CSCI 510 Midterm 2, Fall 2021
Wednesday, October 27, 2021
3 questions, 100 points
Black/Blue Pen Only!
Assume the following, unless otherwise mentioned explicitly in the questions:
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The Post-Architecture model is used (not the Early Design model);
There is no Adapted (reused) software (i.e., all software is new);
Requirements Volatility (REVL) is zero;
There is no automatic translation;
The Inception and Transition phases are not part of the estimate (i.e., the model equations give the effort and
schedule directly);
 No risk reserves are needed;
 The nominal schedule is to be used (i.e., SCED% = 100%); and
 Only one module is to be produced.
Effort Multipliers not explicitly mentioned are rated as Nominal. The numeric value for any Effort Multiplier at the
Nominal level is 1.0.
When all Scale Factors are Nominal, you should use 1.1 as the value for the exponent E.
Use at least 3 significant digits for your final answer (and your intermediate results). More significant digits is
acceptable.
CS 510 Midterm 2
Fall 2021
October 27
1. COCOMO II Estimate, 30 points (graded by Michael)
1.1 (15 points) During the MedFRS Initial Operational Capability (IOC) development,
several factors caused the scope of the Full Operational Capability (FOC) to increase. The
smart stents for the monitoring of blood chemistry received FDA approval and were added
to the FOC, and a number of system-of-systems integration improvements were necessary.
Further, the demand for medical software engineers was growing steeply, causing high
personnel turnover and replacements with less expertise. As a result, the size of the FOC
software increased to 95 KSLOC, and the CPLX ratings went from High to Very High. And
with the personnel replacements, the High ACAP, High PCAP, and Very High PLEX ratings
went to Nominal, although their average cost decreased from $7.2K to $6.6K/personmonth. Also, the Team Cohesion (TEAM) scale factor decreased to Low. As a result, the
FOC budget was increased to $7000K, and the schedule increased to 31 months.
Compute the COCOMO II cost and schedule estimates for the revised FOC project, assuming
that the RELY and DATA rating is Very High, and that all the other cost driver and scale
factors not mentioned above remained Nominal. Do the results fit within the revised
budget and schedule?
(Underlined Parenthetical Values indicate unrounded inputs and resultant values)
Total Scale Factor =
N-PREC + N-FLEX + N-RESL + L-TEAM + N-PMAT =
3.72+ 3.04+4.24+4.38+4.68 = 20.1 (20.06)
Exponent =
0.91+ 0.01 * 20.1 = 1.11 (1.1106)
EAF = Values of VH-RELY * VH-DATA * VH-CPLX = 1.26 * 1.28 * 1.34 = 2.16 (2.161152)
[3 points for correct answer. Otherwise, 2 points if 2 values are right; otherwise 1 point if 1
value is right.]
Effort = 2.94 * 951.11 * 2.16 = 996 PM (998.8320736 PM).
[3 points for correct answer based on student EAF and Scale Factor. Otherwise, 1 point if
form of equation is right.]
Cost = 996 PM * $6.6K = $6570 K ($6592.291686 K)
[2 points for correct answer based on student Effort.]
F = 0.28 + 0.2 * (1.11 – 0.91) = 0.28 + 0.2 * 0.200 = 0.28 + 0.040 = 0.320 (0.32012)
Schedule = 3.67 * 9960.32 = 33.4 months (33.48602498 months)
[5 points for correct answer based on student Effort; otherwise, 2 points if form of equation
is right, plus another 1 point if F is correct.]
Meets project budget of $7000K but not project schedule of 31 months.
[2 points, with 1 point for each answer (budget and schedule) ]
CS 510 Midterm 2
Fall 2021
October 27
1.2 (15 points) In the course’s Risk Management lecture, one of the strategies for reducing
the risk of personnel turnover was to offer the team members a significant bonus for
working on the project through completion. Suppose that a 10% completion bonus would
cause the experienced team members to stay on the project, increasing the ACAP and PCAP
ratings from Nominal to High, and it would increase the PLEX ratings from Nominal to Very
High. The average cost per person-month would increase back to $7.2K; and an additional
10% of the project expenditures would be distributed for the 10% bonus.
Compute the resulting budgets and schedules for the proposed revised strategy. Do the
results fit within the revised budget and schedule?
EAF = 2.16 * H-ACAP * H-PCAP * VH-PLEX = 2.16 * 0.85 * 0.88 * 0.85 = 1.37 (1.374060442)
[3 points for correct answer based on student 1.1 EAF; otherwise 1 point if at least one
value is right.]
Effort = 2.94 * 951.11 * 1.37 = 631 PM. (635.0574326)
[3 points for correct answer based on student EAF; otherwise, 1 point if form of equation is
right.]
Salary Cost = 631 * $7.2K = $4540K ($4572.413515 K)
Completion bonus = 10% * $4540K = $454K ($457.2413515 K).
Total cost with bonus = $4540K + $454K = $4990K ($5029.654867 K)
[3 points for correct answer based on student Effort; otherwise, 1 point if form of any
equation is correct.]
F = 0.320 (from Question 1.1)
Schedule = 3.67 * 6310.320 = 28.9 months. (28.9669362 months)
[4 points for correct answer based on student Effort; otherwise, 2 points if form of equation
is right.]
Meets $7000K project budget, and the 31-month schedule.
