Work Package 4.3 - Chapter Problems

1. Using the cost estimation template and Actuals in Figure 7-5, compare the model in the figure with the following estimates derived from a multiplicative model. Base your comparison on the mean bias, the MAD, and the tracking signal. Comment.

Period: 1 2 3 4 5 6 7 8

Estimated: 179 217 91 51 76 438 64 170

* Original: Mean bias: 139.375 MAD: 93.08 TS: 28.75

* New #s: Mean bias: 167.5 MAD: 149.18 TS: -21.63

* To be honest, this and the following problem were hard to understand based solely on the material presented in the book. The mean bias was reached by taking the average of all the estimate numbers. The MAD & TS were reached by taking the SUM of each of the numbers MAD/TS numbers. Based on this, the Mean Bias and MAD both grew substantially, while the TS actually became a negative number.

2. Repeat Problem 1 but using the template in Figure 7-6 based on the MAR instead.

* Original: Mean bias: 139.375 MAD: .970 TS: 27.768

* New #s: Mean bias: 160.75 MAD: 66.305 TS: -24.180

* Once again, this and the previous problem were hard to understand based solely on the material presented in the book. The mean bias was reached by taking the average of all the estimate numbers. The MAD & TS were reached by taking the SUM of each of the numbers MAD/TS numbers. Based on this, the Mean Bias and MAD both grew substantially, while the TS actually became a negative number.

3. N/A

4. N/A

5. A production lot of 25 units required 103.6 hours of effort. Accounting records show that the first unit took 7 hours. What was the learning rate?

* Tn=T1nr 103.6=7(25)r 14.8=25r ln(14.8)=r*ln(25) r=ln(14.8)/ln(25) r=.837133

* Learning Rate = .837133

6. If unit 1 requires 200 hours to produce and the labor records for an Air Force contract of 50 units indicates an average labor content of 63.1 hour per unit, what was the learning rate? What total additional number of labor-hours would be...