The simple circular diagram, which shows the four P's focu­sing upon the customer, emphasizes the variables which the marketing manager can control. But the actual situation is more, complex.
Since marketing does not exist in a vacuum, certain external factors must be considered. These factors limit the marketing manager and he must work with or around them. They can be placed in the following categories:

1.      Cultural and social environment,

2.      Political and legal environment,

3.      Economic environment,

4.      Existing business structure,

5.      Resources and objectives of the firm.

The interrelations of these particular variables can be seen more clearly if a new diagram is drawn. Figure 4 shows the four controllable variables the components of a marketing mix in the center of a larger circular diagram. On the outer ring are these live new variables, which the marketing manager cannot change or even control in the short run, but which he must always bear in mind when planning his marketing strategies. In the long run his actions may affect these factors and this will affect his future strategies; but current planning usually must take these factors as given.
As seen from this viewpoint, marketing is truly an integrating discipline. The marketing manager must seek ways to relate and interrelate the findings and analytical approaches of many other disciplines. Much of the work being done in the areas of sociology, anthropology, psychology and social psychology is concerned with gaining a better understanding of the cultural and social environment.

                                              UNCONTROLLABLE FACTORS
                                                          Figure 5

The Marketing Manager's Variables            
The traditional fields of political science, history, philosophy, law and economics envelop the political and legal environ­ment. The fields of economics and business administration, as well as the natural sciences and engineering, are relevant to the economic environment. And business administration and eco­nomics are concerned with the existing business structure, as well as the resources and objectives of the firm.

3.1.  Political And Legal Environment

As the role of business grows in our society, the reactions of the populace, politicians and government become more impor­tant to the individual business manager and marketing mana­ger.

3.2.  Economic Environment

The marketing manager must consider carefully all potential fluctuations in the level of economic activity in the country or countries he selects as target markets. An extremely good marketing strategy may still fail ifa country is experiencing a depression or a rapid decline in business. Business cycles make the contribution of economists important to the marketing manager. A knowledge of macroeconomics (the behavior of whole economic systems) is especially relevant. Here the plans of the business community to invest and of the government sector to spend, may have an impact on the overall level of the economy Consumers1 willingness to buy and the probable reaction to proposed.

3.3.  Existing Business Structure

The existing business structure refers to the competitive stuation facing the marketing manager. Here he must appraise the degree of competition lacing him in various target markets and the nature of marketing strategies being used (or probably be­ing considered) by competitors.

3.4.  Resources And Objectives Of The Firm

Two separate variable are involved here, resources and objec­tives. Both are important because while top management, pre­sent or past, may have set these variables, in the long run the marketing manager may be able to modify them.