not for profit consulting 6. The accounting benefit is bound by the prudent principle. According to the principle of prudence, when there are a variety of accounting methods to choose from an economic business of an enterprise, it should choose a method that neither overestimates nor depreciates the benefits. Enterprises manipulate profits to achieve homogenization of profits, most of which adopt the method of overestimating earnings, and the subjective selection of the period of value-added. The level of productivity of society determines the organizational form of social basic economic units. Enterprise is the result of the development of social productive forces to a certain level, which is the product of commodity production and exchange of goods. Followed by Edwards and bear published in his 1961 book "the theory of corporate earnings and measurement of the current operating profit is defined as the sales revenue more than the amount of current production and cost of sales, which can realize the cost savings is in this issue of asset price increases, which can realize the history of the cost savings are the pin commodity costs and the difference between the current purchase price; The realized capital gains are the amount of sales revenue greater than the historical cost when dealing with long-term assets. They argue that "these incremental sums provide investors with a reasonable starting point for measuring the scale of relative affluence and a detailed analysis of the company's operating results and comparable financial conditions". They stress that any full income analysis should take into account both realized and unrealized benefits and classify them by source. When are advantageous to occur, such as no record, will not only lead to current income can't reflect, but also can lead to later to sell assets to income and related costs to wrong ratio; Operating earnings and, on the other hand, the production gains is usually produced by different management decisions, and adopted different circulation form, therefore, make the same comment on both, will weaken the role of the income statement. The investment of securities provides an important means for the central bank to conduct financial macro-control, which is of great significance to the sustainable and efficient development of the national economy. Competition refers to the economic subject in order to maintain and expand their own interests and take all sorts of behavior, the behavior of self-protection and expansion efforts in product quality, price and service advantages, varieties, etc. Network planning technology is a scientific method of planning and management, which is developed with the development of modern science and technology and industrial production. In the 1950s, in order to meet the needs of scientific research and the management of new production organizations, some new methods of planning management were introduced abroad. In 1956, dupont studied the key line method of network planning technology (CPM) and tried it on a chemical engineering project, and achieved good economic results. In 1958 the United States naval weapons when "Polaris" missile plans, applied the plan evaluation method (abbreviated as PERT) project plan arrangement, evaluation, audit and control, was a huge success. In the early 1960 s, the network planning technique, has been in the United States all new construction fully adopt this kind of new method for program management, could be introduced into Japan and Western Europe and other countries. With the rapid development of modern science and technology and the continuous improvement of management level, network planning technology is also developing and improving. At present, it has been widely applied in the fields of industry, defense, construction, transportation and scientific research of the world, and has become a scientific method of modern production management in developed countries.