diff options
| author | dwheeler <dwheeler@d762cc98-fd17-0410-9a0d-d09172385bc5> | 2006-07-07 13:36:27 +0000 |
|---|---|---|
| committer | dwheeler <dwheeler@d762cc98-fd17-0410-9a0d-d09172385bc5> | 2006-07-07 13:36:27 +0000 |
| commit | 05095851346f52c8e918176e8e2abdf0b21de5ec (patch) | |
| tree | 8de964f5eea4c7d80faf34d5d744e215a053ba8f /table.html | |
| download | sloccount-master.tar.gz | |
git-svn-id: svn://svn.code.sf.net/p/sloccount/code/trunk@1 d762cc98-fd17-0410-9a0d-d09172385bc5
Diffstat (limited to 'table.html')
| -rw-r--r-- | table.html | 569 |
1 files changed, 569 insertions, 0 deletions
diff --git a/table.html b/table.html new file mode 100644 index 0000000..81474a3 --- /dev/null +++ b/table.html @@ -0,0 +1,569 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><title>table</title><meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"></head><body><br> +By default SLOCCount uses a very simple estimating model for effort and schedule: +the basic COCOMO model in the "organic" mode (see below for more about this). + This model estimates effort and schedule, including design, code, test, +and documentation time (both user/admin documentation and development documentation). +Basic COCOMO is a nice simple model, and it's used as the default because +it doesn't require any information about the code other than the SLOC count +already computed.<br> +<br> +However, basic COCOMO's accuracy is limited in part for the same reason - +basic COCOMO doesn't take a number of important factors into account.<br> +If you have the necessary information, you can improve the model's accuracy +by taking these factors into account. You can at least quickly determine +if the right "mode" is being used to improve accuracy. You can also +use the "Intermediate COCOMO" and "Detailed COCOMO" models that take more +factors into account, and are likely to produce more accurate estimates as +a result. Take these estimates as just that - estimates - they're not grand +truths.<br> +<br> +To use the COCOMO model, you first need to determine if your application's +mode, which can be "Organic", "embedded", or "semidetached". Most software +is "organic" (which is why it's the default). Here are simple definitions +of these modes:<br> +<ul> +<li>Organic: Relatively small software teams develop software in a highly +familiar, in-house environment. It has a generally stable development +environment, minimal need for innovative algorithms, and requirements can +be relaxed to avoid extensive rework.</li><li>Semidetached: This is an intermediate +step between organic and embedded. This is generally characterized by reduced +flexibility in the requirements.</li><li>Embedded: The project must operate +within tight (hard-to-meet) constraints, and requirements and interface specifications +are often non-negotiable. The software will be embedded in a complex environment that the software must deal with as-is.<br> + </li> +</ul> +By default, SLOCCount uses the basic COCOMO model in the organic mode. For +the basic COCOMO model, here are the critical factors for --effort and --schedule:<br> +<ul> +<li>Organic: effort factor = 2.4, exponent = 1.05; schedule factor = 2.5, exponent = 0.38</li><li>Semidetached: effort factor = 3.0, exponent = 1.12; schedule factor = 2.5, exponent = 0.35</li><li>Embedded: effort factor = 3.6, exponent = 1.20; schedule factor = 2.5, exponent = 0.32<br> + </li> +</ul> +Thus, if you want to use sloccount but the project is actually semidetached, +you can use "--effort 3.0 1.12 --schedule 2.5 0.35" as options to sloccount +to get a more accurate estimate.