There are different problem associated with the input data for real world liner programs which are listed below

• Error committed while measuring

• It is not stable, it changes over time

• Only an educated fellow can guess

• In the process of real world linear programming, there can be model error

• Prospective studies

• Scenario analysis

• Linear program approximates and geometric model

To attain a very good result, we need to be able to observe how the optimal value and solution change as the input problem data change.

There are many graphical way of explaining of all these listed above but I would like to be theoretical because when you know the theory you would be able to practice the theory you know.

THE THEORY OF LINEAR ECONOMICS MODELS

Under the theory of linear economics model, I can sub divide it into three and they are listed below:

• The production model

• Duality

• The optimal value and the marginal value

THE PRODUCTION MODEL

The products are obtained from their raw materials and they are restructured or redefined to look different. Profit is the difference between the cost price and the sale price of the restructured or redefined form as products. When you make a profit, it simply means that you sold the raw materials more than the price you bought them.

THE OPTIMAL VALUE AND THE MARGINAL VALUE

This is employed in the study of how much the production process increase the value of raw materials. Just like this question, on a per unit basis, by how much does the production process increase the value of raw materials? This part of the theory involves some linear calculation.

DUALITY

In the market area, producers compete for raw materials or any input to production. This multitude competition is the determinant of the price for goods in the market area.

There is a mathematical way of how prices are set. Let consider the market as an agent that is separate in the market place. It is the agent that sells and at the same time he is the one that owns the raw materials needed for production.
The market does not have the intention to remove the producer out of business; it just wants to take all of their profit.

Recall the aim of the market

The market has the intention of making the most money possible from its resources by setting the highest prices it can without counting the producer out of business.

The marginal value gives the per unit increase in the value of the resources due to the production process, from this we can say marginal values are the solution to the dual.