Homework 2: MedFRS Cost Estimation

Due Wed 9/13

CSCI 510, Fall 2017

30 points

Preparation

Become familiar with EP-2: Chapter 2 of the COCOMO® II cost model book. Use Table 2.50 for the COCOMO® II cost estimation parameters, or EP-0.

Become familiar with Sections 5.4, 6.6, and 7.6 of the ICSM book. These describe the Medical First Responder System (MedFRS) used as an example project using the ICSM.

Assignment

The total software portion of the $2 million budget for the initial operational capability of the MedFRS system, excluding the deferred Electronic Health Record (EHR) system, is $600K. To provide feasibility evidence of the $600K budget, Table 7-3 of the ICSM book proposes a prototype of the new integrated patient-monitoring systems and 4G communications on a single first-responder vehicle and one level 1 trauma center.

1.(15 points). Perform a COCOMO® II cost and schedule estimate for developing the prototype, using the following parameters: a prototype size estimate of 5 KSLOC and an average developer cost of $8K per person-month. The COCOMO® II parameter ratings are all Nominal (round off the all-Nominal exponent to be 1.10) except for:

RELY: Low; since the prototype will not be operational

CPLX: High; some complex cross-device and external interfaces

ACAP: Very High; prototype needs top talent

PCAP: Very High; prototype needs top talent

APEX: High; prototypers are familiar with medical field

PLEX: Low; prototypers unfamiliar with new devices

RUSE: Low; prototype code will not be reused

(EAF = Effort Adjustment Factor = product of all effort multipliers = product of all non-Nominal effort multipliers.)

Solution for Prototype (15 points total):

Solution for Prototype EAF (3.5 points; give deductgive 0.5 points for each numerically incorrect effort multiplier value):

EAF= 0.92*1.17*0.71*0.76*0.88*1.09*0.95

= .529

Solution for Prototype Effort (5.56 points = 2.53 for basic form of equation + 1 for “2.94” and “1.10” + 2 for correct answer):

Prototype effort= A * (Size ^ E) * EAF

= 2.94 * (5 ^ 1.10)* .529

= 2.94 * 5.87 * .529

= 9.13 person-months

Solution for Prototype Schedule (3 points = 2 for basic form of equation + 1 for correct answer):

Schedule exponent = F= D + 0.2 * (E – B)
= 0.28+0.2*(1.1-0.91)
= 0.318

Prototype schedule (TDEV)= C * (PM ^ F)
= 3.67* (9.13 ^ 0.318)

= 7.41 calendar months

Solution for Prototype Cost (3 points = 2 for basic form of equation + 1 for correct answer):

Prototype cost ($)= Effort in person-months * Cost per person-month

= 9.13 * $8K

= $73.1K

2.(15 points). Assume that the prototype has been successful. The prototype has not only provided evidence of feasibility of the approach, but also has determined the likely size of the full development to be 21 KSLOC, and provided evidence for lower ratings for the system’s complexity CPLX (now Nominal due to experience with the prototype). However, the full team will include the prototypers and new, less-capable and less-experienced developers, reducing ACAP and PCAP from Very High to High, although PLEX is improved to Nominal and RUSE is set to High to enable reuse among the Ensayo hospitals. It also reduces the team’s average salary to $7K per person-month.

For the full system, perform a COCOMO® II cost and schedule estimate, assuming that the average developer cost is $7K per person-month, and the remaining COCOMO II parameter ratings are all Nominal (round off the all-Nominal exponent to be 1.10), leaving the following non-Nominal ratings

RELY: Very High; since the system needs to be safety-critical

ACAP: High; some Nominal-capability analysts added to team

PCAP: High; some Nominal-capability programmers added to team

APEX: High; some Nominal-experienced developers added to team

RUSE: High.

Solution for System Development (15 points total):

Solution for EAF (2.53 points; 0.5 points for each numerically correct effort multiplier value, plus 1.00.5 (because there are only 5 non-Nominal effort multipliers)):

EAF= 1.26 * 0.85 * 0.88 * 0.88 *1.07
= .887

Solution for System Development Effort (3.5 points = 2 for basic form of equation + 1.5 for correct answer):

System development effort= 2.94 * (21 ^ 1.10) * .887
= 74.3 person-months

Solution for System Development Schedule (3 points = 2 for basic form of equation + 1 for correct answer):

Note that E is the same here as for the prototype, so the exponent (0.318) is the same.

System development schedule (TDEV)
= 3.67 * 74.3^0.318
= 14.4 calendar months.

Solution for System Development Cost (3 points = 2 for basic form of equation + 1 for correct answer):

System development cost= 74.3 * $7K
= $520K

Does the total cost and schedule of the prototype and full development fit within the $600K budget and 24-month schedule?

Approach to budget and schedule analysis (2 points):

Calculate total system cost and schedule and compare to computed budget and schedule (approach can be right, even if numbers are wrong):

Total system cost= $73.1K + $520K = $593.1K < $600K budget. Fits.

Total system schedule= 7.41 + 14.4 = 21.81 months <24 monmths. Fits.

Correct budget and schedule analysis result (1 point):

Total system cost and schedule fit within budget and schedule.

Grading Notes

  • Show all your work – the equations you used, the parameter and cost driver values, intermediate steps, etc. The more work you show, the more partial credit you will be able to receive.
  • You must use the cost and schedule estimation equations from EP-2 (also given in EP-0). You cannot use the COCOMO® II program to provide the answers (though, you may use it to double check your work). Note: you will not be able to use the COCOMO® program in exams, hence, it will be more beneficial for you to apply the equations from EP-2.
  • Be sure to specify the units of your values, where they apply (such as, PM, $, K, etc.).
  • Review the D2L Discussion Board posts “COCOMO: Assumptions for 510” and “Rounding for 510” under Homework in General. The assumptions explained in these posts apply to this assignment. Failure to follow guidelines in these posts will result in a reduction of points.