QFD (Quality Function Deployment) Value engineering is also called "VE".
It is easy to understand that the target of VE is a machine. But systems (software, companies and so on) that is collection of functions are also the target.
"V = F / C" suggests the strong point of VE. It is also used the image of VE.
V is "Value". F is "Function. C is "Cost". If the cost is high value is low even if the function is high.
The value of F is defined by price in VE.
Ideal definition is that F is the value of customers. Other definitions are "The selling price" , "estimated price by customers" and "estimated price by engineers". In many cases, "estimated price by engineers" is often used.
The price of F is often called "target cost" because the difference between F and C is used to decide the target of function to improve.
C is also difficult to define.
Ideal definition is that C is the life cycle cost . But this is too difficult to estimate. In many cases, the cost of production is used.
If F is the value of function for customers and C is the life cycle cost, V might be the size of the significance of existence.
But if F is the taget cost and C is the cost of production, it is the value for the maker.
For example, the car has the function to move, to stop to curve and so on. And each function has small functions.
VE define each function as the form of "a noun and a verb".
The analysis of each function indicates us the target to improve clearly. VE define the production is the collection of functions not parts. This viewpoint is closer the viewpoint of customers than that of makers.
If the value of F and C is calculated, we understand the target to improve numerically.
We estimate the importance of each function by One to one comparison . If we define the total F of the production, we can calculate the value of each function by the importance.
If we study the relation of each function and each part by matrix diagram , we can calculate the costs of each function by the costs of parts.
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