Original Post Date: Thursday, March 10, 2011

My previous blog discussed a “Should Cost” methodology used by PRICE Systems to complete an analysis. In the article I included a chart depicting calibration results for manufacturing complexities for each weapon system (X-Axis). Manufacturing complexities are a major cost driver within the model. This parameter can be derived from model knowledge tables, generators or from calibration. Many times the calibrated results are simply averaged and used for predicting cost for the new system. This assumes that the new system is very similar in technology and performance as the systems used for calibration. In general this is not the case. Below I discuss how data driven cost estimating relationships (CER) can be developed between the calibration results and a selected independent variable. The CER will then be used to derive the manufacturing complexity, which then matches much closer to the new technology.

Figure 1. Calibration Results for each Weapon System

Since the data was already collected and calibrated within the model, the next step was to identify an independent variable. For manufacturing complexity for structure, thrust was selected. However, other variables could have been selected.  Maximum take-off weight, range, ceiling, empty weight, thrust per pound, or speed were all candidates for an independent variable. For manufacturing complexity for Electronics, frequency speed was selected as an independent variable. Again there are many potential candidates for an independent variable for electronics. 

The next step was to graph and complete regression analysis. Figure 2, depicts the results for manufacturing complexity for structure, and figure 3, depicts the results for manufacturing complexity for electronics.  I normally select a power function when regressing data. One could select any function except linear. Linear regression does not always work very well and as a practical matter technology advancements are rarely linear. 

 
Figure 2.  Manufacturing Complexity for Structure 

Figure 3. Manufacturing Complexity for Electronics

Using the above equations now require information be collected on the aircraft thrust requirement for structure, and frequency speed for electronics. These requirements are then used to calculate the appropriate manufacturing complexity. This approach insures that the cost estimate now match up with the requirements. 

The next time you need to complete a cost analysis, talk to one of our expert PRICE Solutions consultants for help.