[2 points, with 1 point for each answer]
CS 510 Midterm 2
Fall 2021
October 27
2. Present Value Analysis (40 points) (graded by Jincheng)
Another option for meeting the FOC budget and schedule is offered by a health services
company, HealthCo, who has provided a similar system for a regional confederation in
Colorado. They propose to satisfy the MedFRS FOC needs in 28 months, with an up-front
payment of $3 million, and a $40K payment at the beginning of each of the 28 months.
Compute the total cost and the present-value cost of the HealthCo option and the option in
question 1.2, assuming for simplicity that it has a 31 month duration, that salary payments
are made at the beginning of each month, that the bonus payments are paid at the end of
the 31st month, and that the staffing level is constant for the duration of the project. Take
the interest rate for discounting to be 0.50% per month.
Which option is better from a total cost perspective? From a present-value perspective?
Discount rate D = 1 / 1.005 = 0.9950248756(3SD, 3 significant digits: 0.995)
[2 points for correct answer. Otherwise, 1 point if form of equation is right.]
Question 1.2 option:
[23 points total.]
Total Cost = $5029.654867K (from question 1.2) (3SD: 4990K)
[1 point.]
Without-bonus salary per month, 31-month schedule = $4572.413515 K/31 =
$147.49721K/month (3SD: 4540K/31 = 146K/month)
[2 points for right answer based on student Question 1.2 Cost.]
Without-bonus salary: Present Value = PVs($147.49721K, 0.995, 31) =
$147.49721K * (1-0.99531) / (1-0.995) =
$147.49721K * 0.143254000410687 / 0.0049751244 = $4247.042623077964982K
(3SD: 4200K)
[10 points for right answer based on student numbers above (here and from Question 1.2).
Otherwise, 5 points if form of equation is right.]
PV (bonus) = $457.2413515K * 0.99531 = $457.2413515K * 0.8567460002=
$391.739699K (3SD: 389K)
[8 points for right answer based on student numbers above. Otherwise, 4 points if form of
equation is right.]
Total PV = $4247.042623077964982K + $391. 739699K = $4638.782322K (3SD: 4590K)
[2 points for right answer based on student numbers above. Otherwise, 1 point if form of
equation is right.]
CS 510 Midterm 2
Fall 2021
October 27
HealthCo option:
[11 points total.]
Total Cost = $3000K + 28 * $40K = $3000K + 1120K = $4120K
[3 points for correct answer. Otherwise, 2 points if form of equation is right.]
PV = $3000K + $40K * (1-0.995024875628) / (1-0.9950248756) =
$3000K + $40K * (1-0.869661552683769) / (1-0.9950248756) =
$3000K + $40K * 0.130338447316231 / 0.0049751244 =
$3000K + $1047.921111811644348 K = $4047.921111811644348 K (3SD: 4050K)
[8 points for right answer based on student numbers. Otherwise, 4 points if form of cash
series equation is right; otherwise, 2 points if form of sum is right.]
Comparison:
[4 points total.]
HealthCo Option Total Cost lower than Question 1.2 option:
$4120K vs. $5029.654867K (3SD: 4990K)
[2 points if answer is right based on student numbers.]
HealthCo Present Value also lower: $4047.921111811644348 K (3SD: 4050K) vs. $4638.
782322K (3SD: 4590K)
[2 points if answer is right based on student numbers.]
CS 510 Midterm 2
Fall 2021
October 27
3. True-False Questions. 30 points; 3 points each. (graded by Dr. Jim Alstad)
Put either “T” or “F” on the line preceding the statement. Grading will be based on this
alone, not any additional statements or explanations provided.
__F__ Q3.1. Diseconomies of scale can be avoided by increasing the project size. (EC-8
#22)
__T__ Q3.2. Assuming you are in the profitable segment of the net value curve, whether
the marginal value is greater than or less than the marginal cost indicates whether to
increase or decrease activity respectively. (EC-9 #7)
__F__ Q3.3. Li studied some actual projects that used XP, and found that the cost of change
flattened out as her projects developed multiple stories, eventually having little cost for
error fixes, new design, and refactoring. (EC-14 #32)
__F__ Q3.4. The ICSM can be considered a risk-driven process generator. The ICSM
common cases, then, are basically determined by patterns of risk. Under ICSM, there are
three possible answers to a risk evaluation: Negligible, Acceptable, and High but
Addressable. (EC-13 #4)
__T__ Q3.5. You are doing economic analysis on alternative solutions to a problem, using
the cost-effectiveness decision criterion that's most appropriate to the problem, and you
have determined what seems to be the optimal solution. Before accepting this as the final
solution, you should probably do a sensitivity analysis. (EC-8 #29)
__F__ Q3.6. To be successful, a prototype has to have a high probability of accurately
identifying the critical states of nature, but this is not required for other forms of
information buying. (EC-11 #20)
__T__ Q3.7. The expected value when using the Laplace Rule is sensitive to how the states
of nature are identified due to the equal probability assumption. (EC-11 #7)
__F__ Q3.8. The Exploration phase should identify and clarify system capability needs and
constraints, then identify and clarify candidate solution options. (EC-12 #2)
__T__ Q3.9. A key difference between a family of systems and a system of systems is that
the family of systems is typically owned and evolved by a single organization or vendor.
(ICSM #199-200)
__T__ Q3.10. In a linear programming problem similar to the one discussed in lecture, the
optimal solution may not be unique. (EC-10 #19)