<br> +<br> +For more accurate estimates, you can use the intermediate COCOMO models. + For intermediate COCOMO, use the following figures:<br> +<ul> + <li>Organic: effort base factor = 2.3, exponent = 1.05; schedule factor = 2.5, exponent = 0.38</li> + <li>Semidetached: effort base factor = 3.0, exponent = 1.12; schedule factor = 2.5, exponent = 0.35</li> + <li>Embedded: effort base factor = 2.8, exponent = 1.20; schedule factor = 2.5, exponent = 0.32<br> + </li> +</ul> +The intermediate COCOMO values for schedule are exactly the same as the basic +COCOMO model; the starting effort values are not quite the same, as discussed +in Boehm's book. However, in the intermediate COCOMO model, you don't +normally use the effort factors as-is, you use various corrective factors +(called cost drivers). To use these corrections, you then consider +all the cost drivers, and multiply them by the effort base factor, to determine +the final effort factor. Here are the cost drivers (from Boehm's book, +table 8-2 and 8-3):<br> +<br> +<table cellpadding="2" cellspacing="2" border="1" width="100%"> + + + <tbody> + <tr> + <td valign="top" rowspan="1" colspan="2">Cost Drivers<br> + </td> + <td valign="top" rowspan="1" colspan="6">Ratings<br> + </td> + </tr> + <tr> + <td valign="top">ID<br> + </td> + <td valign="top">Driver Name<br> + </td> + <td valign="top">Very Low<br> + </td> + <td valign="top">Low<br> + </td> + <td valign="top">Nominal<br> + </td> + <td valign="top">High<br> + </td> + <td valign="top">Very High<br> + </td> + <td valign="top">Extra High<br> + </td> + </tr> + <tr> + <td valign="top">RELY<br> + </td> + <td valign="top">Required software reliability<br> + </td> + <td valign="top">0.75 (effect is slight inconvenience)<br> + </td> + <td valign="top">0.88 (easily recovered losses)<br> + </td> + <td valign="top">1.00 (recoverable losses)<br> + </td> + <td valign="top">1.15 (high financial loss)<br> + </td> + <td valign="top">1.40 (risk to human life)<br> + </td> + <td valign="top"><br> + </td> + </tr> + <tr> + <td valign="top">DATA<br> + </td> + <td valign="top">Database size<br> + </td> + <td valign="top"><br> + </td> + <td valign="top">0.94 (database bytes/SLOC < 10)<br> + </td> + <td valign="top">1.00 (D/S between 10 and 100)<br> + </td> + <td valign="top">1.08 (D/S between 100 and 1000)<br> + </td> + <td valign="top">1.16 (D/S > 1000)<br> + </td> + <td valign="top"><br> + </td> + </tr> + <tr> + <td valign="top">CPLX<br> + </td> + <td valign="top">Product complexity<br> + </td> + <td valign="top">0.70 (mostly straightline code, simple arrays, simple expressions)<br> + </td> + <td valign="top">0.85<br> + </td> + <td valign="top">1.00<br> + </td> + <td valign="top">1.15<br> + </td> + <td valign="top">1.30<br> + </td> + <td valign="top">1.65 (microcode, multiple resource scheduling, device timing dependent coding)<br> + </td> + </tr> + <tr> + <td valign="top">TIME<br> + </td> + <td valign="top">Execution time constraint<br> + </td> + <td valign="top"><br> + </td> + <td valign="top"><br> + </td> + <td valign="top">1.00 (<50% use of available execution time)<br> + </td> + <td valign="top">1.11 (70% use)<br> + </td> + <td valign="top">1.30 (85% use)<br> + </td> + <td valign="top">1.66 (95% use)<br> + </td> + </tr> + <tr> + <td valign="top">STOR<br> + </td> + <td valign="top">Main storage constraint<br> + </td> + <td valign="top"><br> + </td> + <td valign="top"><br> + </td> + <td valign="top">1.00 (<50% use of available storage)</td> + <td valign="top">1.06 (70% use)<br> + </td> + <td valign="top">1.21 (85% use)<br> + </td> + <td valign="top">1.56 (95% use)<br> + </td> + </tr> + <tr> + <td valign="top">VIRT<br> + </td> + <td valign="top">Virtual machine (HW and OS) volatility<br> + </td> + <td valign="top"><br> + </td> + <td valign="top">0.87 (major change every 12 months, minor every month)<br> + </td> + <td valign="top">1.00 (major change every 6 months, minor every 2 weeks)</td> + <td valign="top">1.15 (major change every 2 months, minor changes every week)<br> + </td> + <td valign="top">1.30 (major changes every 2 weeks, minor changes every 2 days)<br> + </td> + <td valign="top"><br> + </td> + </tr> + <tr> + <td valign="top">TURN<br> + </td> + <td valign="top">Computer turnaround time<br> + </td> + <td valign="top"><br> + </td> + <td valign="top">0.87 (interactive)<br> + </td> + <td valign="top">1.00 (average turnaround < 4 hours)<br> + </td> + <td valign="top">1.07<br> + </td> + <td