carried out. Eventually, however, some additional deviation from planned activity is going to be detected along with the cycle is repeated. One portion of control, then, is periodic intervention in the activities of the operation. An important decision is how this intervention takes place. This article discusses the easiest way the best client billing software on your business. First, you must learn your preferences. What are you searching for currently billing software? Second, do you require a desktop application or a web-based program? Third, is the time tracking system software user-friendly? Fourth, how affordable is the time and expense software? (2) actual income -- the increase of material wealth; Famous British economist hicks and others argue that the above theory did not consider the factor of income, and therefore unable to determine the level of interest rates, in 1937, and puts forward the is-lm model on the basis of general equilibrium theory. It establishes a theory of interest rates and income at the same time that the four factors of savings and investment, money supply and monetary demand interact. The orderly performance of the market ensures equal competition and fair trade, protecting the legitimate rights and interests of producers and operators and consumers. The investment in securities is conducive to improving the operation and management of enterprises, improving the economic and social visibility of enterprises and promoting the rationalization of enterprises' behaviors.