COCOMO II Model Overview

COCOMO II Model:
1.Source Lines of Code(SLOC)
a.SLOC 是logical line ( If-else-endif) 視為一個 SLOC
b.Comment 不計算在SLOC
c.宣告算在SLOC

2.Cost Drivers:
a.Effort = 2.94 * EAF * (KSLOC)^E
Where EAF=Effort Adjustment Factor derived from the Cost Drivers
E=an exponent derived from the five Scale Drivers
例如,EAF=1.00, E= 1.0997,8,000 source lines of code

Effort = 2.94 * (1.0) * (8)^1.0997 = 28.9 Person-Months

3.Effor Adjustment Factor:
a.Complexity (effort multiplier of 1.34)

b.Language & Tools Experience (effort multiplier of 1.09)
c.the others normal ,set 1.00
Effort Adjustment Factor = EAF = 1.34 * 1.09 = 1.46

Effort = 2.94 * (1.46) * (8)^1.0997 = 42.3 Person-Months

4.Schedule Equation:
a.Duration = 3.67 * (Effort)^SE
Where

Effort Is the effort from the COCOMO II effort equation

SE Is the schedule equation exponent derived from the five Scale Drivers

b. 0.3179 that is calculated from the scale drivers:



Duration = 3.67 * (42.3)^0.3179 = 12.1 months

Average staffing = (42.3 Person-Months) / (12.1 Months) = 3.5 people


5.SCED Cost Drivers:

a.Required Development Schedule(SCED)
b.代表若要加速工作進度，在樂觀的條件下，需要多少人力
c.SCED rating of Very Low corresponds to an Effort Multiplier of 1.43 (in the COCOMO II.2000 model)

d.means that you intend to finish your project in 75% of the optimum schedule .



Duration = 75% * 12.1 Months = 9.1 Months
Effort Adjustment Factor = EAF = 1.34 * 1.09 * 1.43 = 2.09
Effort = 2.94 * (2.09) * (8)^1.0997 = 60.4 Person-Months

Average staffing = (60.4 Person-Months) / (9.1 Months) = 6.7 people


Remember: SCED cost driver means "accelerated from the nominal schedule".