valign="top">1.15<br> + </td> + <td valign="top"><br> + </td> + </tr> + <tr> + <td valign="top">ACAP<br> + </td> + <td valign="top">Analyst capability<br> + </td> + <td valign="top">1.46 (15th percentile)<br> + </td> + <td valign="top">1.19 (35th percentile)<br> + </td> + <td valign="top">1.00 (55th percentile)<br> + </td> + <td valign="top">0.86 (75th percentile)<br> + </td> + <td valign="top">0.71 (90th percentile)<br> + </td> + <td valign="top"><br> + </td> + </tr> + <tr> + <td valign="top">AEXP<br> + </td> + <td valign="top">Applications experience<br> + </td> + <td valign="top">1.29 (<= 4 months experience)<br> + </td> + <td valign="top">1.13 (1 year)<br> + </td> + <td valign="top">1.00 (3 years)<br> + </td> + <td valign="top">0.91 (6 years)<br> + </td> + <td valign="top">0.82 (12 years)<br> + </td> + <td valign="top"><br> + </td> + </tr> + <tr> + <td valign="top">PCAP<br> + </td> + <td valign="top">Programmer capability<br> + </td> + <td valign="top">1.42 (15th percentile)<br> + </td> + <td valign="top">1.17 (35th percentile)<br> + </td> + <td valign="top">1.00 (55th percentile)<br> + </td> + <td valign="top">0.86 (75th percentile)<br> + </td> + <td valign="top">0.70 (90th percentile)<br> + </td> + <td valign="top"><br> + </td> + </tr> + <tr> + <td valign="top">VEXP<br> + </td> + <td valign="top">Virtual machine experience<br> + </td> + <td valign="top">1.21 (<= 1 month experience)<br> + </td> + <td valign="top">1.10 (4 months)<br> + </td> + <td valign="top">1.00 (1 year)<br> + </td> + <td valign="top">0.90 (3 years)<br> + </td> + <td valign="top"><br> + </td> + <td valign="top"><br> + </td> + </tr> + <tr> + <td valign="top">LEXP<br> + </td> + <td valign="top">Programming language experience<br> + </td> + <td valign="top">1.14 (<= 1 month experience)<br> + </td> + <td valign="top">1.07 (4 months)<br> + </td> + <td valign="top">1.00 (1 year)<br> + </td> + <td valign="top">0.95 (3 years)<br> + </td> + <td valign="top"><br> + </td> + <td valign="top"><br> + </td> + </tr> + <tr> + <td valign="top">MODP<br> + </td> + <td valign="top">Use of "modern" programming practices (e.g. structured programming)<br> + </td> + <td valign="top">1.24 (No use)<br> + </td> + <td valign="top">1.10<br> + </td> + <td valign="top">1.00 (some use)<br> + </td> + <td valign="top">0.91<br> + </td> + <td valign="top">0.82 (routine use)<br> + </td> + <td valign="top"><br> + </td> + </tr> + <tr> + <td valign="top">TOOL<br> + </td> + <td valign="top">Use of software tools<br> + </td> + <td valign="top">1.24<br> + </td> + <td valign="top">1.10<br> + </td> + <td valign="top">1.00 (basic tools)<br> + </td> + <td valign="top">0.91 (test tools)<br> + </td> + <td valign="top">0.83 (requirements, design, management, documentation tools)<br> + </td> + <td valign="top"><br> + </td> + </tr> + <tr> + <td valign="top">SCED<br> + </td> + <td valign="top">Required development schedule<br> + </td> + <td valign="top">1.23 (75% of nominal)<br> + </td> + <td valign="top">1.08 (85% of nominal)<br> + </td> + <td valign="top">1.00 (nominal)<br> + </td> + <td valign="top">1.04 (130% of nominal)<br> + </td> + <td valign="top">1.10 (160% of nominal)<br> + </td> + <td valign="top"><br> + </td> + </tr> + + + + + </tbody> +</table> +<br> +<br> +<br> +So, once all of the factors have been multiplied together, you can +then use the "--effort" flag to set more accurate factors and exponents.<br> +<br> +For example, imagine that you're examining a fairly simple application that +meets the "organic" requirements. Organic projects have a base factor +of 2.3 and exponents of 1.05, as noted above. We then examine all the +factors to determine a corrected base factor. For this example, imagine +that we determine the values of these cost drivers are as follows:<br> +<br> +<table cellpadding="2" cellspacing="2" border="1" width="100%"> + + <tbody> + <tr> + <td valign="top" rowspan="1" colspan="2">Cost Drivers<br> + </td> + <td valign="top" rowspan="1" colspan="2">Ratings<br> + </td> + </tr> + <tr> + <td