1. Why Do We Measure? assess the status of an ongoing project
track potential risks
uncover problem areas before they go “critical,”
adjust work flow or tasks,
evaluate the project team’s ability to control quality of software work products.
California State University, cs437, Fall 2007

2. Typical Project Metrics
Effort/time per software engineering task
Errors uncovered per review hour
Scheduled vs. actual milestone dates
Changes (number) and their characteristics
Distribution of effort on software engineering tasks
California State University, cs437, Fall 2007

3. Typical Size-Oriented Metrics
errors per KLOC (thousand lines of code)
defects per KLOC
$ per LOC
pages of documentation per KLOC
errors per person-month
Errors per review hour
LOC per person-month
$ per page of documentation
California State University, cs437, Fall 2007

4. Typical Function-Oriented Metrics
errors per FP (Function Point)
defects per FP
$ per FP
pages of documentation per FP
FP per person-month
California State University, cs437, Fall 2007

5. Why Opt for FP? Programming language independent
Used readily countable characteristics that are determined early in the software process
Does not “penalize” inventive (short) implementations that use fewer LOC that other more clumsy versions
Makes it easier to measure the impact of reusable components
California State University, cs437, Fall 2007

6. Comparing LOC and FP
Representative values developed by QSM (Quantitative Software Management)
California State University, cs437, Fall 2007

7. Conventional Methods: LOC/FP Approach
compute LOC/FP using estimates of information domain values
use historical data to build estimates for the project
California State University, cs437, Fall 2007

8. Example: LOC Approach
Average productivity for systems of this type = 620 LOC/pm.
Burdened labor rate =$8000 per month, the cost per line of code is approximately $13.
Based on the LOC estimate and the historical productivity data, the total estimated project cost is $431,000 and the estimated effort is 54 person-months.
California State University, cs437, Fall 2007

9. Example: FP Approach The estimated number of FP is derived:
FPestimated = count-total 3 [ S (Fi)]
FPestimated = 375
organizational average productivity = 6.5 FP/pm.
burdened labor rate = $8000 per month, the cost per FP is approximately $1230.
Based on the FP estimate and the historical productivity data, the total estimated project cost is $461,000 and the estimated effort is 58 person-months.
California State University, cs437, Fall 2007

10. Problems
PROBLEM 1: A PhD researcher was hired as a consultant to analyze the team's requirements and design of an important large software project. The software was to be written using C++. The consultant came up with a total of 1,250 FPs for your design. How long will it take to your software team of 8 people to complete the project? Make the necessary "reasonable" assumptions.
Answer
50[LOC/day]*20 [days/month] = 1,000 [LOC/month]
66 [LOC/FP]*1250[FP] = 82,500LOC
82500[LOC]/1000[LOC/pm] = 82.5[person-month];
82.5[pm]/8[p] = [m].

11. A. 63[LOC/FP]*1000[FP]= 63,000[LOC];
PROBLEM 2: A given project written in Java (refer to ch22) has been estimated to include 1000 FPs. Make a “reasonable” assumption for the LOC generated by a programmer in a month and for the cost per LOC to calculate the overall cost of the project and the number of people needed to complete it in one year.
A. 63[LOC/FP]*1000[FP]= 63,000[LOC];
63,000[LOC]/620[LOC/pm]=102[pm]; 102[pm]/12[m]=8.5[p];
13[$/LOC]*63000[LOC]=$ 819,000.
PROBLEM 3: In the previous problem do not translate the work into LOC but simply use FPs directly. Make “reasonable” assumptions regarding the cost per FP and the average productivity of a person*month to calculate the overall cost of the project and the number of people needed to complete it in one year.
1000[FP]*1230[$/FP] = $ 1230,000;
1000[FP]/6.5[FP/pm]=154[pm]; 154[pm]/12[m]=12.8[p].
California State University, cs437, Fall 2007