valign="top">ID<br> + </td> + <td valign="top">Driver Name<br> + </td> + <td valign="top">Rating<br> + </td> + <td valign="top">Multiplier<br> + </td> + </tr> + <tr> + <td valign="top">RELY<br> + </td> + <td valign="top">Required software reliability<br> + </td> + <td valign="top">Low - easily recovered losses<br> + </td> + <td valign="top">0.88<br> + </td> + </tr> + <tr> + <td valign="top">DATA<br> + </td> + <td valign="top">Database size<br> + </td> + <td valign="top">Low<br> + </td> + <td valign="top">0.94<br> + </td> + </tr> + <tr> + <td valign="top">CPLX<br> + </td> + <td valign="top">Product complexity<br> + </td> + <td valign="top">Nominal<br> + </td> + <td valign="top">1.00<br> + </td> + </tr> + <tr> + <td valign="top">TIME<br> + </td> + <td valign="top">Execution time constraint<br> + </td> + <td valign="top">Nominal<br> + </td> + <td valign="top">1.00<br> + </td> + </tr> + <tr> + <td valign="top">STOR<br> + </td> + <td valign="top">Main storage constraint<br> + </td> + <td valign="top">Nominal<br> + </td> + <td valign="top">1.00<br> + </td> + </tr> + <tr> + <td valign="top">VIRT<br> + </td> + <td valign="top">Virtual machine (HW and OS) volatility<br> + </td> + <td valign="top">Low (major change every 12 months, minor every month)<br> + </td> + <td valign="top">0.87<br> + </td> + </tr> + <tr> + <td valign="top">TURN<br> + </td> + <td valign="top">Computer turnaround time<br> + </td> + <td valign="top">Low (interactive)<br> + </td> + <td valign="top">0.87<br> + </td> + </tr> + <tr> + <td valign="top">ACAP<br> + </td> + <td valign="top">Analyst capability<br> + </td> + <td valign="top">Nominal (55th percentile)<br> + </td> + <td valign="top">1.00<br> + </td> + </tr> + <tr> + <td valign="top">AEXP<br> + </td> + <td valign="top">Applications experience<br> + </td> + <td valign="top">Nominal (3 years)<br> + </td> + <td valign="top">1.00<br> + </td> + </tr> + <tr> + <td valign="top">PCAP<br> + </td> + <td valign="top">Programmer capability<br> + </td> + <td valign="top">Nominal (55th percentile)<br> + </td> + <td valign="top">1.00<br> + </td> + </tr> + <tr> + <td valign="top">VEXP<br> + </td> + <td valign="top">Virtual machine experience<br> + </td> + <td valign="top">High (3 years)<br> + </td> + <td valign="top">0.90<br> + </td> + </tr> + <tr> + <td valign="top">LEXP<br> + </td> + <td valign="top">Programming language experience<br> + </td> + <td valign="top">High (3 years)<br> + </td> + <td valign="top">0.95<br> + </td> + </tr> + <tr> + <td valign="top">MODP<br> + </td> + <td valign="top">Use of "modern" programming practices (e.g. structured programming)<br> + </td> + <td valign="top">High (Routine use)<br> + </td> + <td valign="top">0.82<br> + </td> + </tr> + <tr> + <td valign="top">TOOL<br> + </td> + <td valign="top">Use of software tools<br> + </td> + <td valign="top">Nominal (basic tools)<br> + </td> + <td valign="top">1.00<br> + </td> + </tr> + <tr> + <td valign="top">SCED<br> + </td> + <td valign="top">Required development schedule<br> + </td> + <td valign="top">Nominal<br> + </td> + <td valign="top">1.00<br> + </td> + </tr> + + + + + </tbody> +</table> +<br> +By multiplying these driver values together in this example, we compute:<br> +<pre>0.88*0.94*1*1*1*0.87*0.87*1*1*1*0.90*0.95*0.82*1*1</pre> +The correction from these is 0.438964094, which you multiply by the base +factor (2.3 in this case) to determine a final effort factor. For this +example, the final factor for the effort calculation is 1.01. You would then +invoke sloccount with "--effort 1.01 1.05" to pass in the corrected factor +and exponent. You don't need to use "--schedule" to set the factors +(they default to the values for organic model), but you can set them manually +anyway by setting "--schedule 2.5 0.38". You <i>do</i> need to use the --schedule option for embedded and semidetached projects. The final command would be:<br> +<br> +sloccount --effort 1.01 1.05 --schedule 2.5 0.38 my_project<br> +<br> +<br> +<br> +<br> +<br> +<br> +</body></html>
\ No newline at end of file |